Supervisor：Chinese Academy of Sciences
Sponsors by：
Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
Editor-in-Chief：Fang yi tian
Email：rlhx@sxicc.ac.cn
ISSN 2097-213X
eISSN 1872-5813
CN 14-1410/TQ
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).
Synthesis of polyethylnaphthalenes base oil catalyzed by ionic liquid and its lubricating properties
, Available online ,
doi: 10.19906/j.cnki.JFCT.2022087
Abstract:
2023, 51(2): 129-144.
doi: 10.19906/j.cnki.JFCT.2022076
Abstract:
"Thermal Dissolution based Carbon Enrichment" (TDCE) is the thermal extraction of lignocellulosic biomass wastes using non/weak polar organic solvents under mild conditions (350 °C, nitrogen atmosphere). After a series of deoxygenation and aromatization reactions, the obtained target solid products Soluble and Deposit have the advantages of anhydrous, ashless, high calorific value, etc. At the same time, this technology also has the advantages that the solvent does not participate in the chemical reaction and can be recycled and reused. Therefore, thermal solution carbon enrichment is one of the effective ways to realize biomass energy conversion. This paper firstly introduces various ways of biomass utilization at present; and then focuses on the factors affecting carbon-enrichment, reaction mechanism and product utilization pathways of biomass thermal solution. Under the background of the national strategy of "carbon neutrality", biomass thermal solution carbon-enriching technology has obvious economic value and social significance.
"Thermal Dissolution based Carbon Enrichment" (TDCE) is the thermal extraction of lignocellulosic biomass wastes using non/weak polar organic solvents under mild conditions (350 °C, nitrogen atmosphere). After a series of deoxygenation and aromatization reactions, the obtained target solid products Soluble and Deposit have the advantages of anhydrous, ashless, high calorific value, etc. At the same time, this technology also has the advantages that the solvent does not participate in the chemical reaction and can be recycled and reused. Therefore, thermal solution carbon enrichment is one of the effective ways to realize biomass energy conversion. This paper firstly introduces various ways of biomass utilization at present; and then focuses on the factors affecting carbon-enrichment, reaction mechanism and product utilization pathways of biomass thermal solution. Under the background of the national strategy of "carbon neutrality", biomass thermal solution carbon-enriching technology has obvious economic value and social significance.
2023, 51(2): 145-154.
doi: 10.1016/S1872-5813(22)60033-1
Abstract:
Combining with the characteristics of high yield of mineral humic acid (HA) and high activity of biochemical HA, co-thermal oxidation of low rank coal and biomass to produce complex HA (MIXHA) was newly proposed. The mixture (MIX) of Heilongjiang lignite (HL) and wheat straw (WS) was co-thermally oxidized in 10% HNO3 solution to prepare MIXHA. This work focused on comparison of the macro morphology and microstructure of MIXHA between HLHA and WSHA by SEM, FT-IR and 13C NMR analyses, and explored the synergistic effect between HL and WS during the co-thermal oxidation process. The results show that MIXHA content is higher than the theoretical value. Decomposition of HNO3 molecular produces active oxygen atoms and nitrogen oxides to attack the molecular structure of WS and HL. Due to hydrogen bond rearrangement, glycosidic bond rupture, and crosslinking, plenty of alkyl radicals generated in WS are combined with the condensation aromatic ring in HL. Thus, the protonated aromatic carbon is changed into aliphatic substituted aromatic carbon. The obtained MIXHA is rich in oxygen-containing functional groups, and has high activity. Obvious characteristic peaks are observed in FTIR spectra of MIXHA. This work would provide a new idea for classification and resource utilization of low-rank coal and agricultural and forestry wastes.
Combining with the characteristics of high yield of mineral humic acid (HA) and high activity of biochemical HA, co-thermal oxidation of low rank coal and biomass to produce complex HA (MIXHA) was newly proposed. The mixture (MIX) of Heilongjiang lignite (HL) and wheat straw (WS) was co-thermally oxidized in 10% HNO3 solution to prepare MIXHA. This work focused on comparison of the macro morphology and microstructure of MIXHA between HLHA and WSHA by SEM, FT-IR and 13C NMR analyses, and explored the synergistic effect between HL and WS during the co-thermal oxidation process. The results show that MIXHA content is higher than the theoretical value. Decomposition of HNO3 molecular produces active oxygen atoms and nitrogen oxides to attack the molecular structure of WS and HL. Due to hydrogen bond rearrangement, glycosidic bond rupture, and crosslinking, plenty of alkyl radicals generated in WS are combined with the condensation aromatic ring in HL. Thus, the protonated aromatic carbon is changed into aliphatic substituted aromatic carbon. The obtained MIXHA is rich in oxygen-containing functional groups, and has high activity. Obvious characteristic peaks are observed in FTIR spectra of MIXHA. This work would provide a new idea for classification and resource utilization of low-rank coal and agricultural and forestry wastes.
