Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
A research paper
Effects of preparation methods on the performance of InZr/SAPO-34 catalysts for CO2 hydrogenation to light olefins
GUO Shuai, FENG Likui, YU Zhiyong, XU Di, LIU Kaidi, SONG Xiaoning, CHENG Yijie, CAO Qiuyang, WANG Guanghui, DING Mingyue
 doi: 10.1016/S1872-5813(24)60433-0
Abstract(9) HTML(9) PDF 3758KB(3)
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Light olefins are of great importance as chemical raw materials, and ethylene is a crucial symbol to evaluate the development level of petrochemical industry. Catalytic hydrogenation of CO2 to light olefins is one of the most vital approaches to utilize CO2 with high-valued added. InZr/SAPO-34 catalysts show prominent potential in research and application because of their high light olefins selectivity and high stability in CO2 hydrogenation. In this study, the effects of different preparation methods of InZr/SAPO-34 catalysts for CO2 hydrogenation to light olefins were studied in depth. We found that the catalyst prepared by co-precipitation method showed the highest catalytic activity, and the catalyst prepared by sol-gel-deposition method showed the highest light olefins selectivity. The structure-activity relationship of InZr/SAPO-34 catalysts were revealed by various characterization methods.
A research paper
Effect of Al source on the physicochemical properties of Cu-Al spinel catalysts and the catalytic performance for reverse water gas shift
LIU Yajie, KANG Hefei, LU Ye, ZHANG Peng, GE Hui
 doi: 10.19906/j.cnki.JFCT.2024013
Abstract(0) HTML(0) PDF 1620KB(0)
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The excessive of fossil fuels has caused a swift rise in global carbon dioxide levels, resulting in severe climate change and environmental pollution. The research on the conversion of CO2 into high value-added chemicals is of great significance for CO2 reduction. Due to the high chemical activity of CO, a first conversion of CO2 to CO is meaningful, which makes the subsequent conversions become easier. Therefore, the reverse water gas shift reaction is considered to be an important intermediate step of CO2 hydrogenation to methanol, ethanol and other carbon-containing high value-added industrial products. For the reverse water gas shift reaction, several catalyst systems were researched, including supported catalysts, mixed metal oxide catalysts and transition metal carbide catalysts. Among these catalysts, Cu-based catalysts were widely reported owing to the high activity and CO selectivity. Recently, we found that Cu-Al spinel catalysts can be used as the efficient sustained release catalysts for reverse water gas shift reaction. High surface area pseudo-boehmite acts as an appropriate Al source for the synthesis of Cu-Al spinel catalysts by the mechanochemical method. However, the impurity elements in pseudo-boehmites showed significant influence on the formation and properties of Cu-Al spinel, and the catalytic performance for reverse water gas shift reaction. To unravel this point, four pseudo-boehmites with unequal contents of impurity elements (Na, Fe, Si, and S) and copper hydroxide were used for the synthesis of Cu-Al spinel solid solution catalysts by both high-energy ball milling and solid-phase calcination procedures. The physicochemical properties of the catalysts were characterized by ICP-AES, TG, XRD, H2-TPR, and BET methods, and the catalytic performances were investigated in reverse water gas shift reaction. The results showed that impurity elements in pseudo-boehmite samples had significant effects on the crystal property, reducibility, texture property and catalytic performance of the Cu-Al spinel catalysts. Specifically, Si facilitated the synthesize of high specific surface area catalysts but was detrimental to the formation of Cu-Al spinel, thus leading to a low catalytic activity. Cu-Al spinel catalysts with a small amount of Na and Fe also showed low catalytic activities. S species would be decomposed and removed during the precursor calcination step at high temperature of 950 ℃, thus giving little effect on the catalytic activity. Importantly, the catalyst synthesized based on the pseudo-boehmite with the lowest content of impurity elements had the highest content of hardly-reducible spinel, and exhibited the highest catalytic activity for CO2 hydrogenation to CO. In addition, the Cu-Al spinel catalyst with the highest catalytic activity was selected for the in-situ DRIFTS and CO2-TPD-MS characterizations. The results showed that the formate species, including monodentate formate on Al, bidentate formate on Al, and bidentate formate on Cu, were intermediate species of CO2 hydrogenation to CO over Cu-Al spinel catalysts. Notably, low peak intensities were detected with monodentate formate on Al and bidentate formate on Cu, but the bidentate formate on Al showed higher peak intensity. Especially, the content of bidentate formate on Al was in line with the catalytic activity at different reaction time, implying that the bidentate formate on Al was the main intermediate. This work provides guidance to catalyst synthesis using pseudo-boehmite as raw material.
Refined Ni, Co-Induced Synthesis of NiCoP Nanoparticles Uniformly Embedded in NCNTs: A Robust Dual-Functional Electrocatalyst for Water Splitting
ZHANG Xupeng, ZHAN Junling, WANG Ying, LIU Qun, ZHANG Yu, WANG Jiabo, CHEN Li
 doi: 10.1016/S1872-5813(24)60446-9
Abstract(0) HTML(0) PDF 11764KB(0)
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Ni, Co-induced highly distributed NiCoP nanoparticles embedded nitrogen-doped carbon nanotubes (NCNTs) (NiCo/NiCoP-NCNTs) were directly synthesized by a one-step phosphorization and carbonization process. As a bifunctional electrocatalyst for water splitting, NiCo/NiCoP NCNTs show impressive catalytic performance with an overpotential of only 206 mV for the hydrogen evolution reaction and 360 mV for the oxygen evolution reaction in 0.5 M H2SO4 and 1 M KOH solutions, respectively. In addition, NiCo/NiCoP NCNTs maintain a stable cell voltage of 1.68 V at 10 mA cm-2 with only a 10% decrease in current density over 48 hours, showing remarkable stability. The improved catalytic activity can be attributed to the integration of NiCoP nanoparticles and the synergies between NCNTs and NiCo alloy. Additionally, the improved electrocatalytic performance can be attributed to the increased electrochemically active surface area and the reduced electron transfer resistance of the NiCo/NiCoP-NCNTs. Overall, the NiCo/NiCoP-NCNTs demonstrated significant performance for advanced water electrolysis applications.
A research paper
Effect of zinc content on the structure of Zn species and catalytic properties over Zn/ZSM-5
GENG Rui, LIU Yacong, NIU Xianjun, DONG Mei, FAN Weibin, QIN Zhangfeng, WANG Jianguo
 doi: 10.19906/j.cnki.JFCT.2023089
Abstract(57) HTML(4) PDF 2321KB(10)
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Studying the status and distribution of Zn species on Zn/ZSM-5 zeolite catalysts were of great significance for determining the active centers and establishing structure-activity relationships in the ethylene aromatization process. The effect of zinc contents of Zn/ZSM-5 zeolites prepared by incipient-wetness impregnation method on catalytic performances in ethylene aromatization were investigated. The structures and acidic properties of the catalyst were studied through X-ray powder diffraction (XRD), N2 adsorption/desorption, and infrared spectra for pyridine adsorption (Py-FTIR). Besides, inductively coupled plasma-atomic emission spectrum (ICP), diffuse reflectance ultraviolet-visible spectrum (UV-vis DRS), extended X-ray absorption fine structure (EXAFS) and linear combination fitting (LCF) analysis on X-ray Absorption near edge spectra (XANES) had finely analyzed the structure and transition of Zn species and the losing rate of Zn species on HZSM-5 molecular sieve catalyst during ethylene aromatization process. The results showed that the introduction of Zn was advantage to improve the selectivity of aromatics hydrocarbon, and Zn contents of the catalyst had obvious influence on the structures, acidic properties, and the status of Zn species, as well as the catalytic performance of Zn/ZSM-5 catalysts. At low zinc loading, 1.5%-Zn(IM)/Z5 catalyst with more active 6-fold coordinated ZnOH+ species (55%) showed the highest selectivity to aromatics and catalyst stability. With the increase of zinc amount, the excessive Zn contents not only covered the acid sites and blocked the pore channel, but also changed the local coordination structure and state of Zn species. It was confirmed that the oxidizability of Zn species and the coordination number around Zn sites decreased, accompanied by a weakening of the interaction between Zn and zeolite, leading to the formation of large amounts of 4-fold coordinated ZnO clusters and ZnO crystallites. In the 4%-Zn(IM)/Z5 catalyst, Zn species composed of multi characteristics from ZnOH+, ZnO clusters inside the pores, and ZnO crystals on the external surface with relative contributions of 23.5%, 56.1%, and 20.4%, respectively. It meant that ZnO clusters and ZnO crystallites became the main component at the high Zn content. Furthermore, ZnO species located on the outer surface of Zn/ZSM-5 catalysts were easily reduced by H2 and then transported as zinc vapor to the outer surface, which eventually lead to the loss of Zn species from the catalyst and the decline of the catalytic performance of Zn/ZSM-5 catalyst. The relative proportion of ZnOH+ decreased with that of ZnO clusters and ZnO crystallites correspondingly increased considerably with the increase of Zn loading on ZSM-5, accompanied with the elevated rate for Zn losing, and shortened catalyst life. Therefore, a positively correlated between the content of ZnOH+ obtained through the UV-vis DRS and LCF analysis on XANES and the rate of aromatics formation was established, further confirming the catalytic nature of ZnOH+ as the active center, which played an important role in the aromatization reaction that enhancing the formation of aromatic hydrocarbons. Meanwhile, ZnO on the outer surface of Zn/ZSM-5 catalysts was the main species that losing from catalyst, and influenced the catalytic properties on a certain degree.
A research paper
Photocatalytic promotion of benzylamine C-N coupling by oxygen vacancies in bismuth oxychloride@nanocellulose composites
WANG Xiaoxia, SUN Long, QIN Li, SU Jing, WANG Jiajia
 doi: 10.1016/S1872-5813(24)60437-8
Abstract(14) HTML(6) PDF 3927KB(3)
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Bismuth oxychloride (BiOCl) is a promising semiconductor photocatalytic material, but the wide optical bandgap limits its scope of application in some important photocatalytic fields. In this work, nanocellulose (CNC) was used as a carrier to prepare composite photocatalysts by stirring BiOCl@CNC at room temperature. A series of characterizations show that a large number of hydroxyl groups in CNC can be tightly bound to BiOCl through hydrogen bonding, thus abundant oxygen vacancies are constructed in the material, which greatly and thus significantly enhance its visible photocatalytic performance. C−N coupling reaction of benzylamine under visible light was used as the target reaction to evaluate the performance of BiOCl@CNC and the mechanism was studied. Firstly, the reaction conditions were optimized, and the optimal condition was obtained as follows: 1.0 mmol of benzylamine, 20 mg of BiOCl@CNC were added to CH3CN in oxygen atmosphere for 20 h using 30 W white LED lamp as the light source. Subsequently, substrate expansion experiments were conducted, and the results showed that, BiOCl@CNC exhibited good adaptability and excellent stability to reactants containing different substituents. Through free radical capture experiments, it has been shown that electrons generate superoxide radicals with the assistance of oxygen vacancies, and form the final product with amine cation radical intermediates. This work not only enriches the application of Bi based composite semiconductors, but also provides new ideas for the synthesis of N-benzylene butylamine.
A research paper
Preparation of porous materials by ultrasound-intensified acid leaching of high-carbon component in coal gasification fine slag
LI Cuicui, HAN Rui, ZHOU Anning, ZHANG Ningning, GUO Kaiqiang, CHEN Heng, CHEN Xiaoyi, LI Zhen, WANG Junzhe
 doi: 10.1016/S1872-5813(23)60402-5
Abstract(53) HTML(41) PDF 12965KB(8)
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Coal gasification fine slag is one of the by-products from clean and efficient utilization of coal, and its resource utilization is extremely urgent. In this work, a high carbon fraction with a fixed carbon content higher than 60% was obtained by simple sieving of gasification fine slag, from which a porous material was prepared by ultrasonic acid leaching method. The adsorption performance of porous materials, being used as treatment of radioactive iodine in nuclear wastewater, is characterized by iodine adsorption value. The effects of ultrasound time, ultrasound power, acid concentration, and temperature on the iodine adsorption performance and compositional structure of the porous materials were systematically investigated by combining the results of SEM, BET, XRD, and FTIR. The mechanisms of ultrasound-enhanced acid leaching on compositional structure of residual carbon and migration and transformation laws of the ash constituents were explored and summarized. The results show that the porous material prepared under conditions of acid concentration of 4 mol/L, acid immersion temperature of 50 ℃, ultrasonic power of 210 W, and ultrasonic time of 1.5 h has the best iodine adsorption performance of 468.53 mg/g, with a specific surface area of 474.97 m2/g, and possesses a rich pore structure with predominant mesopores. The order of each factor on the iodine adsorption performance is: sonication time > acid concentration > sonication power > acid immersion temperature. The mechanism of ultrasonic enhanced acid leaching is that ultrasonic cavitation and mechanical wave action firstly enhance dissociation of carbon-ash adherent particles, thus making desorption of ash particles blocked in pore channels of the gasification slag to increase its connectivity; secondly, lead to generation of cracks on surface of the carbon and ash particles to enhance accessibility of inorganic components inside the carbon particles; and thirdly, enhance the acid leaching process by increasing mass transfer rate to strengthen leaching effect of inorganic components in the gasification slag.
Methane catalytic combustion over flame spray pyrolysis-synthesized Pd-Pt/CeO2 catalyst
WU Linyuan, WANG Yi, CHEN Zhaoying, TIAN Qingling, WANG Linru, FU Zijun, ZHAO Ning, WANG Xiaobo, HUANG Xin
 doi: 10.19906/j.cnki.JFCT.2023083
Abstract(65) HTML(34) PDF 26760KB(16)
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Flame spray pyrolysis (FSP) is a versatile, rapid, and scalable preparation technique for the nanocatalysts. CeO2 and Pt-CeO2 carriers, Pd-Pt-CeO2 catalyst were synthesized by flame spray pyrolysis, and then Pd-Pt bimetallic catalysts were prepared by impregnation method, and as-obtained Pd-Pt catalysts were tested in the methane combustion. The physicochemical properties of the catalysts were characterized by ICP, XRD, TEM, BET, H2-TPR, XPS, and Raman. TEM results showed that Pd and Pt species were highly dispersed in CeO2 carriers in Pd-Pt/CeO2 catalysts. Compared with the Pd-Pt-CeO2(OS-FSP) catalyst prepared by one-step flame spray pyrolysis, the catalytic activity of the Pd-Pt/CeO2(0.25)-WI prepared by co-impregnation was higher, with its t50 reduced by 60 ℃, and no deactivation was seen for 60 h. It is attributed to the fact that the Pd-Pt/CeO2(0.25)-WI catalyst has a higher molar ratio of Pd0/Pd2+ and Ce3+/Ce4+ on the surface of the catalyst and more lattice oxygen, resulting in an excellent performance during the methane combustion.