2023, 51(2): 155-164.
doi: 10.1016/S1872-5813(22)60018-5
Abstract:
In this study, a series of catalysts with different Fe3O4 to iron carbide ratios were obtained by carburizing the α-Fe2O3 precursor prepared by co-precipitation method, under various carburization conditions. XRD, Mössbauer spectroscopy, XPS, and Raman spectroscopy were used to characterize the bulk and surface phase compositions of the Fe-based catalysts. The results show that increasing the carburization temperature and prolonging the carburization time lead to higher iron carbide concentration. To explore the active phase of CO2 formation, the catalysts were tested under different reaction conditions by tuning either CO conversion or H2O partial pressure. It turns out that the catalytic performance of the Fe-based catalyst in the FTS and water-gas shift (WGS) reactions is influenced by both the content of iron carbide and the degree of carbon deposition. Under typical Fischer-Tropsch reaction condition, the CO2 selectivity is determined by the CO conversion rather than the Fe3O4 content in the catalyst, meaning that the WGS reaction is here limited by the kinetic factors. On the contrary, adding H2O to the reaction gas results in the trend that higher CO2 selectivity is promoted by higher content of Fe3O4 in the Fe-based catalyst. It seems that Fe3O4 is the main active phase for the WGS reaction in the iron-based catalyst for FTS. These results provide a new insight into the active phase of CO2 generation on the Fe-based catalysts, which could be the theoretical basis for the design of new industrial FTS catalysts with low CO2 selectivity.
In this study, a series of catalysts with different Fe3O4 to iron carbide ratios were obtained by carburizing the α-Fe2O3 precursor prepared by co-precipitation method, under various carburization conditions. XRD, Mössbauer spectroscopy, XPS, and Raman spectroscopy were used to characterize the bulk and surface phase compositions of the Fe-based catalysts. The results show that increasing the carburization temperature and prolonging the carburization time lead to higher iron carbide concentration. To explore the active phase of CO2 formation, the catalysts were tested under different reaction conditions by tuning either CO conversion or H2O partial pressure. It turns out that the catalytic performance of the Fe-based catalyst in the FTS and water-gas shift (WGS) reactions is influenced by both the content of iron carbide and the degree of carbon deposition. Under typical Fischer-Tropsch reaction condition, the CO2 selectivity is determined by the CO conversion rather than the Fe3O4 content in the catalyst, meaning that the WGS reaction is here limited by the kinetic factors. On the contrary, adding H2O to the reaction gas results in the trend that higher CO2 selectivity is promoted by higher content of Fe3O4 in the Fe-based catalyst. It seems that Fe3O4 is the main active phase for the WGS reaction in the iron-based catalyst for FTS. These results provide a new insight into the active phase of CO2 generation on the Fe-based catalysts, which could be the theoretical basis for the design of new industrial FTS catalysts with low CO2 selectivity.
Preparation of mesoporous NiMo catalyst by mechanical ball milling for hydrogenation of phenanthrene
2023, 51(2): 165-174.
doi: 10.19906/j.cnki.JFCT.2022045
Abstract:
The NiMo catalysts were prepared using the mechanical ball milling method, and their structures were characterized by XRD and XPS to investigate the effects of the Ni/(Ni+Mo) ratio on catalyst composition and structure, as well as the performance of phenanthrene hydrogenation. The results show that the catalysts prepared by this method have good dispersion of active components Ni and Mo, and are mesoporous catalysts with a concentrated pore size distribution in the range of 2−10 nm. The specific surface area and MoIV content of the catalysts increase first and then decrease as the Ni/(Ni+Mo) ratio increases, both reaching maximum values at 0.33. The moderate amount of Ni promotes Mo sulfidation to form the NiMoS active phase, while the excessive amount of Ni forms NixSy, which covers active sites and reduces the hydrogenation activity. When the Ni/(Ni+Mo) ratio maintains at 0.33, the specific surface area of the catalyst decreases as Ni and Mo content increases, while MoIV content shows an increase trend. Raising the amount of sulfurizing agent ammonium thiosulfate (ATS) could increase both the specific surface area and MoIV content of the catalyst. It is observed that the effect of the Ni/(Ni+Mo) ratio on phenanthrene conversion is consistent with the MoIV content of catalyst, and the maximum value of 74.7% is obtained at the Ni/(Ni+Mo) ratio of 0.33. This further rises to 96.5% when the Ni and Mo contents and S/Mo ratio increase to 4.8%, 16% and 4.5, respectively. Meanwhile, the total selectivity and yield of octahydrophenanthrene and perhydrophenanthrene reach 83.9% and 80.9%, respectively. Furthermore, perhydrophenanthrene is mainly formed by hydrogenation of side ring of phenanthrene.
The NiMo catalysts were prepared using the mechanical ball milling method, and their structures were characterized by XRD and XPS to investigate the effects of the Ni/(Ni+Mo) ratio on catalyst composition and structure, as well as the performance of phenanthrene hydrogenation. The results show that the catalysts prepared by this method have good dispersion of active components Ni and Mo, and are mesoporous catalysts with a concentrated pore size distribution in the range of 2−10 nm. The specific surface area and MoIV content of the catalysts increase first and then decrease as the Ni/(Ni+Mo) ratio increases, both reaching maximum values at 0.33. The moderate amount of Ni promotes Mo sulfidation to form the NiMoS active phase, while the excessive amount of Ni forms NixSy, which covers active sites and reduces the hydrogenation activity. When the Ni/(Ni+Mo) ratio maintains at 0.33, the specific surface area of the catalyst decreases as Ni and Mo content increases, while MoIV content shows an increase trend. Raising the amount of sulfurizing agent ammonium thiosulfate (ATS) could increase both the specific surface area and MoIV content of the catalyst. It is observed that the effect of the Ni/(Ni+Mo) ratio on phenanthrene conversion is consistent with the MoIV content of catalyst, and the maximum value of 74.7% is obtained at the Ni/(Ni+Mo) ratio of 0.33. This further rises to 96.5% when the Ni and Mo contents and S/Mo ratio increase to 4.8%, 16% and 4.5, respectively. Meanwhile, the total selectivity and yield of octahydrophenanthrene and perhydrophenanthrene reach 83.9% and 80.9%, respectively. Furthermore, perhydrophenanthrene is mainly formed by hydrogenation of side ring of phenanthrene.
2023, 51(2): 175-185.
doi: 10.1016/S1872-5813(22)60034-3
Abstract:
ZSM-23 zeolite was successfully synthesized in a dual-template system, and ZSM-23-Al2O3 composites with different ratios were also prepared. The hydroisomerization performance of Pt/ZSM-23 catalyst was manipulated by introducing Al2O3, and the influence of Al2O3 on physicochemical properties was investigated by XRD, SEM, TEM, N2 physical adsorption-desorption and NH3-TPD characterizations. The results showed that Al2O3 improved the dispersion of Pt, significantly reduced the acid sites concentration of the catalyst, and regulated the metal-acid balance in quantitative. The suitable metal-acid balance concentration could improve the selectivity of isomers and suppress the cracking reactions. Meanwhile, Al2O3 dispersed the ZSM-23 grains, which improved the dispersion and increased the number of exposed pores in ZSM-23. Thus the diffusion efficiency of reactants and intermediates could be promoted and the isomer products selectivity could be improved. All composite catalysts showed high selectivity of isomer products, among which, Pt/(9Z-1Al) had the highest yield of isomer products due to its suitable metal-acid concentration balance, reached 60% at 340 ℃, which was a significant improvement compared with Pt/ZSM-23 (42%). When the reaction temperature was lower than 310 ℃, the pore mouth mechanism dominated in Pt/ZSM-23, while the key-lock mechanism was significantly strengthened at higher reaction temperature. After the introduction of Al2O3, more adjacent pores in ZSM-23 were exposed and the key-lock mechanism became the domination, which led to a large number of 7/8Me-C15 isomers.
ZSM-23 zeolite was successfully synthesized in a dual-template system, and ZSM-23-Al2O3 composites with different ratios were also prepared. The hydroisomerization performance of Pt/ZSM-23 catalyst was manipulated by introducing Al2O3, and the influence of Al2O3 on physicochemical properties was investigated by XRD, SEM, TEM, N2 physical adsorption-desorption and NH3-TPD characterizations. The results showed that Al2O3 improved the dispersion of Pt, significantly reduced the acid sites concentration of the catalyst, and regulated the metal-acid balance in quantitative. The suitable metal-acid balance concentration could improve the selectivity of isomers and suppress the cracking reactions. Meanwhile, Al2O3 dispersed the ZSM-23 grains, which improved the dispersion and increased the number of exposed pores in ZSM-23. Thus the diffusion efficiency of reactants and intermediates could be promoted and the isomer products selectivity could be improved. All composite catalysts showed high selectivity of isomer products, among which, Pt/(9Z-1Al) had the highest yield of isomer products due to its suitable metal-acid concentration balance, reached 60% at 340 ℃, which was a significant improvement compared with Pt/ZSM-23 (42%). When the reaction temperature was lower than 310 ℃, the pore mouth mechanism dominated in Pt/ZSM-23, while the key-lock mechanism was significantly strengthened at higher reaction temperature. After the introduction of Al2O3, more adjacent pores in ZSM-23 were exposed and the key-lock mechanism became the domination, which led to a large number of 7/8Me-C15 isomers.