Preparation of eggshell supported Co3O4 catalyst and tested for N2O decomposition
HU Xiaobo, FENG Linyan, WU Ruifang, WANG Yongzhao, ZHAO Yongxiang
 doi: 10.19906/j.cnki.JFCT.2023079
Abstract(53) HTML(24) PDF 20892KB(10)
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A series of Co3O4/eggshell catalysts with different Co3O4 contents were prepared by the deposition-precipitation method using discarded eggshells as supports, and tested for the catalytic reaction of N2O decomposition on a fixed-bed continuous flow micro-reactor. The activity test results show that the catalyst exhibits higher activity towards N2O decomposition when the mass fraction of Co3O4 is 20%, with a specific activity of 4.3 times to that of pure Co3O4 (reaction temperature 440 ℃). At the same time, it shows strong resistance to 3% O2, 3.3% H2O and/or 2.0×10−4 NO in feed. Various characterization results indicate that the predominant composition of eggshell is CaCO3, which has a close incorporation with Co3O4. The strong interaction between CaCO3 and Co3O4 contributes to producing more oxygen vacancies and Co3+ in the 20% Co3O4/eggshell catalyst. The redox performance of Co3O4 is improved, and the Co−O bond is effectively weakened. In addition, it helps to increase the strength and amount of basic sites on the catalyst surface, making it easily transfer electrons and promote N2O decomposition.
A research paper
Photo-induced in-situ synthesis of Cu2O@C nanocomposite for efficient photocatalytic evolution of hydrogen
LI Na, MAO Shuhong, YAN Wenjun, ZHANG Jing
 doi: 10.1016/S1872-5813(23)60400-1
Abstract(107) HTML(36) PDF 12138KB(21)
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Cuprous oxide (Cu2O) is an ideal visible light catalyst owing to its narrow band gap, environmental benignity and abundant storage; however, the fast recombination of photogenerated charge carriers and poor stability of Cu2O has impeded its application in photocatalysis. Herein, we demonstrate that Cu2O@C nanocomposite can spontaneously evolve from a methanol aqueous solution containing cupric ions under the induction of irradiation. Compared with the traditional carbon coating method, the Cu2O@C nanocomposite obtained by the photo-induced in-situ synthesis can reserve superior original characteristics of the semiconductor under mild reaction conditions, promote the charge transfer and enhance the separation efficiency of charge carriers; in addition, the carbon shells can also effectively prevent Cu2O from photo-corrosion. As a result, the Cu2O@C nanocomposite exhibits excellent photocatalytic activity in the hydrogen evolution in comparison with the Cu2O particles; the H2 evolution rate over the Cu2O@C nanocomposite reaches 1.28 mmol/(g·h) under visible light, compared with the value of 0.065 mmol/(g·h) over Cu2O. Moreover, the Cu2O@C nanocomposite displays good cycle stability, viz., without any deactivation in the catalytic activity after five cycles.
The promotional effects of ZrO2 modification on the activity and selectivity of Co/SiC catalysts for Fischer-Tropsch synthesis
WANG Min, GUO Shupeng, XU Jinshan, LI Liuzhong, CHEN Congbiao, MA Zhongyi, JIA Litao, HOU Bo, LI Debao
 doi: 10.1016/S1872-5813(24)60439-1
Abstract(17) HTML(6) PDF 718KB(0)
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Co/SiC catalysts have exhibited excellent performance in Fischer-Tropsch synthesis reaction.,However, few research focuses on investigating the effect of SiC supports surface properties of on catalyst performance. In this study, ZrO2 was utilized to modify the SiC surface,leading to the preparation of a series of Co-ZrO2/SiC catalysts. The physicochemical properties of the catalyst were comprehensively analyzed by using N2 adsorption, XRD, H2-TPR, XPS analyses. Catalytic performance was evaluated using a fixed bed reactor, shedding light on the effect of ZrO2 modified SiC support on cobalt-based Fischer-Tropsch synthesis catalysts. The results indicated that ZrO2 surface modification on SiC resulted in an enhanced reduction degree of Co/SiC catalysts. Additionally, ZrO2 exhibited strong interaction with the amorphous phase on the SiC surface, thereby weakening the interaction between Co and the amorphous phase., This led to an increase in the electron density of cobalt species, consequently improving the selectivity of Co/SiC catalysts towards long-chain hydrocarbons.
Theoretical Calculations of Pyridine Adsorption on the Surfaces of Ti, Zr, N Doped Graphene
WANG Jucai, TANG Ke, SUN Xiaodi, HONG Xin
 doi: 10.1016/S1872-5813(24)60440-8
Abstract(14) HTML(4) PDF 5838KB(1)
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The removal of nitrides from diesel fuel has important significance for the environment and human health. The adsorption behaviour of Ti, Zr and N-doped and intrinsic graphene on pyridine, a typical basic nitride in diesel fuel, has been investigated by density functional methods in this paper. the corresponding adsorption energy, adsorption configurations, Mulliken charge transfer, differential charge density, and density of states were discussed. The results show that metal Ti and Zr doping can significantly enhance the adsorption energy between pyridine and graphene surfaces, and non-metal N doping can slightly increase the adsorption energy between pyridine and graphene surfaces. The magnitude of the adsorption energy of pyridine on the surface of graphene modified with different atoms was in the order of Ti doped graphene > Zr doped graphene > N doped graphene > intrinsic graphene, Pyridine could undergo N-Ti, N-Zr and π-π interactions with Ti and Zr doped graphene, and N-N, C-N and π-π interactions with N doped graphene and intrinsic graphene. Further analysis reveals that there are obvious electron transfer and chemical bond formation between pyridine and metallic Ti, Zr-doped graphene surfaces, while there is no chemical bond formation with non-metallic N-doped graphene and intrinsic graphene. Chemical adsorption interaction of pyridine with Ti, Zr-doped graphene, physical adsorption interaction with N-doped graphene and intrinsic graphene. Pyridine was more stable adsorption on the surface of Ti Zr-doped graphene.
Density functional theory study of adsorption of As2O3 on CeO2 surface by Fe, La doping and oxygen defects
LU Kunpeng, ZHANG Kaihua, ZHANG Kai
 doi: 10.19906/j.cnki.JFCT.2024005
Abstract(28) HTML(26) PDF 5259KB(8)
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Density functional theory (DFT) was used to study the adsorption behavior of As2O3 (g) on iron and lanthanum doped CeO2 (110) and oxygen-deficient LaCeO (110) surfaces, and the reasons for the arsenic adsorption capacity of LaCeO surface was significantly higher than that of FeCeO surface was explored. The results show that the adsorption effect of As2O3 (g) is closely related to the number of adsorption sites, adsorption energy, bond length and charge transfer amount. Ce and O atoms on the surface of pure CeO2 are both active sites, and the adsorption is mainly chemisorption, the absolute adsorption energy is greater than −4.22 eV, and the charge transfer amount is −0.19− −0.31 e. As2O3 has a negative charge and acts as a surface accepter, while CeO2 loses electrons and has a positive charge on the surface, which acts as a surface donor. The number of free electrons in the CeO2 conduction band gradually decreases, the conductivity decreases, and it is difficult to provide more electrons continuously, so the adsorption amount is small. Two adsorption sites are added on the surface of FeCeO (110): Fe top site and Bridge-2 Bridge site, where Fe top site is chemical adsorption and Bridge-2 Bridge site is physical adsorption. The gap doping of Fe changes the electron distribution and lattice structure on the surface of FeCeO, resulting in obvious deformation of the lattice and reducing the difficulty of bonding, thus increasing the configurational adsorption energy of some configurations. However, it does not change the charge transfer direction between As2O3 and FeCeO, thus not changing the surface adsorption form of As2O3. As2O3 is still adsorbed in the form of negative ions, which plays the role of surface acceptor, and the adsorption amount is small. LaCeO (110) has three new adsorption sites: La top site, Bridge-3 Bridge site and Hollow-2 vacancy, among which the La top site and Bridge-3 Bridge site are chemical adsorption. La doping changes the charge transfer direction between As2O3 and LaCeO, resulting in positive ion adsorption of As2O3 with electron loss and surface donor function. The electrons on the surface of LaCeO play the role of surface acceptor. With the progress of adsorption, the number of free electrons in the conduction band increases, and the conductivity increases. Therefore, the adsorption capacity of As2O3 on the surface of LaCeO increases. In the absence of O2, the number of chemical bonds and bond energy formed on the surface of LaCeO (110) with single O defect are smaller than those on the surface of LaCeO, and the charge transfer on the surface of the defect is less, so the adsorption energy decreases. In this case, As2O3 obtains electrons and acts as the surface donor, and the adsorption capacity is lower than that on the complete LaCeO surface. In the presence of O2, the adsorption energy and charge transfer number increase in the ortho-configuration after O2 supplementation with O defect. As2O3 is positively adsorbed in ionic form, and the adsorption energy is also higher than that on the intact LaCeO surface. The adsorption capacity of As2O3 is better than that on the LaCeO surface, indicating that O defect is conducive to the adsorption of As2O3 in the presence of O2.
review
The research progress of formation and control on the N-containing compound of biomass pyrolysis gas
WANG Fengchao, ZHU Hongyu, YIN Xiuli, XU Bin, LI Weizhen, LIU Huacai
 doi: 10.19906/j.cnki.JFCT.2023090
Abstract(33) HTML(7) PDF 10865KB(7)
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Biomass energy plays an important role in combating global warming and the depletion of fossil energy sources. Although different recovery technologies of biomass energy were utilized industrially, the development level of different recovery technologies varies. The application of biomass energy includes technologies such as combustion, pyrolysis, gasification, and fermentation. The pyrolysis technology is an efficient and economical method to utilize biomass energy, which combines the advantage of energy recovery and product diversification. However, the N-containing compounds in the biomass pyrolysis gas make the pyrolysis gas of low quality, which combustion leads to secondary pollution of air. This review summaries the research status of N-containing compounds in the biomass pyrolysis gas, mainly reviewing the differences in the thermos-gravimetric behavior of typical biomass and the four compositions in biomass (cellulose, hemicellulose, lignin, and proteins). There were significant differences in the thermos-gravimetric behavior of biomass with different material compositions, but the whole TG curve can be divided into three stages: in the first stage, the pyrolysis of easily decomposable components in biomass releases small molecule gases and steam; in the second stage, the pyrolysis of cellulose, hemicellulose, and lignin in biomass released a large amount of O-containing bio-oil; in the third stage, the volatile components attached to the surface of the bio-char were cracked again and condensation reaction occurs. The nitrogen content in biomass was high, and during the pyrolysis process, nitrogen migrated into the solid-liquid-gas three-phase, and the migration transformation process was extremely complex. This review also discussed the generation mechanism of N-containing compounds in biomass pyrolysis gas and analyzed the distribution and control research of N-containing compounds. The NH3 in the low-temperature pyrolysis gas was mainly derived from the direct pyrolysis of protein in biomass. With the increase of pyrolysis temperature, the biomass pyrolysis volatiles were cracked secondly to generate N-containing heterocyclic substances, nitriles, and cyclic amides, and further cracked to produce HCN. Under the high-temperature atmosphere, partial HCN reacts with ·H and generates NH3 with the biomass char catalysis, leading to a decrease in the concentration of HCN. The N-containing heterocyclic substances from the second cracking of volatiles were the main resource of HCNO, and HCNO has a relatively lower concentration and is easily reduced to HCN and NO. Thus, with the pyrolysis temperature increase, the main components of N-containing compounds in the pyrolysis gas were gradually converted from NH3 and HCNO to NO and HCN. When the temperature was 800 ℃, the concentration of NO accounted for 40% of the N-containing compounds in pyrolysis gas. While, at 900 ℃, NH3 and HNCO were barely detectable. At the same time, it pointed out the difficulties and challenges faced in the practical application of N-containing compound removal. It is necessary to establish a generalized mechanism for nitrogen conversion during the thermal conversion of biomass. The nitrogen transport and control mechanisms during biomass pyrolysis need to be further improved. And, the key research directions in the process optimization and economic analysis of N-containing control are further anticipated. This review aims to provide a theoretical basis and technology support for biomass pyrolysis gas purification.
A research paper
Surface reaction and lattice oxygen transfer in chemical looping oxidative coupling of methane: Molecular dynamics simulations
LI Wanying, CHEN Liangyong
 doi: 10.1016/S1872-5813(23)60412-8
Abstract(50) HTML(11) PDF 1887KB(5)
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Chemical looping oxidative coupling of methane (CL-OCM) is a promising methodology for ethylene production from methane. This article utilizes molecular dynamic (MD) simulation to assess the performance of eight metal oxide catalytic oxygen carriers in CL-OCM reactions. It also investigates the impact of reaction time and particle size on the efficiency of the most effective Mn2O3 COC. The results indicate that extending the reaction time appropriately enhances C2H4 selectivity and a C/O ratio of 1 is found to be the optimal size for Mn2O3-based CL-OCM. Furthermore, surface reactions and lattice oxygen transfer are analyzed by MD simulation in Mn2O3-based CL-OCM, providing deeply insights into the reaction mechanism. The findings reveal that the gas-phase dimerization of CH3 * to form C2H6 serves as the primary carbon coupling pathway in CL-OCM. In addition, there are two other carbon coupling pathways, both initiated by CH2 *. Methanol formation through surface combination of CH3 * and OH* represents an initial step in CL-OCM side reactions. Therefore, inhibiting methanol formation is crucial for enhancing C2 selectivity in CL-OCM. There exists a transformation of lattice oxygen and surface lattice oxygen plays a key role in methane activation. The quantity of lattice oxygen and difference in bulk lattice oxygen migration resistance are major factors influencing variations CH4 conversion and C2 selectivity. This study provides a new way to reaction mechanism exploration related to CL-OCM catalytic oxygen carriers.