2023, 51(2): 186-196.
doi: 10.1016/S1872-5813(22)60042-2
Abstract:
A highly efficient cerium-modified Cu/hexagonal mesoporous silica (xCe-Cu/HMS) catalyst for the vapor-phase hydrogenation of dimethyl oxalate (DMO) into ethylene glycol (EG) was prepared using an ammonia evaporation method. The Ce promoter can significantly improve the performance of the catalyst, and the best catalytic performance was obtained after the introduction of 1.2% Ce promoter on Cu/HMS. The DMO conversion and EG selectivity got to 99.6% and 96.3%, respectively, under moderate conditions (200 °C, 2.0 MPa, H2/DMO = 100 and LHSVDMO = 1.2 h−1). Characterization results revealed that Ce modification can enhance the interaction between Cu and the support, improve the dispersion of Cu on HMS, and maintain the appropriate ratio of Cu+/(Cu++Cu0). In this study, a simple and low-cost method was used to synthesize Ce-modified Cu-HMS catalysts, which showed excellent catalytic performance in conversion of DMO to EG under moderate conditions.
A highly efficient cerium-modified Cu/hexagonal mesoporous silica (xCe-Cu/HMS) catalyst for the vapor-phase hydrogenation of dimethyl oxalate (DMO) into ethylene glycol (EG) was prepared using an ammonia evaporation method. The Ce promoter can significantly improve the performance of the catalyst, and the best catalytic performance was obtained after the introduction of 1.2% Ce promoter on Cu/HMS. The DMO conversion and EG selectivity got to 99.6% and 96.3%, respectively, under moderate conditions (200 °C, 2.0 MPa, H2/DMO = 100 and LHSVDMO = 1.2 h−1). Characterization results revealed that Ce modification can enhance the interaction between Cu and the support, improve the dispersion of Cu on HMS, and maintain the appropriate ratio of Cu+/(Cu++Cu0). In this study, a simple and low-cost method was used to synthesize Ce-modified Cu-HMS catalysts, which showed excellent catalytic performance in conversion of DMO to EG under moderate conditions.
2023, 51(2): 197-204.
doi: 10.1016/S1872-5813(22)60052-5
Abstract:
Hydrogen production from electrolyzed water driven by sustainable energy is an effective way to achieve the hydrogen economy with zero carbon emission. Alkaline electrocatalytic hydrogen evolution reaction (HER) is one of the main energy transforming processes in the field of electrolytic water technology. The development of active and cost-effective nonprecious catalytic electrodes is of great importance to alkaline hydrogen evolution reaction. Amorphous nanosized nickel-boron alloy particles (NiB-COS) have been obtained by using chitosan oligosaccharides (COS) as a stabilizer via chemical reduction method. The as-prepared electrocatalysts have been used for the hydrogen evolution reaction (HER). The electrocatalysts have been characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma analysis (ICP) and X-ray photoelectron spectroscopy (XPS). NiB-COS displays a significant increase in hydrogen evolution reaction properties in alkaline media, affording low overpotentials of 49.4 mV at 10 mA/cm2 and 15.1 mV onset overpotential for the hydrogen evolution reaction. Tafel slope of NiB-COS is 86.1 mV/dec. Remarkably, the formation of a nickel-boron alloyed phase and the decrease of particle size are helpful to improve HER activity of NiB-COS. The experimental data indicated that the NiB-COS showed excellent long-term stability as a very active electrocatalyst.