Research progress of chemical catalysis for biomass-based furfural to nitrogen-containing compounds
CHEN Jiayue, LI Keming, HUANG Yaobing, LU Qiang
 doi: 10.19906/j.cnki.JFCT.2024007
Abstract(21) HTML(8) PDF 881KB(2)
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The utilization of biomass holds a great promise to partially replace the non-renewable fossil resources for the production of chemicals and materials for daily use, which could effectively mitigate the challenges associated with global resource scarcity. Furfural, a prominent biomass-derived platform compound derived from the dehydration of xylose in hemicellulose, which is widely used as the key intermediate or solvent in the petrochemicals, coating, pesticides, medicine, synthetic rubber, etc. At the same time, furfural can be converted into a series of high value-added chemicals and fuel, such as alcohols, acids, esters, nitriles, amines, and others due to its active C=O bonds and furan rings. Typical chemical reactions, such as reduction, oxidation, etherification, ammonia oxidation, reduction amination, ring rearrangements and others, are frequently used for the above conversions. Among various chemicals obtained from furfural conversions, nitrogen-containing compounds have attracted considerable attention, owing to the wide applications of such type molecules in the synthesis of drug molecules, bioplastics, and other functional materials. Therefore, using furfural as a raw material to synthesize bio-based nitrogenous compounds represents a cutting-edge research direction. In the presence of nitrogen sources, furfural can be transformed into diverse nitrogen-containing compounds through different reactions, such as reduction amination, ammonia oxidation, oxidative coupling, etc. Varied nitrogen sources (e.g. NH3, N2H4·H2O, NH4HCO2, CH3COONH4, (NH4)2CO3 and others), catalysts, reaction atmospheres, and temperatures can result in distinct target products during furfural conversions. Currently, domestic and foreign research groups have made significant progress on furfural conversions to different nitrogen-containing compounds. Therefore, this review aims to briefly outline the recent achievements in the synthesis of high-value nitrogen-containing compounds from furfural through catalytic conversions over different catalysts. The main content includes: (1) synthesizing amines by reduction aminations, e.g. primary, secondary, and tertiary amines; (2) nitriles production by ammonia oxidation; (3) producing amides by amidation; (4) preparing heterocyclic compounds, such as benzoheterocyclic, thiazole, pyrrole, indole, piperidine and pyridine via oxidative cyclization, decarbonylation-amination, reduction amination, hydrogenation, ring rearrangements. The influences of synthesis methods, catalyst types, reaction pathways, mechanisms, as well as the nitrogen sources, on product distributions were discussed in detail. Considering the pathways and products potentially affected by different nitrogen sources and reaction conditions, future breakthroughs in the synthesis of nitrogen-containing compounds from furfural can be anticipated from the following aspects: (1) By systematically considering the reaction processes and mechanisms, the construction of composite catalysts and precise adjustment of reaction conditions to integrate multiple reaction steps into one is a trend in this research area to attain more efficient and green conversion processes; (2) Combined experimental with theoretical investigations to comprehensively reveal the reaction pathways during the reaction of different nitrogen sources with furfural; (3) Exploration of new chemical conversion routes and catalysts for the production of more novel nitrogen-containing compounds, to further broaden the application areas of furfural based chemicals. In brief, this review provides a systematical review on the production of furfural based nitrogen-containing chemicals, which would benefit the communities working in biomass utilization areas, and also contribute to the establishment of knowledge of the furfural chemical family.
Recent contributions of photoionization mass spectrometry in the study of typical solid fuel pyrolysis
SHEN Yang, CUI Cunhao, LIU Haoran, REN Hairong, CAI Jianghuai, ZHOU Zhongyue, QI Fei
 doi: 10.1016/S1872-5813(23)60411-6
Abstract(29) HTML(6) PDF 25361KB(6)
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Pyrolysis, an economically viable method, thermochemically converts solid fuel into transportation fuels and value-added chemicals, such as clean gas, liquid fuels, and chemicals, alongside undesirable by-products. Photoionization mass spectrometry (PIMS) is a versatile technique for real-time process analysis, offering 'soft' ionization for complex analytes, detecting and analyzing ions during in-situ pyrolysis. This review focuses on recent applications of PIMS during pyrolysis of solid fuels (i.e. coal, biomass and energetic materials). It summarizes studies on mass spectrometric analysis combined with different reactors and highlights the benefits othrough online PIMS as a diagnostic tool for in situ analysis. It provides an overview of interplay between experimental advancements and models and discusses future perspectives, potential applications in support of mechanistic studies.
A research paper
Synthesis and hydrocracking performance of small crystal NiY zeolites
SUN Jinxiao, WANG Xiaohan, WEI Qiang, ZHOU Yasong
 doi: 10.1016/S1872-5813(24)60432-9
Abstract(35) HTML(13) PDF 3864KB(9)
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A series of small crystal Y-xNi zeolites with different amounts of Ni doping were synthesized by an in situ synthesis method, in which Ni precursors were introduced during the synthesis of small crystal Y zeolites. The active metal Ni was pre-impregnated into the framework of the Y zeolite. Y-xNi series zeolite and ASA were mechanically mixed as support and loaded with Ni and W to prepare Cat-xNi series hydrocracking catalysts. The hydrocracking performance was investigated using n-hexadecane as the reactant. The effects of Ni doping on the physicochemical properties of Y zeolite and catalysts were analyzed by means of characterization such as scanning electron microscopy (SEM), X-ray diffraction (XRD), N2-adsorption desorption, NH3 temperature programmed desorption (NH3-TPD), H2 temperature programmed reduction (H2-TPR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results show that Ni mainly replaces Al into the framework of Y zeolite. The appropriate incorporation of Ni into Y zeolite increases the relative crystallinity of Y zeolite and the number of Brønsted and Lewis acid sites. However, excessive Ni incorporation is detrimental to the crystallization of Y zeolite and excessive non-framework Ni species will cover the surface Brønsted acid sites. Ni doping weakened the metal-support interactions, increased the sulfation of the active metal, the stacking number and dispersion of NiWS, and modified the matching between the metal and acid sites on the catalyst. The results of the catalyst evaluation showed that the introduction of Ni was favorable to improve the selectivity and yield of the middle distillate products (C8−C12). That is, increasing the number of Brønsted acid sites and NiWS active sites at the same time, improving the synergistic effect between the metal sites and the acid sites, improving the conversion while avoiding over-cracking, and increasing the yield of the middle distillate products. The catalyst Cat-0.2Ni had a higher n-C16 conversion and C8−C12 product yield at the reaction temperature of 360 ℃, with the n-C16 conversion increased by 10.2 percentage points compared with that of Cat-0Ni, and the C8−C12 product yield was 65.4%. Therefore, the pre-impregnation of active metal Ni on Y zeolite can effectively regulate the balance between the Hydrogenation and cracking performance to improve the catalytic activity and the yield of middle distillate products.
A research paper
Promoted stability of Cu/ZnO/Al2O3 catalysts for methanol production from CO2 hydrogenation by La modification
NIU Mengmeng, JIANG Yanan, ZHANG Xian, ZHANG Cuijuan, LIU Yuan
 doi: 10.1016/S1872-5813(24)60438-X
Abstract(40) HTML(19) PDF 3064KB(16)
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Deactivation of Cu/ZnO/Al2O3 catalysts in CO2 hydrogenation to methanol reaction is one of the main reasons limiting their application. We synthesized a series of La modified Cu/ZnO/Al2O3 catalysts by adding different contents of La to improve the stability. In the 100 h short-term stability test at 200 ℃ under 3 MPa with a GHSV of 12000 mL/(g·h), the unmodified Cu/ZnO/Al2O3 catalysts degraded obviously over 100 h. In sharp contrast, the stability was significantly promoted by the addition of La. The best activity was achieved with 5% La added samples (4% CO2 conversion and 85% methanol selectivity). Which also showed impressive stability over 1000 h except about17% deactivation during the initial 190−220 h. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results revealed that the addition of 5% La improved the dispersion of Cu and Zn , inhibited the sintering of Cu, stabilized the Cu0/+ species and retarded oxidation of Cu in catalysts, which attributed to the high stability of the catalysts.
A research paper
Study on the enhancement mechanism of low-temperature SCR performance of ammonium persulfate coupled transition metal oxides modified carbon-based catalysts
XIAO Ling, HUANG Yan, QIAO Shufang, ZHAO Lingkui, LI Simi
 doi: 10.19906/j.cnki.JFCT.2024006
Abstract(8) HTML(6) PDF 2844KB(0)
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In recent years, carbon-based catalysts have received extensive attention in the field of NH3-SCR due to their unique advantages. In order to improve the performance of low-temperature NH3-SCR of carbon-based catalysts, V/OAC, Fe/OAC, Mn/OAC and Cu/OAC carbon-based catalysts were prepared by oxidizing and coupling transition metal oxides with ammonium persulfate. The mechanism of SCR performance enhancement of modified carbon-based catalysts was investigated by means of catalytic activity test, Physical adsorption, FT-IR, XPS, NH3-TPD, H2-TPR, EPR and other characterization methods. The results show that ammonium persulfate oxidation can introduce a large number of acidic oxygen-containing functional groups to the surface of activated carbon support, promote the formation of oxygen vacancy in transition metal oxides, and improve the surface acidity and redox performance of carbon-based catalysts, therefore the low temperature NH3-SCR performance of the carbon-based catalyst was improved. In particular, we found that oxidation of ammonium persulfate can induce the formation of lower valence states of transition metal elements (V, Fe, Mn,Cu ). Therefore, after oxidative modification of ammonium persulfate, the performance of V/OAC and Fe/OAC catalysts with low-priced metals in active components conducive to NH3-SCR reaction is significantly improved, the NO conversion of VOx/OAC and FeOx/OAC catalysts at 100 ℃ increased from 18.2% to 34.8% and from 34.2% to 55.6%, respectively; while the performance of Mn/OAC and Cu/OAC catalysts with high-priced metals in active components conducive to NH3-SCR reaction is limited, the conversion of NO at 100 ℃ only increased from 61.4% to 70.4% and from 61.3% to 69.7%. This work summarized the regulatory effect of ammonium persulfate oxidation modification on the surface metal states of carbon-based catalysts, which is helpful to deeply understand the regulation law of physical and chemical properties of carbon-based catalysts by oxidative modification of ammonium persulfate, and provide guidance and reference for the development of high-efficiency carbon-based denitrification catalysts.
A research paper
Study on the impact of using decarbonized gasification slag for CO2 mineralization and storage to prepare calcium carbonate
LI Xiangyu, LI Xu, FAN Panpan, BAO Weiren, CHANG Liping, WANG Jiancheng
 doi: 10.19906/j.cnki.JFCT.2024008
Abstract(24) HTML(7) PDF 6694KB(8)
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The gasification slag after carbon separation is difficult to realize effective utilization because of its high content of water and the presence of a small amount of residual carbon. To address these problems, a mineralization based on indirect carbonation to sequester CO2 and recycle calcium extraction to prepare nano-calcium carbonate process is proposed. The gasification slag after carbon separation mainly consists of CaO, Al2O3, Fe2O3, MgO, as well as some non-metallic components such as SiO2. Most of the metal components exist in amorphous form. After preliminary screening of acidic leaching agents, it was found that hydrochloric acid can effectively destroy the structure of gasification slag and dissolve the metal components in gasification slag. In this paper, the effects of leaching agent type, concentration, reaction time, temperature and liquid-solid ratio on the leaching rate of calcium from decarbonized gasification slag were investigated in detail. The results showed that the highest calcium leaching rate of 98.79% was achieved under the leaching conditions of 2 mol/L HCl, liquid-to-solid ratio of 20 mL/g, reaction temperature of 50 ℃ and reaction time of 90 min. Meanwhile, the effects of CO2 flow, temperature and time on the carbonation efficiency and precipitated calcium carbonate (PCC) crystal structure were investigated. In the carbonation stage, the main factor affecting carbonation efficiency is CO2 flow. This is because excessive CO2 will cause carbonic acid to form in the solution and partially dissolve the precipitated CaCO3, resulting in a sharp decrease in carbonation efficiency. And the carbonation efficiency gradually increases with the increase of reaction temperature. Generally speaking, increasing the temperature is beneficial for chemical reactions. However, owing to the exothermic nature of the carbonation reaction, the positive promotion effect of high temperature on the reaction process is weakened, and the solubility of CO2 in water is reduced, resulting in a slow decrease in carbonation efficiency. The effect of reaction time on carbonation process has the same trend as the change in reaction temperature. The highest carbonation efficiency could reach 99.59% by optimizing the carbonation reaction conditions. In addition, the reaction temperature and time significantly affected the calcium carbonate crystal structure and micromorphology. The formation of calcium carbonate crystals mainly goes through three stages. In the first stage, as the reaction time prolongs, disordered amorphous calcium carbonate rapidly dehydrates to form ordered calcium carbonate crystal structure. At high supersaturation, vaterite begins to nucleate and undergoes spherical growth through nucleation at the growth front. Gradually, the solubility of amorphous calcium carbonate gradually decreases, and vaterite continues to grow into polycrystalline spheres composed of roughly equal sized crystals. In the second stage, vaterite is formed under equilibrium conditions, and its crystal size almost no longer increases, leaving part of the remaining amorphous calcium carbonate dissolution and crystallization process. In the third stage, vaterite begins to decompose and forms calcite or aragonite through dissolution-recrystallization process. Experiments result have shown that vaterite and calcite are formed at low temperatures, and aragonite is formed when heated to a certain temperature. As the reaction time increases, the particle size of calcium carbonate gradually increases. Therefore, lowering the reaction temperature and time is more favorable to the formation of vaterite type calcium carbonate.
Experimental study on alkali lignin enhanced chemical looping gasification of pulverized coal char
GAO Xinglong, AN Fengxia, HU Yun, CHEN Guoqing, YI Qun, WU Xiaoyan, CAO Jinzeng, YAO Weishan, WEI Guoqiang
 doi: 10.19906/j.cnki.JFCT.2023078
Abstract(68) HTML(38) PDF 5447KB(11)
Abstract:
The pulverized coal char from the byproduct of China's coal coking industry has high yield and low activity, which is difficult to be directly recycled. The conventional thermochemical utilization method has harsh reaction conditions, catalyst deactivation and kinetic limitations. By using the alkali lignin from paper-making as a disposable catalyst, an alkali lignin enhanced chemical looping gasification method was constructed to treat coal coke powder, which can realize the collaborative resource utilization of industrial by-products. In this study, the reaction process of alkali lignin and coal char powder was studied by thermogravimetry and kinetic analysis. The thermal transformation experiment and kinetic analysis showed that alkali lignin could strengthen the chemical looping gasification process of pulverized coal char and promote the pyrolysis peak to move to low temperature. When the mass ratio of pulverized coal char to alkali lignin was 1∶3, the activation energy was 87.56% lower than that of coal coke powder alone, indicating that there was a synergistic effect between the two in the co pyrolysis process. The experiments in fixed bed reactor verified that the carbon conversion rate and the selectivity of syngas increased as the increasing of temperature and the content of alkali lignin and oxygen carrier, which effectively promoted the gasification reaction. However, excessive oxygen loading led to combustion reaction between syngas and lattice oxygen and reduce syngas selectivity. Under the optimal reaction conditions of 950 ℃, the mass ratio of coal char powder to alkali lignin is 1∶2, and the mass ratio of oxygen carrier to pulverized coal char/alkali lignin is 1∶1, the selectivity of syngas of alkali lignin/coal char powder in chemical looping gasification was 82.85%. This study provides a scientific basis for the resource utilization of alkali lignin and coal char powder.
Impact of B-site Cations of MgX2O4 (X=Mn, Fe, Cr) Spinels on the Chemical Looping Oxidative Dehydrogenation of Ethane to Ethylene
LIANG Xiaocen, WANG Xuemei, XING Zifan, MAO Min, SONG Da, LI Yang, LONG Tao, ZHOU Yuchao, CHEN Peili, HE Fang
 doi: 10.1016/S1872-5813(24)60434-2
Abstract(18) HTML(6) PDF 8230KB(2)
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Chemical looping oxidative dehydrogenation (CL-ODH) provides a multifunctional conversion platform that can take advantage of the selective oxidation of lattice oxygen in oxygen carrier to achieve high-valued ethane to ethylene conversion. In this study, we explored the effect of B-site element in MgX2O4 (X=Cr, Fe, or Mn) spinel-type oxygen carriers on the performance of ethane CL-ODH. The properties test and characterization of MgX2O4 spinel were tested by fixed bed and H2-TPR, O2-TPD, TG, in situ Raman, SEM, and TEM. The results showed that because MgCr2O4 only released a small amount of adsorbed surface oxygen, it tended to catalyze the conversion of ethane to coke and hydrogen. MgFe2O4 facilitated the deep oxidation of ethane into CO2 by providing more surface lattice oxygen. Meanwhile, since a significant amount of bulk lattice oxygen was released by the MgMn2O4 oxygen carrier, it could burn hydrogen in a targeted manner to advance the reaction and increased ethylene's selectivity. Thereby, MgMn2O4 achieved an ethane conversion of 73.7% with an ethylene selectivity of 81.46%. Furthermore, the MgMn2O4 catalyst demonstrated stable reactivity and an ethylene yield of about 62% in ethane CL-ODH over the 30 redox cycles. The screening tests indicated that the B-site elements in MgX2O4 spinel oxides could significantly influence their ability to supply lattice oxygen, thereby affecting their performance in ethane CL-ODH reaction.
Research on the 9,10-dihyroanthrancene assisted catalytic pyrolysis of pine over nitrogen-doped activated carbon for preparation of alkoxyphenols
LI Wentao, ZHANG Chengbo, LI Kai, NIU Qi, LI Jihong, LU Qiang, JIA Bao, GAO Lijuan
 doi: 10.19906/j.cnki.JFCT.2023081
Abstract(39) HTML(14) PDF 4733KB(3)
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In this study, nitrogen-doped activated carbon (NAC) was prepared from walnut shell and applied to the catalytic pyrolysis of pine for selective preparation of alkoxyphenols with 9,10-dihyroanthrancene (DHA) as the hydrogen donor. The effects of ammonia concentration on the physicochemical properties of NAC were investigated. The regulatory functions of DHA/pine ratio, pyrolysis temperature, and NAC/pine ratio on the generation of alkoxyphenols were revealed. The results showed that the pore structure and active sites distribution of NAC could be improved by proper ammonia concentration. The NAC prepared at ammonia concentration of 15% was the best for the production of alkoxylphenols. The yield of alkoxylphenols reached its maximum value of 5.27% at DHA/pine ratio of 3, pyrolysis temperature of 550 ℃, and NAC/pine mass ratio of 3, which was much higher than that from catalytic pyrolysis of pure pine (1.74%).
The effect of alkali and alkaline earth metals in biomass ash on the bio-oil components derived from biomass fast pyrolysis
DING Zixia, CAI Bo, CEN Kehui, CHEN Dengyu, MA Zhongqing
 doi: 10.19906/j.cnki.JFCT.2023076
Abstract(90) HTML(34) PDF 4109KB(13)
Abstract:
The alkali and alkaline earth metals (AAEMs) in biomass ash have a significant impact on the yield and component distribution of rapid plytic biooil. In this paper, corn straw is selected as the raw material. First, the effect of cascade deash removal pretreatment (distillation water, ammonium acetate and hydrochloric acid) on the selective removal of AAEMs and its biological oil components is studied, and then the effect of the type of AAEMs (K, Ca, Na and Mg), the concentration of chloride salt (0.5%, 2.5% and 5%), and the acid radical in metal salt(${\rm{SO}}_4^{2-} $, ${\rm{NO}}_3^- $, ${\rm{CO}}_3^{2-} $, ${\rm{HCO}}_3^- $, AC and ${\rm{PO}}_4^{3-} $)on the compound distribution of bio-oil was systematically investigated. The results show that in the process of ash removal pretreatment, with the deepening of the acidity of the ash removal solution, the removal rate of AAEMs gradually increases. According to the selective removal law of AAEMs in the process of cascade ash removal, their morphology in biomass can be divided into the following three groups, namely the water-soluble metal (K), the ion-exchanged metals (Ca and Mg), the acid-soluble metal (Na). The removal of AAEMs promoted the formation of levoglucosan (LG), while restrained the formation of ketones and furans. However, the incorporation of AAEMs in biomass presented an opposite variation trend. The AAEMs would act as catalyst during biomass pyrolysis which promoted the secondary cracking of LG, leading to the reduction of LG and increase of ketones and furans. In addition, different acid roots in potassium salt also have remarkable influence on the secondary cracking reaction of LG and the rupture of the aryl ether bond and the phenolic hydroxyl group in lignin. The influence of the acid roots on the secondary cracking reaction of LG was in the order of ${\rm{HCO}}_3^- $>${\rm{CO}}_3^{2-} $>AC>${\rm{PO}}_4^{3-} $>Cl>${\rm{NO}}_3^- $>${\rm{SO}}_4^{2-} $, while the influence of acid roots on the rupture of the aryl ether bond and the phenolic hydroxyl group was in the order of ${\rm{CO}}_3^{2-} $>Cl>${\rm{HCO}}_3^- $>${\rm{PO}}_4^{3-} $≈AC>${\rm{SO}}_4^{2-} $${\rm{NO}}_3^- $.
Catalytic pyrolysis of waste biomass to produce hydrogen-rich gas:Influence of catalyst performance
LI Xueqin, LIU Peng, LU Yan, WANG Zhiwei, WU Youqing, LEI Tingzhou
 doi: 10.19906/j.cnki.JFCT.2024011
Abstract(20) HTML(7) PDF 9088KB(2)
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Catalytic pyrolysis of waste biomass is a promising method for the production of hydrogen-rich gas. HZSM-5 carrier is the premise of ensuring the thermal stability and long life of catalytic materials, and plays a mechanical role in bearing the active component nickel(Ni). At the same time, aluminum ash, as an important waste in the production process of aluminum industry, is mainly composed of Al2O3 and a large number of heavy metal oxides such as Na2O, CaO, MgO, Fe2O3 and so on. In this study, aiming at the technical bottleneck problems such as the low performance of traditional HZSM-5 molecular sieve and the difficulty of resource utilization of aluminum ash, the active component nickel (Ni) and promoter iron (Fe) were combined with HZSM-5 molecular sieve by ultrasonic-assisted excessive impregnation to improve the yield of hydrogen-rich gas. Furthermore, waste aluminum ash (ASA) and HZSM-5 molecular sieve were used as co-carriers to prepare aluminum ash co-supported Ni-Fe catalyst with HZSM-5 molecular sieve, and it was used to enhance the process of hydrogen-rich gas production by the catalytic pyrolysis of biomass. The results showed that the heat transfer efficiency decreased with the increase of heating rate during pyrolysis of biomass. After compensation, the apparent kinetic parameters (E and A) of pyrolysis of different biomass were obtained. At the pyrolysis temperature of 700 ℃, Ni-Fe/HZSM-5 catalyst increases the yield of hydrogen-rich gas to 56.49% (about 230.59 mL/g), hydrogen yield to 63.12%, hydrogen production efficiency to 0.71%, and CO yield to 65.77 mL/g. Sufficient amount of Ni-Fe/HZSM-5 catalyst enhanced the pathway of hydrogen production by the catalytic pyrolysis of biomass, promoted the gasification reaction of carbon deposition, and played a dual role in increasing the yield of H2 and CO. The synergism between HZSM-5 and ASA carriers enhanced the reforming process of CH4 and CO2, inhibited the reverse water vapor shift reaction, obtained 53.37% and 41.56% gas and tar yields. At the same time, the gasification reaction of carbon deposition was also accelerated, reduced the char yield to 5.07%, and obtained the carbon deposition of 0.05 g/g. Ni-Fe/ASA@HZSM-5 has good thermal cracking ability and deoxidization ability, which is helpful to promote the formation of hydrogen-rich gas on HZSM-5 as a base catalyst. From the point of view of proximate analysis and chemical composition of biomass, the composition of different kinds of biomass varies greatly, and the product distribution of catalytic pyrolysis also has a great influence. The order of gas yield of pyrolysis of biomass catalyzed by Ni-Fe/HZSM-5 was PR (74.21%)>WSt (54.71%)>CR (53.5%)>MCh (52.47%)>WSh (52.10%)>CS (46.49%)., which provides theoretical support for the development of deep purification and efficient utilization of high temperature pyrolysis gas, and effectively guides the development of a new double catalytic bed for multi-stage catalytic reforming.
Theoretical study on the pyrolysis mechanism of the lignin dimer model compound catalyzed by alkaline earth metal ions Ca2+ and Mg2+
JIANG Xiaoyan, LI Yiming, TANG Li, DU Xiaojiao, DAI Lanhua, HU Bin
 doi: 10.1016/S1872-5813(24)60441-X
Abstract(5) HTML(10) PDF 1814KB(6)
Abstract:
It is essential to investigate the influence of alkaline earth metals on the pyrolysis mechanism and resulting products of lignin to enhance the efficient thermochemical conversion and utilization of lignin or biomass. In this study, the Density functional theory method was used to simulate the pyrolytic reaction pathways of a β–O–4 type lignin dimer model compound (1-methoxy-2-(4-methoxyphenethoxy)benzene, mc) affected by alkaline earth metal ions Ca2+ and Mg2+. The computational findings suggest that Ca2+ and Mg2+ tend to combine with the oxygen atom at the Cβ position and the oxygen atom on the methoxy group of the lignin dimer model compound, forming stable complexes that modify the bond lengths of the Cα–Cβ and Cβ–O bonds and affect their pyrolysis energy barriers. During the catalytic pyrolysis process, the presence of Ca2+ and Mg2+ can promote the concerted decomposition reaction, leading to increased production of products like 1-methoxy-4-vinylbenzene, 2-methoxyphenol and catechol. Meanwhile, they can suppress homolytic cleavage reactions of the Cβ–O and Cα–Cβ bonds, thereby hindering the formation of other products such as 1-ethyl-4-methoxybenzene and 2-hydroxybenzaldehyde.
review
Recent advances in the preparation of high-value-added chemicals by catalytic hydrogenolysis of lignin
LIU Juping, TANG Ziyue, CHEN Yingquan, WANG Xianhua, CHEN Hanping, YANG Yang, YANG Haiping
 doi: 10.19906/j.cnki.JFCT.2024009
Abstract(34) HTML(3) PDF 7951KB(9)
Abstract:
The development and utilization of renewable biomass resources is an effective way to achieve CO2 reduction. Biomass, on the other hand, has a complex structure with low overall reactivity and utilization. Lignin is the only renewable aromatic polymer with high energy density in nature, and its conversion and utilization have attracted much attention worldwide. However, the complexity of the lignin structure, the uncertainty of the linkages, the stability of the side-chain connections, and the inevitable recondensation of the reactive fragments make the depolymerization of lignin into biofuels or aromatic chemicals a formidable challenge. Catalytic hydrogenolysis technology converts lignin into highly selective, high-yield phenolic monomers with high heating value, low oxygen content, and high carbon utilization of the product. However, the mechanism of the conversion between products and structures remains unclear with respect to the directed bond shearing during the catalytic depolymerization of lignin. In this paper, in view of the latest research progress on the catalytic hydrogenolysis of lignin for the production of high-value chemicals. We focus on the catalytic hydrogenolysis of lignin to summarize the coupling correlation between the catalysts and their products of high-value chemicals and focus on the influence of different catalyst systems on the process mechanism of lignin depolymerization products. For metal-based catalysts in particular, a detailed review of recent advances in the effects of noble metal-based catalysts, transition metal-based catalysts, hydrotalcite catalysts, and metal-organic framework catalysts on product distribution is presented. And further summarized the problems and conversion mechanisms of different catalysts. Meanwhile, the solvent in the lignin catalytic hydrogenolysis cracking process is the key to promote lignin dissolution, accelerating the heat and mass transfer, and promoting the homogeneous dispersion of reactants and catalysts in the reactor. In this paper, the main solvents for lignin liquefaction, such as water, alcohol, and new solvent systems, are reviewed for their depolymerization impact on lignin. And further, outline the effect of the solvent system on the properties of lignin conversion products. Nevertheless, there are still many difficulties in the catalytic hydrogenolysis of lignin for the preparation of high-value chemicals. The complexity of the macromolecular structure of lignin, the directed depolymerization of the C−O and C−C structures is still difficult, and the preparation of efficient catalysts as well as the mechanism of directional regulation of the products are still to be further investigated. Due to the insolubility of lignin, no solvent system that can completely dissolve lignin has been found yet; secondly, the research on the solvent effect is still only in the preliminary exploration stage. Novel technology for favorable conversion of lignin is still only at the stage of laboratory research. And the efficient conversion of renewable lignin into valuable chemicals and fuels is of great significance in solving the energy crisis and slowing down global warming, and at the same time, it will help our country to realize the energy-dependence transition from oil to renewable biomass. So finally, the opportunities and challenges facing the field are summarized and outlooked, providing a theoretical reference for efficient targeted conversion and high-value utilization of lignin.
A research paper
Study on copper-based oxygen carrier catalytic power plant flue gas deoxidation
SIMA Hao, WANG Xuefeng, DENG Cunbao
 doi: 10.1016/S1872-5813(23)60409-8
Abstract(36) HTML(17) PDF 8759KB(7)
Abstract:
The main components of power plant flue gas are N2, CO2 and part O2. Injecting power plant flue gas into mine goaf can achieve CO2 storage and replace nitrogen injection to prevent spontaneous combustion of left coal. However, O2 in flue gas is one of the factors causing spontaneous combustion of left coal. Therefore, it is urgent to develop an economical and effective catalyst to remove O2 from power plant flue gas. In this study, four types of copper-based catalysts were prepared using a controllable modulating carrier and loading capacity through co-precipitation method. Additionally, a series of xCuO/CeO2 catalystswere synthesized. The catalysts were characterized using BET analysis, XRD analysis, ICP analysis, TEM analysis, H2-TPR and XPS analysis to establish a structure-activity relationship between catalyst structure and deoxidation performance for catalytic power plant flue gases. The results showed that the addition of CeO2 improved the dispersion of CuO, increased the oxygen vacancy of the catalyst, and improved the activity and reduction oxidation performance of the catalyst. Moreover, the synergistic effect of Cu-Ce interface structure promoted the reduction oxidation process, showing good activity and cycle stability. Among xCuO/CeO2 catalysts, 30CuO/CeO2 showed the best catalytic deoxidation performance due to its smallest CuO particle size, highest dispersion and highest oxygen vacancy concentration. The results of this study provide a reference for the development of low cost, recyclable, high activity and high stability deoxidation catalysts.
A research paper
Mechanism of catalytic decomposition of NO by Cu-ZSM-5
ZHANG Huan, LIU Liang, SHI Yilin, QIAO Xiaolei, JIN Yan
 doi: 10.1016/S1872-5813(23)60408-6
Abstract(21) HTML(10) PDF 5389KB(2)
Abstract:
Catalytic decomposition of NO by Cu-ZSM-5 has potential application. In order to reveal the catalytic decomposition mechanism of NO over Cu-ZSM-5, the adsorption of NO over short-range Cu+ pairs in Cu-ZSM-5 was simulated based on the density functional theory, and proposed reaction pathways for the catalytic decomposition of NO assisted by by-products N2O and NO2. The calculation results show that the double nuclear copper-oxygen species is an important active center of Cu-based catalyst. During the catalytic decomposition of NO, the highest activation energy (171.39 kJ/mol) was required for the decomposition of the by-product NO2 on the double nuclear copper-oxygen species, and an activation energy base of 86.92 kJ/mol was required for the decomposition of N2O, suggesting that the decomposition of NO2 in the active site is more difficult than the decomposition of N2O. The resolution of N2 and O2 absorbed 28.43 and 100.78 kJ/mol of energy, respectively. And the rate determining step was O2 desorption. NO acts both as a reactant and a key reductant for the redox cycle achieved in the active center of Cu-ZSM-5 during the catalytic process.
A research paper
Hydrothermal flowthrough pretreatment of biomass and pyrolysis characteristics of its residual solid
LIU Tianlong, LI Qi, LI Zhonghong, YANG Peiyan, PANG Xinbo, HUANG Xin, ZHAO Xiaoyan, Cao Jingpei
 doi: 10.19906/j.cnki.JFCT.2023082
Abstract(50) HTML(21) PDF 4267KB(15)
Abstract:
The sophisticated multi-components and densed cross-link chemical structures of lignocellulosic biomass are important bottlenecks restricting its value-added utilization. The pre-fractionation of lignocellulose components is of great significance for the fractional conversion of biomass. The present study subjected rice husk (RH) to hydrothermal treatment in a flowthrough mode and investigated the effects of hydrothermal temperature and water flowrate on the decomposition rate of RH, chemical components of residual solids and their pyrolysis characteristics. It is shown that the decomposition of RH under hydrothermal conditions conformed well to the unreacted shrinking core model with phase boundary reactions rate-controlling. The pretreatment at 180 ℃ removed 95% alkali and alkaline-earth metallic species, 92% hemicellulose and 59% lignin from RH and selectively retained most of the cellulose components. As a result of the pretreatment, the relative content of anhydrosugar (mainly levoglucosan) from pyrolysis of RH at a curie-point temperature of 445 ℃ was increased from 9.9% up to 48.2% (area%) .
A research paper
Multi-site Co2p catalyst derived from soybean biomass for dehydrogenation of formic acid
WANG Bixi, LIU Zeyu, WU Yabei, YANG Yanyan, YANG Song, WANG Xun, YE Zi, DONG Hongliang, ZHU Feng, YU Huanhuan, LÜ Yingying, YU Zhongliang
 doi: 10.1016/S1872-5813(23)60410-4
Abstract(18) HTML(10) PDF 5073KB(3)
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Formic acid (FA) is a sustainable liquid organic hydrogen carrier and the catalyst for hydrogen production from FA has received significant attention. However, the development of efficient non-noble metal catalysts still remains challenges. In this work, we provide a technologically rather simple and environmental-friendly strategy to synthesize Co2P catalyst for dehydrogenation of FA by pyrolyzing soybean powder and cobalt salt. The K-containing solid bases in catalyst could act as Lewis acid sites for the HCOO intermediate adsorption while the self-doped N could act as Lewis base sites to enhance the H+ adsorption. The P contained in soybean could combine with Co to form Co2P for H−C bond cleavage of HCOO. At a Co(NO3)2·6H2O/soybean mass ratio of 1∶15, the as prepared Co2P catalyst demonstrated a gas production rate of 237.47 mL/(g·h) and a good stability. This study provides a novel strategy to develop non-noble metal heterogeneous catalysts for FA dehydrogenation.
A research paper
Study on the antioxidant property of calixarene in high density hydrocarbon fuel JP-10
YANG Yuxin, LEI Quan, CHEN Xinyang, DAI Yitong, FANG Wenjun, GUO Yongsheng
 doi: 10.19906/j.cnki.JFCT.2024002
Abstract(22) HTML(15) PDF 1351KB(4)
Abstract:
Since the 21st century, hypersonic flight technology has attracted much attention. When the aircraft is flying at a high Mach number, a large amount of aerodynamic heat is generated between the air and the aircraft due to friction, resulting in a rapid increase in the temperature of the aircraft subsystem, exceeding the range that the material can withstand, affecting the flight safety of the aircraft. In order to meet the thermal management needs, an integrated cooling approach combining heat transfer and combustion has been introduced. This method utilizes hydrocarbon fuels both as propellants and coolants to absorb the excess heat from the aircraft's high-temperature components, thereby enhancing energy efficiency and managing the thermal conditions of high-speed aircraft. Fuels that satisfy this concept are called endothermic hydrocarbon fuels. However, these fuels are prone to oxidation due to heat, oxygen, and catalysis during storage and use, leading to the formation of insoluble gums and degraded performance, which may even clog the fuel system, endangering flight safety. Thus, suppressing the oxidation process of high-density endothermic hydrocarbon fuels is crucial for fuel storage and usage. Common methods to improve the oxidation stability of fuels include surface treatment, fuel deoxidation, and the addition of antioxidants to the fuel. Among these methods, adding antioxidants is one of the most commonly used methods. Hindered phenolic antioxidants are favored for their cost-effectiveness, but small molecule antioxidants like tert-butylhydroquinone (TBHQ) and butylated hydroxytoluene (BHT) suffer from sublimation at high temperatures, resulting in poor oxidation resistance. Conversely, commercial macromolecular antioxidants, such as L-1010 and L-1076, fall short of the antioxidant needs of hydrocarbon fuels due to their limited properties. In order to make up for the shortage of commercial hindered phenolic antioxidants, researchers have focused on the development of new antioxidants with high temperature resistance and significant antioxidant effect. Calixarenes, with their structural features of hindered phenols, are seen as potential antioxidants, Especially, the calixarene synthesized with resorcinol as monomer has high phenolic hydroxyl content, which can quench the oxygen free radicals produced in the process of fuel oxidation by providing more abundant hydrogen free radicals, thus has better oxidation resistance. However, reports on using calixarenes for enhancing the oxidation resistance of high-density hydrocarbon fuels remain scarce. In this paper, C-undecylcalix[4]resorcinarene(C11-C[4]R) was synthesized by using resorcinol and dodecanal, and its oxidation resistance in high-density hydrocarbon fuel JP-10 was investigated.and compared with several commercial antioxidants:2,6-di-tert-butyl-4-methylphenol, tetra [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester and β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester. The results of high pressure differential scanning calorimeter (PDSC) showed that the effect of four antioxidants ranked as follows: C11-C[4]R > BHT > L-1010 > L-1076. In addition, the oxidation consumption process of four hindered phenolic antioxidants in JP-10 was analyzed from the perspective of kinetics, and the oxidation consumption rate constant was calculated. The results showed that the reaction rate constant of C11-C [ 4 ] was the smallest and the consumption rate in JP-10 was the slowest. Besides, the oxidation reaction process of JP-10 was also studied using the static kettle accelerated oxidation method. Based on these findings, a potential antioxidant mechanism of C11-C[4]R in JP-10 was proposed.
A research paper
Study on gas phase reaction mechanism of HCN and H2/H2O based on density functional theory
SUN Mingzhe, XU Jianliang, HOU Qiushi, DAI Zhenghua, WANG Fuchen
 doi: 10.19906/j.cnki.JFCT.2024004
Abstract(24) HTML(4) PDF 9275KB(5)
Abstract:
HCN is a highly toxic substance that can enter the human body through the skin and respiratory system, and in severe cases, cause death. HCN can achieve partial conversion under high-temperature gasification conditions, mainly by reacting with H2 and H2O. In order to further explore the micro reaction mechanism of HCN with H2 and H2O during gasification, and to investigate the effects of temperature and pressure changes on the reaction, this paper uses quantum chemical simulation methods to study the reaction path, reaction thermodynamics, and kinetics of the above reactions, and quantitatively analyzes the changes in thermodynamic parameters and reaction rate constants with temperature, fitting the Arrhenius equation related to the reaction. Calculate the distribution of Fukui functions for various reactants and intermediates in the reaction process of HCN with H2 and H2O using Multiwfn, and speculate on possible reaction pathways. The transition state search and single point energy calculation of the reaction process between HCN and H2 and H2O were carried out using Gaussian & Gaussian View. Similarly, using the wave function program Multiwfn to calculate the Mayer bond order. The analysis of the bond order curve during the reaction process can reveal the changes in the strength of chemical bonds and the situation of bond formation and breaking. Use the Shermo program to calculate the thermodynamic parameters of each stagnation point at different temperatures, including enthalpy, entropy, Gibbs free energy, and partition function. Finally, the KiSThelP program was used to calculate the reaction rate constants for each step of the reaction based on classical transition state theory at different temperatures. The results show that the relatively optimal path for the reaction between HCN and H2 is as follows: three H2 molecules are added in three steps on C≡N to obtain the product CH4+NH3; The relatively optimal path for the reaction between HCN and H2O is as follows: H2O molecules attack C atoms, and the H of O and C atoms are transferred to N atoms to obtain the product CO+NH3. The first step of reaction between HCN and H2 is R1→IM1 which is below 534K with ΔG<0. After exceeding this temperature, ΔG>0 becomes a reverse spontaneous reaction. It can be considered that an increase in temperature is not conducive to the electrophilic addition reaction of the first H2 on C≡N. The second step is IM1→IM2, with ΔG below 1103K less than 0 and above greater than 0, indicates that the spontaneity of the second step H2 addition reaction is inhibited as the temperature gradually increases. The third step is IM2→P1. Within the set temperature range, its ΔG is always less than 0, and the reaction can always proceed spontaneously. The ΔG of the first step reaction R2→IM5 in Path 3 is only less than 0 at room temperature, indicating that this step is difficult to occur spontaneously at high temperatures. Path 3 second step reaction IM5→IM6 ΔG is always less than 0 within the set temperature range. The third step of the reaction is IM6→P2, and the temperature of ΔG below 958 K is greater than 0, making it difficult to occur spontaneously. The research results on changes in pressure and free energy show that pressure can increase the upper temperature limit for spontaneous reaction.The reaction rates of HCN with H2 and HCN with H2O are relatively fast at high temperatures. The rate determining steps for Path 1 and Path 3 at high temperatures are R1 → IM1, R2 → IM5, respectively. The rate constants for the two reaction steps above 1473 K are 9.57×10−4 mol/(L·s) and 1.71 mol/(L·s), respectively. The pre-exponential factors for these two reactions were calculated to be 4.45×109s−1 and 4.68×108s−1, and the activation energies were 357.62 and 239.30 kJ/mol, respectively.
review
Research progress of SCR medium temperature denitrification catalyst for cement industry
HAN Yuxuan, ZHOU Yu, TAN Chenchen, WU Peng, DING Shipeng, SHEN Kai, ZHANG Yaping
 doi: 10.19906/j.cnki.JFCT.2023084
Abstract(44) HTML(28) PDF 10313KB(6)
Abstract:
Selective catalytic reduction (SCR) technology has been widely used in the denitrification of cement industry, in which a relatively mature system has been formed in the high temperature(280–350 ℃) section, but there is still a breakthrough in the middle temperature zone. Focusing on medium temperature catalysts, this paper reviewed the progress of Mn, Ce and V catalysts, and analyzed the doping of Sm, Nb, Ho, Sb, La, Mo and Pr to improve the performance of catalysts. Combined with the characteristics of the high content of SO2, H2O and alkali metal in cement kiln smoke, the causes of catalyst poisoning were analyzed, summarize the way to resist sulfur poisoning, water poisoning, and alkali metal poisoning. The research prospect of SCR medium temperature denitration catalyst in cement industry is prospected.
A research paper
Preparation of Co/Zr/Al2O3-Pt/ZSM-5 catalysts for syngas to liquid fuels
LI Hang, ZHANG Yuhua, XIANG Rong, AI Xinyan, YAN Haoyu, LIU Chengchao, LI Jinlin
 doi: 10.19906/j.cnki.JFCT.2023087
Abstract(64) HTML(16) PDF 27923KB(14)
Abstract:
The Co catalysts exhibit high catalytic activity and low water gas shift activity, as well as excellent chain growth ability and low by-product selectivity for Fischer-Tropsch synthesis. The performance of the Co catalyst is influenced by several factors, including its structural composition and physical and chemical properties. The traditional cobalt Fischer-Tropsch catalyst follows the ASF distribution, resulting in a wide range of hydrocarbon products. This makes it difficult to achieve high selectivity for liquid hydrocarbons. Due to the presence of a large number of acidic sites on the surface of zeolite, it has excellent catalytic performance for hydrocracking. The integration of zeolite molecular sieves with Fischer-Tropsch catalysts to form a multi-component catalyst can significantly improve product selectivity, optimize liquid hydrocarbon yields and bypass conventional wax treatment steps. In this study, the catalysts Co/Al2O3, Co/Zr/Al2O3 and Co/Zr/Al2O3-Pt/ZSM-5 were prepared by ultrasonic dispersion method, and the effects of Zr promoter modification and multicomponent coupling catalyst on the activity and product selectivity of Fischer-Tropsch synthesis were investigated. In Co/Al2O3, Co/Zr/Al2O3 and Co/Zr/Al2O3-Pt/ZSM-5 catalysts, the Co species are uniformly dispersed on the support surface and have similar particle sizes. Pt and Zr were uniformly dispersed in the catalyst, Zr was mainly dispersed on the surface of Al2O3 supports, and Pt was mainly dispersed on the surface of ZSM-5 molecular sieve. The reduction of Co species was promoted by Zr-modified alumina. With the addition of Pt/ZSM-5 catalyst, the adsorbed hydrogen is more easily dissociated and converted into active hydrogen, further promoting the reduction of Co species. The catalytic performance of Fischer-Tropsch synthesis was evaluated. Compared with Co/Al2O3 catalyst, the selectivity of C12+ heavy hydrocarbon products on Co/Zr/Al2O3 catalyst increased from 28.2% to 38.1%, with a corresponding decrease in CH4, C2−C4 and C5−C11 products, indicating that Zr promoter promoted the generation of heavy hydrocarbon products. Coupled with Pt/ZSM-5 catalyst, the Co/Zr/Al2O3-Pt/ZSM-5 catalyst showed low CH4 selectivity (10.0%) and C2−C4 selectivity (15.0%), while the selectivity of C5−C11 liquid hydrocarbon products increased from 32.1% to 45.9%, the selectivity of heavy hydrocarbon products (C12+) decreased from 38.1% to 29.1%. Compared to Co/Zr/Al2O3, the TOF and CTY of Co/Zr/Al2O3-Pt/ZSM-5 catalysts are increased by 212.6% and 62.7%, respectively. The improvement in catalytic activity was mainly due to the addition of Zr promoter and Pt/ZSM-5 catalyst, which promoted the reduction of Co species. Under the synergistic effect of Zr promoter and Pt/ZSM-5 catalyst, Zr promoter promotes the formation of C12+ heavy hydrocarbons, while Pt/ZSM-5 catalyst promotes the hydrocracking of heavy hydrocarbons to C5−C11 liquid hydrocarbons, thereby improving the selectivity of Co/Zr/Al2O3-Pt/ZSM-5 catalyst for C5−C11 liquid hydrocarbons. In this study, a functional catalyst was constructed by coupling Fischer-Tropsch synthesis catalyst and hydrocracking catalyst at nanoscale, which achieved high selectivity of C5−C11 liquid hydrocarbon and low selectivity of CH4 and C2−C4 products, which provided a reference for the design and implementation of catalysts with high selectivity for liquid hydrocarbons.
A research paper
Preparation of Ni0.6Cu0.4O/NC catalyst and its catalytic performance for hydrogen production from hydrolysis of ammonia borane
LI Rong, ZUO Youhua, HUA Junfeng, HAO Siyu, XU Lixin, YE Mingfu, WAN Chao
 doi: 10.1016/S1872-5813(24)60436-6
Abstract(16) HTML(4) PDF 2336KB(5)
Abstract:
Ammonia borane (NH3BH3, AB) is an ideal feedstock for hydrogen production with high hydrogen storage capacity. In this paper, a nitrogen-containing carbon material (Ni0.6Cu0.4O/NC) catalyst was prepared by high-temperature carbonization of Ni/Cu-ZIF precursor under nitrogen atmosphere, and the microstructure as well as the composition of the prepared catalyst were investigated by various characterization methods. In addition, the catalytic performance of the catalyst and the variation rule were investigated by the controlled variable method. The results showed that the activation energy (Ea) of Ni0.6Cu0.4O/NC catalyzed hydrolysis of AB for hydrogen production was 56.8 kJ∙mol−1, and the TOF value was as high as 1572.2 h−1. The rate of hydrogen production from AB hydrolysis catalyzed by this catalyst could be approximated as a zero-order reaction with respect to the concentration of AB itself, and a one-order reaction with respect to the amount of catalyst. The catalyst still maintained good catalytic activity after ten cycles, indicating its good stability.
A research paper
Preparation and oxidation desulfurization performance of Zirconium oxychloride based ternary deep eutectic solvent
WANG Tianbo, LI Xiuping, ZHAO Rongxiang
 doi: 10.19906/j.cnki.JFCT.2023085
Abstract(46) HTML(14) PDF 2223KB(8)
Abstract:
A zirconium oxychloride based ternary deep eutectic solvent (DES) was prepared by simply heating mixture of ethylene glycol, p-toluenesulfonic acid and octahydrate zirconium oxychloride. The successful synthesis of deep eutectic solvents was verified using Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectroscopy (1H NMR). The acidity and viscosity were tested using UV-visible absorption spectroscopy and rotary viscometer, respectively. The extraction- oxidation desulfurization system was composed of hydrogen peroxide as the oxidant, deep eutectic solvent as the extractant and catalyst. The effects of the composition of the deep eutectic solvent, reaction temperature, oxygen sulfur ratio, solvent oil ratio, and different sulfides on the desulfurization rate were investigated. The experimental results showed that the desulfurization rates of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT) simulated oil were 100%, 92.2%, and 60%, respectively, under the optimal reaction conditions of a molar ratio of 1:10:10 between zirconium oxychloride, ethylene glycol, and p-benzenesulfonic acid components, 50 ℃, a solvent oil ratio of 1∶5, and an oxygen sulfur ratio of 8. After repeated use of the deep eutectic solvent for 5 times, the desulfurization rate could still reach 96.2%. The mechanism of oxidative desulfurization was explored.
Soluble conversion of Zhaotong lignite by ammonolysis and the occurrence forms of oxygen and nitrogen in soluble portion
REN Yuyao, ZHOU Guoli, LIU Haojie, TENG Daoguang, CAO Yijun, XING Baolin, LI Peng
 doi: 10.19906/j.cnki.JFCT.2023088
Abstract(21) HTML(9) PDF 6126KB(2)
Abstract:
Lignite is of high carbon content, rich in oxygen and nitrogen, and other heteroatoms, thereby is treated as an important raw material for the preparation of carbon materials. However, the preparation of carbon materials from lignite is faced with many challenges, due to the low soluble organic carbon content and the irregular distribution of heteroatoms. Therefore, it is necessary to achieve the soluble transformation of lignite. In this investigation, ammonia was applied to achieve the solubilization of Zhaotong lignite, and also the regulation of oxygen and nitrogen in soluble portion from lignite under mild conditions. As a result, Zhaotong lignite exhibits efficient thermal dissolution with a soluble portion yield of 76.66%, at the condition of ammonium concentration of 15%, temperature of 160 ℃, and reaction time of 3 h. Based on the characterization and analysis of soluble portion, the macromolecular structure of coal was changed by ammonolysis, mainly displayed as the replacement of hydroxyl group by amino group, or produce organic nitrogen by direct reaction with some carboxyl group and carbonyl group. By contrast, the occurrence forms of nitrogen elements in raw coal are mainly quaternary nitrogen and pyrrole nitrogen, while the occurrence forms of nitrogen elements in soluble matter are mainly amino nitrogen and pyridine nitrogen, indicating that amino or amide groups are formed during the thermal dissolution of lignite.
Highly effective MFe2O4 (M=Zn, Mg, Cu and Mn) spinel catalysts for Fischer-Tropsch synthesis
WANG Chao, CHEN Jiangang, ZHU Huaqing, ZHANG Wenshao, BAI Hongbin, ZHANG Juan
 doi: 10.1016/S1872-5813(23)60406-2
Abstract(59) HTML(18) PDF 4779KB(22)
Abstract:
A series of spinel catalysts, including ZnFe2O4, MgFe2O4, CuFe2O4, and MnFe2O4, were prepared and applied to the Fischer-Tropsch synthesis (FTS). Zn, Mg, Cu and Mn easily form spinels with Fe. Among them, Zn and Mg can significantly maintain the spinel structure during the pretreatment and reaction, resulting in a low CO conversion. Cu and Mn are beneficial to the formation of iron carbide during the reaction, resulting in an apparent influence on FTS performance. ZnFe2O4 has little effect on the hydrocarbon distribution and the olefin/paraffin (O/P) ratio of C2−C4. MgFe2O4 exhibits low selectivity for C5+ hydrocarbons, and the selectivity of $ {\mathrm{C}}_2^=-{\mathrm{C}}_4^=\;$ and the O/P ratio of C2−C4 in the product are increased due to the alkaline effect of Mg. Cu can promote the carbonization of the catalyst, so that CuFe2O4 has higher activity. Meanwhile, CuFe2O4 can significantly improve the selectivity of C5+ hydrocarbons. Moreover, Cu can promote the dissociation and activation of H2, which is beneficial to the secondary hydrogenation of olefins, thereby reducing the selectivity of $ {\mathrm{C}}_2^=-{\mathrm{C}}_4^=\;$ and the O/P ratio of C2−C4. Mn promotes carbonization during the reaction, but MnFe2O4 has little effect on the chain growth of hydrocarbon. However, Mn can promote the generation of a certain amount of ε-Fe2C, which may explain the higher selectivity of $ {\mathrm{C}}_2^=-{\mathrm{C}}_4^=\;$ and the O/P ratio of C2−C4 for MnFe2O4. All spinel catalysts exhibit low CO2 selectivity, which meets the current green environmental protection requirements.
A research paper
Mechanism of heterogeneous reduction of NO by graphite-supported single-atom Fe catalyst: DFT study
ZHAO Yan, LI Xiang, HUANG Jinkai, LI Xianchun, ZHU Yaming, WANG Huanran
 doi: 10.1016/S1872-5813(23)60407-4
Abstract(32) HTML(21) PDF 5095KB(6)
Abstract:
The micro-mechanism of NO heterogeneous reduction by graphite carbon supported single atom iron catalyst (Fe/G) was studied using density functional theory (DFT), transition state theory (TST), and the reason of catalyst deactivation was analyzed. The results showed that the NO reduction reaction based on E-R mechanism undergoes four stages of N2O formation and release, N2 formation and release. However, the NO reduction reaction based on L-H mechanism undergoes two stages of N2 formation and release. Based on the E-R mechanism, the energy barrier of NO reduction rate-controlled step in which NO molecule is adsorbed on Fe atom with N,O-down structure is only 15.5 kJ/mol, which is lower than that of other paths. Through energy barrier analysis, the energy barrier value of reactive oxygen species reduced was higher than that formation of N2. Reactive oxygen species remaining on the surface of Fe atom after NO decomposition inhibited the adsorption and reduction of NO, and the absence of active site leads to the deactivation of catalyst. The presence of single-atom Fe promoted the NO reduction reaction. Through kinetic analysis, with the increase of reaction temperature, the NO reduction rate increases more significantly than the reactive oxygen transfer rate.
A research paper
Electrocatalyst hydrogenation of lignol-derived compounds: Conversion regularity and product selectivity
WEI Dening, TANG Hongbiao, YANG Gaixiu, YANG Juntao, LI Ning, CHEN Guanyi, CHEN Chunxiang, FENG Zhijie
 doi: 10.1016/S1872-5813(23)60405-0
Abstract(42) HTML(17) PDF 1138KB(14)
Abstract:
Phenolic derivatives, crucial components of bio-oil, require thorough understanding of their electrocatalytic hydrogenation (ECH) properties for efficient bio-oil utilization. This study investigated guaiacol, a representative phenolic derivative in bio-oil, focusing on its ECH mechanism, conversion, and product selectivity under varied conditions (temperature: 40−80 °C, perchloric acid concentration: 0.2−1.0 mol/L, current intensity: ((−10)−150 mA). Additionally, this study also explored the influence of intermediate products (2-methoxycyclohexanone and cyclohexanone) on both the conversion rate and the selectivity of the products. The experiment had revealed that guaiacol's ECH conversion rate improved with higher temperature and current intensity, whereas an increase in perchloric acid concentration negatively affected the conversion. Significantly, the presence of intermediate products, especially 2-methoxycyclohexanone, markedly enhanced the ECH conversion of guaiacol. Investigating further into the ECH mechanism of other phenolic derivatives, including phenol, pyrocatechol, guaiacol eugenol, and vanillin, as well as their combination, revealed a trend where conversion rates inversely correlated with the complexity of the functional groups on the benzene ring. Specifically, phenol, with its simpler structure, showed the highest conversion rate at 89.34%, in stark contrast to vanillin which, owing to its more complex structure, exhibited the lowest at 46.79%. In our multi-component mixture studies, it was observed that synergistic and competitive interactions significantly alter ECH conversion rates, with some mixtures showing enhanced conversion rate indicative of synergistic effects.
review
Recent advances in preparing biomass-based 2,5-bis(hydroxymethyl)furan by catalytic transfer hydrogenation
LI Wei, GONG Honghui, SHI Xianlei
 doi: 10.1016/S1872-5813(23)60403-7
Abstract(151) HTML(58) PDF 36414KB(57)
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Biomass-based 2,5-bis(hydroxymethyl)furan (BHMF) is one of the important high value-added chemicals, which can be prepared from inexpensive and renewable carbohydrates through the way of catalytic conversion and selective hydrogenation, and as a widely used chemical intermediate and fuel precursor, it has unique advantages in improving the performance of traditional polyesters and synthesizing new biodegradable bio-based polyesters. In recent years, the research on the production of high value-added chemicals such as BHMF from carbohydrate has been attracting much attention from both academia and industry. However, cleanliness, high efficiency, high selectivity and low-cost remain key challenges in this area, especially for practical applications. In the process of BHMF production, the traditional hydrogenation method consumed a large amount of high-grade energy of hydrogen, and an excessive investment in infrastructure would be generated due to the security risks of higher pressure of hydrogen. On account of the advantages of catalytic transfer hydrogenation, the advances in selective hydrogenation to prepare BHMF using formic acid, alcohols and other types of hydrogen donors by the approach of catalytic transfer hydrogenation is systematically discussed in this review. In view of the features and problems of different types of hydrogen donors, catalysts and reaction processes during the catalytic transfer hydrogenation process, the effects of reaction conditions and process intensifications on the selectivity and yield of BHMF, and the merits and demerits of the reaction system were all investigated. On this basis, the future directions of new catalytic systems for preparation of BHMF by transfer hydrogenation is proposed, and the cleaner, more efficient and essential safety technologies for the production of BHMF is predicted, which will provide some scientific reference for the research and development of related catalytic systems in biomass conversion.
A research paper
Enhanced electro-catalytic activity of TNTs/SnO2-Sb electrode through the effect mechanism of TNTs architecture
YANG Lisha, GUO Yanming
 doi: 10.1016/S1872-5813(23)60390-1
Abstract(69) HTML(22) PDF 13063KB(7)
Abstract:
The TiO2 nanotubes arrays/SnO2-Sb (TNTs/SnO2-Sb) electrode is successfully fabricated using the solvothermal synthesis technique. Various architectures of TNTs are constructed by varying the anodization voltage and time, aiming to investigate their impact on the structural and electrochemical properties of the SnO2-Sb electrode. The anodization voltage is identified as the primary influencing factor on the morphology and surface hydrophilia of TNTs arrays, which is evidenced by scanning electron microscopy (SEM) and contact angle testing. In contrast, the effect of anodization time is relatively small. SEM, X-ray diffraction (XRD), linear sweep voltammograms (LSV), and electrochemical impedance spectroscopy (EIS) results indicat that the morphology and crystal size of the catalytic coating, as well as the oxygen evolution potential of the electrode, are influenced by the pore size of TNTs arrays. The influencing mechanism of enhanced electrochemical activity by adjusting the architecture of TNTs arrays is investigated using X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and Hydroxyl radicals (·OH) generation test. The results reveal a higher concentration of oxygen vacancies on the sample with a compact and smaller particle coating, indicating the presence of more adsorbed oxygen species. Consequently, this enhancs the generation capacity of active radicals for organic matter degradation. The electrode featuring TNTs arrays with a length of 950 nm and a pore diameter of 100 nm exhibits the most effective remediation of phenol-containing wastewater, achieving approximately 92% ± 4.6% removal after a duration of 2 h.
Study on pyrolysis mechanism and kinetics of two of spiro [4,5] decane and spiro [5,6] dodecane
WANG Hongyan, SUN Xinyue, ZHOU Yurou, LIU Guozhu, WANG Yutong, CAO Jingpei
 doi: 10.19906/j.cnki.JFCT.2024001
Abstract(38) HTML(26) PDF 2109KB(11)
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Active cooling with high-energy-density liquid hydrocarbon fuel is one of promising techniques for the thermal protection of hypersonic aircrafts. To extend the flight range and increase the payload of volume-limited aerospace vehicles, high-energy-density liquid hydrocarbon fuel is directly used as an energetic additive or liquid propellant. Among them, biomass derived spiro-fuels, shown high density, low freezing point and high net heat of combustion due to compact molecular structures, are a kind of significant high-density fuel. The investigation of thermal pyrolysis of these spiro-fuels not only significantly improves the heat sink through the endothermic reaction, but also brings the new challenges of ignition and combustion of the cracked hydrocarbon fuel. The detailed theoretical calculations and molecular dynamics simulations of spiro [4,5] decane (C10H18) and spiro [5,6] dodecane (C12H22) initial pyrolysis were performed to explore the ring-size effect on the consumption of fuels and formation of primary products. The results show that the initial decomposition paths of the two spiro-fuels are very similar, mainly consumed by the open-ring isomerization via the unimolecular C−C dissociations of the six membered ring structure and H-abstractions by small radicals attacking the fuel parents. Due to the lower C−C and C−H bond dissociation energies caused by large tension of the seven membered ring structure, C12H22 may exhibit the lower initial decomposition temperature and higher reaction activity than C10H18. The differences of simultaneously formed fuel radicals during C10H18 and C12H22 initial pyrolysis further affect the formation pathways of C1−C7 small products, cycloalkenes and monocyclic aromatics. Among them, ethylene are the most important products. Due to the presence of inherent six membered rings in two spiro-fuels, monocyclic aromatics mainly originate from multi-step dehydrogenation reactions of fuel radicals, involving benzene, toluene, styrene and ethylbenzene. Notably, the size effect of spiro-ring in two fuels leads the obvious structural differences of the formation of chain hydrocarbons and cycloalkenes. For C10H18, a large number of penta- cycloalkenes may be generated, including cyclopentadiene, cyclopentene, fulvene, methylcyclopentadiene and methylcyclopentene, whereas the seven-membered ring structure of C12H22 may produce corresponding seven-membered products (cyclohexene and methylene cycloheptane). Moreover, the pyrolysis behaviors of these two spiro-fuels at 2000 K based on the ReaxFF molecular dynamics simulation were explored and show well consistent with the main products derived from DFT theoretical calculations. This work performs the DFT theoretical calculations and ReaxFF molecular dynamics simulation on the pyrolysis kinetic mechanisms of two representative high-density biomass fuels of spiro fuels, providing a possible initial pyrolysis path and laying a theoretical foundation for their practical application in engines. However, the complex working environment of the cooling channel poses more challenges to the actual pyrolysis process of the new high-density hydrocarbon fuels. In future research, pyrolysis experiments will be conducted under high temperature and high pressure conditions, and the detailed pyrolysis kinetics models with excellent predictive performance over a wide operating range will be constructed. At the same time, research will be conducted on the subsequent ignition and combustion process of the engine combustion chamber, exploring the impact mechanism of catalysts and fuel additives on this process, assisting in the practical application of fuel, improving fuel combustion efficiency, and effectively controlling pollutant emissions.
2024, 52(4): 1-6.  
Abstract(22) HTML(8) PDF 27169KB(9)
Abstract:
Research progress in catalysts for producing higher alcohols from bioethanol
WANG Wenwen, LU Yangyang, LI Zhiyu, ZHANG Yuchun, FU Peng
2024, 52(4): 461-480.   doi: 10.19906/j.cnki.JFCT.2023061
Abstract(199) HTML(83) PDF 22885KB(35)
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Compared with ethanol, higher alcohols have the advantages of high cetane number, high energy density, non corrosiveness to engine parts, immiscibility with water, good stability, and other advantages as fuel or fuel additive directly. The conversion of fermentation bioethanol into more valuable higher alcohols has attracted widespread attention. This paper reviewed the research progress of bioethanol to higher alcohols at home and abroad in recent years, including the research and development of metal oxides, hydroxyapatite (HAP) and supported metal catalysts. Finally, the current challenges and future research trends of bioethanol to higher alcohols are summarized and prospected, pointing out that the development of multifunctional catalysts is the focus of future research, and Aldol condensation is an effective strategy to further improve the conversion and selectivity of bioethanol to higher alcohols.
Review on the progress in the production of aromatic hydrocarbons by co-catalytic pyrolysis of biomass and plastics
HAN Dong, SUN Laizhi, CHEN Lei, YANG Shuangxia, LI Tianjin, XIE Xinping, XU Meirong, TANG Wendong, ZHAO Baofeng, SI Hongyu, HUA Dongliang
2024, 52(4): 481-495.   doi: 10.1016/S1872-5813(23)60401-3
Abstract(203) HTML(17) PDF 8989KB(69)
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Aromatic hydrocarbons, especially monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene (BTX), are important basic raw materials in the chemical industry, which are mainly derived from the catalytic reforming and thermal cracking of fossil fuels. The co-catalytic pyrolysis of biomass and plastic to produce aromatics has the advantages of high efficiency, environmental protection, low cost, and high selectivity. It can solve the problems of pyrolysis products such as high oxygen content, low aromatics yield, and low selectivity, which are caused by the characteristics of biomass rich in oxygen and poor in hydrogen. This article reviewed the research progress of co-catalytic pyrolysis of biomass and plastics to prepare aromatic compounds. Firstly, the types of raw materials for co-catalytic pyrolysis were introduced, and then the co-catalytic pyrolysis catalysts were emphasized. The reaction mechanisms of co-catalytic pyrolysis of biomass and plastics, such as the synthesis of dienes and hydrocarbon pool synergy were summarized. Finally, the future research focus and development direction of co-catalytic pyrolysis of biomass and plastics were proposed, which is developing the highly active and stable modified molecular sieve catalysts in order to improve the aromatics yield.
Research progress on CO2 catalytic conversion to value-added oxygenates
LI Yongheng, WU Chongchong, WANG Wenbo, XIN Jing, MI Xiaotong, YANG Guoming, SU Mengjun, ZHANG Siran, LI Hongbao
2024, 52(4): 496-511.   doi: 10.1016/S1872-5813(23)60404-9
Abstract(125) HTML(79) PDF 32400KB(46)
Abstract:
Chemical conversion of greenhouse gas CO2 into value-added oxygenates such as ethanol, acetic acid, propanal, propionic acid, butanol, etc. is challenging due to the complexity of C−C coupling and the uncontrollable bonding. In this review, recent research progresses on the synthesis of multi-carbon oxygenates from CO2 in fixed bed reactor are provided. Firstly, the reaction mechanisms of CO2 hydrogenation are summarized. Then, the potential catalysts applied in one-step or tandem CO2 hydrogenation, dry reforming with light hydrocarbons and hydroformylation were introduced over metal carbides, alkali metal modified single or binary metal catalysts such as Cu, Fe, Co, Rh, etc. The reaction mechanism over different catalysts were further elaborated. Finally, the problems and outlook are discussed.
Progress in design and application research of nitrogen carrier in chemical looping ammonia synthesis technology
GONG Zhouting, ZHANG Tan, LI Na, YANG Yanyan, LIU Shoujun, ZHENG Jie, YU Zhongliang, YANG Song
2024, 52(4): 512-524.   doi: 10.1016/S1872-5813(23)60397-4
Abstract(148) HTML(132) PDF 2841KB(46)
Abstract:
Ammonia is not only the main raw material of nitrogen fertilizer production, but also one of the energy carriers for the storage and conversion process of renewable energy. Therefore, the development of a mild ammonia synthesis technology has become an important research topic in recent years. The chemical looping ammonia synthesis technology decouples the ammonia synthesis reaction into several steps, including the nitrogen fixation and the ammonia release, which has the advantages of easy operation, mild reaction, and low energy consumption. As the key to the chemical looping ammonia synthesis, nitrogen carriers play the role of transferring energy and nitrogen species. However, the current low nitrogen fixation efficiency of nitrogen carriers severely limits the development of the chemical looping ammonia synthesis technology. Therefore, this article reviews the research on the design, preparation and application of nitrogen carriers for the chemical looping ammonia synthesis. Firstly, the design theory of nitrogen carrier is summarized; secondly, the current research status of nitrogen carrier is introduced, with a focus on how to improve the ammonia production rate of nitrogen carrier and the utilization rate of lattice nitrogen; finally, the opportunities and challenges of chemical looping ammonia synthesis technology are discussed, which provide a reference for the design and development of nitrogen carrier in the future.
TG-FTIR study on escape behavior of products from co-pyrolysis of coal and residuum
ZHOU Xiaodong, WU Hao, LIU Jingmei, HUANG Xueli, LIU Ting, ZHONG Mei, MA Fengyun
2024, 52(4): 525-535.   doi: 10.1016/S1872-5813(23)60393-7
Abstract(75) HTML(20) PDF 2198KB(13)
Abstract:
Coal and residuum are first co-pyrolyzed, and then hydrogenated into small molecule products during co-liquefaction. Therefore, clarifying influence of residuum on coal pyrolysis performance is an important thermochemical basis for regulating the process. The co-pyrolysis behavior of atmospheric residuum (AR) and Naomaohu coal (NMH) were investigated by TG, TG-FTIR and distributed activation energy model. The results showed that the peak temperature of the maximum rate of weight loss for the co-pyrolysis process was reduced by 7 °C compared with the theoretical value calculated by weighted average of AR and NMH pyrolysis alone, while the weight loss increased by 3%, the average activation energy decreased by 23.6 kJ/mol. In addition, the peak area of alkyl O-containing functional groups such as alcohols and ethers increased, whereas those of CO and CO2 decreased, suggesting that AR had a positive effect on NMH pyrolysis. Meanwhile, alkyl radicals from AR decomposition would combine with O-containing radicals generated from coal pyrolysis, thus resulting in a decrease of CO and CO2 by inhibiting breakage of carboxyl groups. This work will provide a scientific evaluation basis for revealing the influence of residuum on composition of coal liquefaction product during co-liquefaction.
Ni supported on Ti-doped SBA-15 catalyst for the selective hydrodeoxygenation conversion of lignin derivatives
ZHANG Hongke, WANG Weichen, XIANG Zhiyu, ZHOU Fangyuan, ZHU Wanbin, WANG Hongliang
2024, 52(4): 536-544.   doi: 10.1016/S1872-5813(23)60387-1
Abstract(109) HTML(19) PDF 9704KB(27)
Abstract:
The development of cost-effective and efficient catalysts plays a critical role in the selective hydrodeoxygenation of lignin derivatives for lignin valorization. Herein, we reported “metal-acid” bifunctional catalysts (Ni/Ti-SBA-15) consist of Ni nanoparticles highly dispersed on Ti doped SBA-15, which achieved 100% vanillin conversion and 96.46% selectivity of 2-methoxy-4-methylphenol (MMP) under mild conditions. Characterizations were employed to reveal the morphology and physicochemical properties of the catalysts. The results indicated that doping of Ti species not only increased the number of acidic sites but also promoted the high dispersion of Ni nanoparticles on the support. This research provides a novel concept for the synthesis of cost-effective and efficient catalysts, which contributes to the environmentally friendly and economical conversion of biomass derivatives.
Investigation on production of dimethyl carbonate from propylene carbonate and methanol on calcium cerium-based catalysts
GUO Jiong, YANG Jinhai, SHI Yilin, ZHAO Ning, XIAO Fukui, JIANG Xindong
2024, 52(4): 545-552.   doi: 10.1016/S1872-5813(23)60394-9
Abstract(93) HTML(11) PDF 2266KB(25)
Abstract:
Calcium cerium-based catalysts with different Ca:Ce molar ratio prepared by sol-gel method were characterized by XRD, N2 adsorption-desorption, FT-IR, XPS and CO2-TPD, and evaluated the activity for dimethyl carbonate (DMC) synthesis from propylene carbonate (PC) and methanol. The results indicated that more surface oxygen vacancies and more moderate basic sites are beneficial for methanol activation and thus leading to better catalytic activity. The PC conversion was 91.1% with DMC selectivity of 91.72% over 0.9CaCe under the reaction conditions-reaction time of 2 h, reaction temperature of 40 °C, methanol to propylene carbonate molar ratio of 15:1 and catalyst amount of 4% relative to the amount of PC.
A DFT study on the formation mechanism of side product 1,2-propanediol in the hydrogenation of dimethyl oxalate over copper catalyst
LUN Guodong, YAN Weiqi, ZHOU Jinghong, ZHU Yi’an, LI Wei
2024, 52(4): 553-564.   doi: 10.1016/S1872-5813(23)60399-8
Abstract(139) HTML(60) PDF 7308KB(27)
Abstract:
The costly separation of 1,2-propanediol (1,2-PDO), an unavoidable byproduct in the hydrogenation of dimethyl oxalate (DMO), significantly hampers the economic viability of coal-to-ethylene glycol (EG) technology. To address this challenge, the formation mechanism of the side product 1,2-PDO on the Cu(111) and Cu2O(111) surfaces during DMO hydrogenation was investigated, which focused on the active sites of copper catalyst and the dominant pathway through density functional theory calculation. The thermodynamics of each elementary step and the adsorption behavior of various species involved in the reaction network along with the local density of states and charge density difference were systematically analyzed. The results indicate that 1,2-PDO is generated more favorably on the Cu2O(111) surface than that on the Cu(111) surface, owing to the Lewis acid-base pairs, i.e. ${\rm{Cu}}_{{\rm{us}}}^{+} $ and ${\rm{O}}_{{\rm{suf}}}^- $ sites, present on the Cu2O(111) surface, which strengthens the binding of reactants, products, and reaction intermediates to the substrate. EG reacts primarily with methanol (MeOH) to form 1,2-PDO through Guerbet alcohol condensation reaction through three consecutive steps: alcohol dehydrogenation, aldol condensation, and unsaturated aldehyde hydrogenation. The ${\rm{O}}_{{\rm{suf}}}^- $ sites promote the dehydrogenation of alcohols into aldehydes, the generation of enolates during aldol condensation and the hydrogenation of unsaturated aldehydes, while the ${\rm{Cu}}_{{\rm{us}}}^{+} $ sites are responsible for the C–C coupling reaction. These findings may shed light on the mechanism of 1,2-PDO formation over Cu catalyst and provide fundamental knowledge for the development of more efficient catalysts and process optimization.
Preparation and properties of MnCu/Ce catalyst for CO preferential oxidation reaction
WU Jiaxin, HAN Jiao, LI Xue, XING Yue, ZHANG Caishun, LIU Daosheng, HOU Xiaoning, LIU Yajie, ZHANG Lei, GAO Zhixian
2024, 52(4): 565-576.   doi: 10.19906/j.cnki.JFCT.2023080
Abstract(90) HTML(36) PDF 2146KB(28)
Abstract:
The MnCu/Ce catalyst with a lower Cu content was prepared by co-impregnation method, and then was characterized by XRD, BET, H2-TPR, XPS and CO2-TPD. The effects of calcination temperature on the structure and properties of the catalyst and the preferential oxidation of CO in a hydrogen-rich atmosphere containing CO2 were investigated. The results indicated that Cu/Mn-O-Ce solid solution was formed in all MnCu/Ce catalysts. Of theses sample, the one calcined at 600 ℃ had strong interaction among Mn, Cu and Ce, formed more ternary oxide solid solution with more oxygen vacancies/Ce3+, and revealed good CO-Prox activity. In addition, it was found that the addition of different percentage of Ar had little effects on the CO-Prox activity of the catalyst, while the space velocity and oxygen excess coefficient had great effects on the catalytic performance, and the presence of CO2 in the reaction feedstock gas had a negative effect on the CO-Prox reaction. At an oxygen excess coefficient of 1.2 and the space velocity of 20266−30400 mL/(g·h), the highest CO conversion rate reached 94.7%.
Structural features and combustion reactivity of residual carbon in fine slag from entrained-flow gasification
LÜ Deng-pan, BAI Yong-hui, WANG Jiao-fei, SONG Xu-dong, SU Wei-guang, YU Guang-suo, ZHU he, TANG Guang-jun
2021, 49(2): 129-136.   doi: 10.1016/S1872-5813(21)60011-7
[Abstract](548) [FullText HTML](131) [PDF 1332KB](66)
摘要:
气流床气化过程中产生的细渣含碳量很高,目前多以填埋的方式进行处理,将细渣用于循环流化床锅炉掺烧有望为细渣处理提供有利的技术。本研究选用宁东能源化工基地典型气化工艺GE、OMB及GSP产生的气化细渣为研究对象,利用物理吸附仪、激光拉曼及热重分析仪等仪器,系统研究了气化细渣中残炭的结构特征与燃烧特性。结果表明,原始气化细渣中的物质可分为黏结球形颗粒、多孔不规则颗粒与孤立的大球形颗粒,而酸洗后的气化细渣多以疏松细小的颗粒和多孔不规则块状颗粒存在;细渣中残炭的孔径尺寸主要分布在4−8 nm,且比表面积与残炭的活性位点大小顺序均为:GE > OMB > GSP;GE渣中残炭结构有序度最低,无定形炭结构最多,GSP则相反;GE渣中残炭燃烧速率最快,主要是由于GE渣中残炭有较大的比表面积、较多的无定形炭结构及较高的的活性位点,且GE渣中残炭的综合燃烧指数为5.26 × 10−7%2/(min2·℃3)。
Research progress of calcium-based adsorbents for CO2 capture and anti-sintering modification
GENG Yi-qi, GUO Yan-xia, FAN Biao, CHENG Fang-qin, CHENG Huai-gang
2021, 49(7): 998-1013.   doi: 10.1016/S1872-5813(21)60040-3
[Abstract](1078) [FullText HTML](204) [PDF 1222KB](153)
摘要:
利用CaO基吸附剂直接从高温烟气中捕集CO2因成本低、吸附性能好等优点成为CCUS(碳捕集、利用与封存)的重要技术之一。但CaO基吸附剂在碳酸化/煅烧吸脱附循环过程中存在易烧结的问题,导致其吸附性能急剧下降。本研究针对CaO基吸附剂全面总结了其吸附CO2的动力学、热力学及烧结机理,并重点综述了世界各国研究者在CaO基吸附剂抗烧结改性方面所做的研究,指出了各种方法的优点及其局限性。结果表明,水合作用改性可使吸附剂崩塌而获得更大的比表面积;酸溶液改性会在制备过程产生更多的气体和小分子物质提高吸附剂孔隙率;掺杂改性可以促进CaO对CO2的吸附和扩散,还可作为骨架分离CaO颗粒。经比较,掺杂改性工艺简单、性能好,是比较有前景的改性方法,以含钙固废制备抗烧结改性吸附剂是发展方向。
An analysis of waste gasification and its contribution to China’s transition towards carbon neutrality and zero waste cities
LEE Roh Pin, SEIDL Ludwig Georg, HUANG Qiu-liang, MEYER Bernd
2021, 49(8): 1057-1076.   doi: 10.1016/S1872-5813(21)60093-2
[Abstract](1059) [FullText HTML](267) [PDF 1125KB](120)
摘要:
Waste gasification has the potential to contribute to China’s transition towards carbon neutrality and zero waste cities via the recirculation of waste as secondary carbon feedstock for the production of chemicals with lower/and or zero carbon footprint, green hydrogen with zero carbon footprint and CO2-neutral synthetic liquid fuels. With China’s significant coal gasification capacity and associated experiences and expertise, Coal-to-X could act as a bridge to Waste-to-X for carbon intensive sectors such as the waste management, chemical production and mobility sectors. To illustrate the opportunities in these areas, this article presented highlights from dynamic global developments in waste gasification, focusing on pioneering industrial developments in Germany between 1980−2000’s as well as current international developments. Lessons learnt from previous and current waste gasification project deployment are shared and enabled the identification of problems which will have to be addressed in the transition from coal gasification towards mono-waste gasification technologies. Additionally, a qualitative evaluation of gasification technologies pointed to the strengths and weaknesses of fixed-bed, fluidized-bed and entrained-flow gasification principles in their application for waste gasification.
Research progress on NH3-SCR mechanism of metal-supported zeolite catalysts
ZHANG Wen-bo, CHEN Jia-ling, GUO Li, ZHENG Wei, WANG Guang-hua, ZHENG Shen-ke, WU Xiao-qin
2021, 49(9): 1294-1315.   doi: 10.1016/S1872-5813(21)60080-4
[Abstract](902) [FullText HTML](186) [PDF 1005KB](158)
摘要:
在NH3选择性催化还原(NH3-SCR)反应中,由于具有宽温度窗口和良好的水热稳定性,金属负载型分子筛是具有广泛应用潜力的脱硝催化剂。本文综述了Cu基和Fe基分子筛催化剂在NH3-SCR领域的研究进展,总结了催化剂的结构特征和NH3-SCR性能指标,并对相应的金属活性位点和反应机理进行了归纳。此外,系统介绍了密度泛函理论(DFT)计算在NH3-SCR反应机理中的应用及反应动力学的研究方法,并对比了不同催化剂体系下的表观动力学参数,为进一步研究金属负载型分子筛催化剂的NH3-SCR反应机理提供方法与思路。
Characteristics of MSWI fly ash with acid leaching treatment
CAO Yi-nan, LUO Jin-jing, SUN Shi-qiang
2021, 49(8): 1208-1218.   doi: 10.1016/S1872-5813(21)60119-6
[Abstract](255) [FullText HTML](73) [PDF 852KB](23)
摘要:
The chemical and mineralogical characteristics of fly ash from a municipal solid waste incineration (MSWI) in China and the influence of processing parameters on heavy metals removal during leaching were investigated in this work. The fly ash particles had complex surface structure with limited specific surface area. The alkali chloride and metal salts in MSWI fly ash showed evidently impact on leaching efficiency. Metal leachability was related to their properties and speciation in fly ash. Water-soluble salts such as KCl, NaCl and CaCl2 in fly ash were easily washed out. In this study, removal efficiency by water washing was achieved to 93.1% for Cl, 41.4% for Na, 48.5% for K and 24.8% for Ca, respectively. Mineralogical analysis also revealed change of fly ash mineral phases and specification distribution after water washing. Under liquid to solid ratio of 40∶1 L/kg and treatment time of 120 min, the leaching process achieved high dropping yields of toxicity characteristic leaching procedure (TCLP) concentrations for Cu, Zn Cd and Pb (80%−100%), moderate dropping yields for As (30%−80%) and relatively low dropping yields of Ni (< 30%). In addition, heavy metals such as Pb and Zn in fly ash with twice water washing treatment at a low liquid-solid ratio could reach lower TCLP concentrations. The result indicated that the combination process of twice water washing and one acid washing could significantly reduce the environmental risk of MSWI fly ash.
Lead poisoning and regeneration of Mn-Ce/TiO2 catalysts for NH3-SCR of NOx at low temperature
YAN Dong-jie, GUO Tong, YU Ya, CHEN Zhao-hui
2021, 49(1): 113-120.   doi: 10.1016/S1872-5813(21)60003-8
[Abstract](258) [FullText HTML](111) [PDF 1677KB](25)
摘要:
考察了Pb对Mn-Ce/TiO2低温选择性催化还原(SCR)脱硝活性的影响,并对Pb中毒的催化剂进行了再生;结合氮吸附、SEM、XRD、FT-IR、H2-TPR和NH3-TPD等表征结果,研究了Mn-Ce/TiO2催化剂Pb中毒和再生活性恢复的原因。结果表明,Pb对Mn-Ce/TiO2催化剂脱硝活性有明显的抑制作用;当Pb的含量为11%时,Mn-Ce/TiO2催化剂在180 ℃下的脱硝效率从原来100%下降至44%。Pb在Mn-Ce/TiO2中的掺杂使得催化剂的比表面积以及活性组分Mn4+和Ce3+的含量降低,影响了氧化还原循环反应(Mn4+ + Ce3+ ↔ Mn3+ + Ce4+)的进行;此外,Pb的加入破坏了催化剂的酸性位点,阻碍了催化剂对NH3的吸附和活化。经硝酸再生后的Mn-Ce/TiO2催化剂的脱硝活性几乎完全恢复,在80–150 ℃下其脱硝活性甚至超过新鲜未中毒的催化剂,其原因主要在于硝酸再生能恢复催化剂的氧化还原能力、增大比表面积、并形成新的酸位点。
Modification of the V2O5-WO3/TiO2 catalyst with Nb to reduce its activity for SO2 oxidation during the selective catalytic reduction of NOx
WANG Bo, BIAN Yao, FENG Shuo, WANG Shao-qi, SHEN Bo-xiong
2022, 50(4): 503-512.   doi: 10.1016/S1872-5813(21)60177-9
[Abstract](427) [FullText HTML](118) [PDF 1518KB](27)
摘要:
本文采用浸渍法制备了Nb改性的V2O5-WO3/TiO2催化剂,研究了脱硝反应中Nb负载量对催化剂SO2氧化活性的影响。结果表明,在350 °C下,Nb2O5负载量为2%的Nb2O5-V2O5-WO3/TiO2催化剂上的SO2氧化率最低(0.6%),而同时NOx 的转化率仍能达到95%。采用TGA、氮吸附、XRD、H2-TPR、CO2-TPD、XPS和in- situ DRIFTS等对催化剂进行了表征分析,结果显示,Nb改性后V2O5-WO3/TiO2催化剂的晶体结构没有发生明显改变,但是其比表面积小幅度下降,有助于减少对SO2的吸附;同时,改性后催化剂表面的吸附氧含量下降,氧化还原性能也稍微减弱,这有利于降低其对SO2的氧化活性。in-situ DRIFTS结果表明,Nb改性后的Nb-V2O5-WO3/TiO2催化剂反应过程中表面中间产物VOSO4的含量明显下降,从而减少了SO3的生成量。
Effect of preparation methods on the structure and catalytic performance of CeO2 for toluene combustion
QUAN Yan-hong, MIAO Chao, LI Tao, WANG Na, WU Meng-meng, ZHANG Ning, ZHAO Jin-xian, REN Jun
2021, 49(2): 211-219.   doi: 10.1016/S1872-5813(21)60014-2
[Abstract](438) [FullText HTML](78) [PDF 1338KB](46)
摘要:
采用溶胶-凝胶-超临界干燥法、水热法及共沉淀法分别合成了氧化铈气凝胶(CeO2-A)、纳米棒(CeO2-R)和纳米片(CeO2-F)。考察了不同形貌氧化铈的催化燃烧甲苯性能,通过多种方法分析表征了氧化铈样品的微观结构,讨论了不同方法制得的CeO2形貌结构对催化性能的影响。结果表明,CeO2-R和CeO2-F比表面积较低,并且仅暴露(111)晶面,催化燃烧甲苯活性较低。CeO2-A具有高比表面积和丰富的孔道结构,有利于反应物分子的吸附,而且同时暴露(100)和(111)两种活性晶面,增加了氧空位浓度(Osur/Olatt = 0.25)。此外,CeO2-A由于表面晶格氧移动性较强,有利于Ce3+/Ce4+氧化还原的循环,加快甲苯深度氧化反应的进行。因此,CeO2-A具有更加优异的催化燃烧甲苯活性,t50t90分别为223 和239 ℃,这主要归因于其大比表面积、高暴露活性晶面以及强晶格氧迁移性。
Advance on the pyrolytic transformation of cellulose
LI Cheng-yu, ZHANG Jun, YUAN Hao-ran, WANG Shu-rong, CHEN Yong
2021, 49(12): 1733-1751.   doi: 10.1016/S1872-5813(21)60134-2
[Abstract](3091) [FullText HTML](312) [PDF 1107KB](333)
摘要:
纤维素的热解技术是一种非常有应用前景的高值转化技术。本综述系统地介绍了纤维素的基础特性,深入讨论了纤维素热解机制、研究方法、催化剂类型及其他影响纤维素热解产物分布的因素。其中,不同类型催化剂的添加和反应装置结构的设计优化可以显著提高纤维素热解转化效率,改善产物种类分布和提高特定高值化学品的选择性,从而有效地提高纤维素热解产物的资源、能源化利用价值。最后,对纤维素热解未来技术研究的发展方向进行了展望。
Research progresses in the hydrogenation of carbon dioxide to certain hydrocarbon products
WANG Han, FAN Sheng, WANG Sen, DONG Mei, QIN Zhang-feng, FAN Wei-bin, WANG Jian-guo
2021, 49(11): 1609-1619.   doi: 10.1016/S1872-5813(21)60122-6
[Abstract](3074) [FullText HTML](215) [PDF 905KB](195)
摘要:
化石资源的大量使用导致CO2的大量排放,带来了严重的环境问题。与此同时,CO2又是一种清洁、无毒的含碳资源。将CO2作为原料,直接转化制备重要化学品,不仅可以减缓温室效应,同时也是一条有效利用含碳资源制备清洁燃料和化学品的新路线。本文概述了近年来关于CO2加氢制备一些烃类化合物(主要包括甲烷、烯烃和芳烃)的相关研究进展;重点分析了CO2加氢制烃类化合物相关过程催化剂的研发状态和对催化反应机理的认识,并对CO2加氢转化利用的未来发展进行了展望。
Preparation of core-shell catalysts for one-step synthesis of dimethyl ether from syngas
WANG Wen-li, WANG Yan, CHEN Yue-xian, ZHAO Wen-chao, LI Rui-feng
2013, 41(08): 1003-1009.  
[Abstract](2399) [PDF 13334KB](54)
Abstract:
A core-shell catalyst CuO-ZnO-Al2O3@Al2O3 for one-step synthesis of dimethyl ether from synthesis gas was prepared using glucose, sucrose or starch as template, and characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The thickness of the Al2O3 shell in the catalyst was altered by controlling the synthesis condition, such as temperature and time. The catalytic performance of dimethyl ether (DME) synthesized from CO hydrogenation on the catalysts were investigated. The conversion of CO and the selectivity of DME on CuO-ZnO-Al2O3@Al2O3 achieved 35.2% and 61.1% at 260 ℃, 5.0 MPa and 1 500 mL/(h·gcat), respectively.
Effect of wastewater treatment processes on thermal treatment properties of sewage sludge
JIE Li-Beng, Zheng-Shi-Mei, LI Chao
2009, 37(04): 501-505.  
[Abstract](1720) [PDF 1335KB](56)
Abstract:
The properties of pyrolysis and combustion for five different sewage sludges are studied by thermal gravimetric analysis at a heating rate of 10℃/min in the atomosphere of nitrogen and oxygen, respectively. The results show that both of the “anaerobic” wastewater treatment and the sludge anaerobic digestion make the organic compounds in sludge so complicated that the organic compounds decomposition and release temperature becomes higher during pyrolyzing, and the “aerobic + anaerobic” process makes the organic compounds in sludge more complicated than the “anaerobic +aerobic” process. There is no influence on the combustion process and the burnout point, but can make the combustion temperature of sludge higher. The thermal reaction mechanisms have been studied with šatava-šesták equation. It shows that the pyrolysis mechanism of these sludges is a process of volatile diffusion at first and then the chemical reaction function, while the combustion mechanism of them is a process of chemical reaction and diffusion function.