Hydrogen production from electrolyzed water driven by sustainable energy is an effective way to achieve the hydrogen economy with zero carbon emission. Alkaline electrocatalytic hydrogen evolution reaction (HER) is one of the main energy transforming processes in the field of electrolytic water technology. The development of active and cost-effective nonprecious catalytic electrodes is of great importance to alkaline hydrogen evolution reaction. Amorphous nanosized nickel-boron alloy particles (NiB-COS) have been obtained by using chitosan oligosaccharides (COS) as a stabilizer via chemical reduction method. The as-prepared electrocatalysts have been used for the hydrogen evolution reaction (HER). The electrocatalysts have been characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma analysis (ICP) and X-ray photoelectron spectroscopy (XPS). NiB-COS displays a significant increase in hydrogen evolution reaction properties in alkaline media, affording low overpotentials of 49.4 mV at 10 mA/cm2 and 15.1 mV onset overpotential for the hydrogen evolution reaction. Tafel slope of NiB-COS is 86.1 mV/dec. Remarkably, the formation of a nickel-boron alloyed phase and the decrease of particle size are helpful to improve HER activity of NiB-COS. The experimental data indicated that the NiB-COS showed excellent long-term stability as a very active electrocatalyst.
2023, 51(2): 205-214.
doi: 10.1016/S1872-5813(22)60036-7
Abstract:
In this work we report the feasible modification of graphitic carbon nitride (g-C3N4) polymer through a post-functionalization progress. The resultant photocatalyst exhibits boron doping and mesoporous structure with a high surface area of 125 m2/g, leading in an increased surface activity for photocatalytic water splitting reaction. X-ray diffraction, X-ray photoelectron spectroscopy, PL emission spectra and UV-Vis spectra were used to detect the properties of as-prepared samples. Based on X-ray photoelectron spectroscopy analysis, boron is proposed to dope in the g-C3N4 lattice. Optical studies indicated that boron doped g-C3N4 exhibits enhanced and extended light absorbance in the visible-light region and a much lower intensity of PL emission spectra compared to pure g-C3N4. As a result, boron doped g-C3N4 shows activity of 10.2 times higher than the pristine g-C3N4 for photocatalytic hydrogen evolution. This work may provide a way to design efficient and mesoporous photocatalysts through post modification.
In this work we report the feasible modification of graphitic carbon nitride (g-C3N4) polymer through a post-functionalization progress. The resultant photocatalyst exhibits boron doping and mesoporous structure with a high surface area of 125 m2/g, leading in an increased surface activity for photocatalytic water splitting reaction. X-ray diffraction, X-ray photoelectron spectroscopy, PL emission spectra and UV-Vis spectra were used to detect the properties of as-prepared samples. Based on X-ray photoelectron spectroscopy analysis, boron is proposed to dope in the g-C3N4 lattice. Optical studies indicated that boron doped g-C3N4 exhibits enhanced and extended light absorbance in the visible-light region and a much lower intensity of PL emission spectra compared to pure g-C3N4. As a result, boron doped g-C3N4 shows activity of 10.2 times higher than the pristine g-C3N4 for photocatalytic hydrogen evolution. This work may provide a way to design efficient and mesoporous photocatalysts through post modification.
2023, 51(2): 215-224.
doi: 10.19906/j.cnki.JFCT.2022042
Abstract:
In this experiment, a Z-scheme nitrogen-deficient graphite-phase carbon nitride (LaFeO3/CQDs-g-C3Nx) composite photocatalyst was prepared. The catalyst was characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflection (UV-Vis DRS), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the introduction of nitrogen defects and CQDs enhanced the migration efficiency of photogenerated carriers. The photocatalytic degradation rate of LaFeO3/CQDs-g-C3Nx composites for rhodamine B (RhB) was 3.98 times higher than that of pure g-C3N4, and had good photocatalytic stability. It also showed good degradation of antibiotics and other organic pollutants.
In this experiment, a Z-scheme nitrogen-deficient graphite-phase carbon nitride (LaFeO3/CQDs-g-C3Nx) composite photocatalyst was prepared. The catalyst was characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflection (UV-Vis DRS), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the introduction of nitrogen defects and CQDs enhanced the migration efficiency of photogenerated carriers. The photocatalytic degradation rate of LaFeO3/CQDs-g-C3Nx composites for rhodamine B (RhB) was 3.98 times higher than that of pure g-C3N4, and had good photocatalytic stability. It also showed good degradation of antibiotics and other organic pollutants.
2016, 44(7): 777-783.
摘要：
通过对28个最大镜质组反射率0.30%-2.05%镜煤样品的X射线衍射(XRD) 分析, 获得XRD结构参数, 得到这些参数随反射率增大呈现的阶段性规律。在镜质组反射率小于1.0%阶段, La和Lc急剧增加, d002迅速减小, 含氧官能团的脱落和脂肪长度支链化程度减小占主导; 在1.0%-1.6%阶段, La持续增加, d002先增加后减小, Lc先减小然后趋于平稳, 芳香体系脱氢和调整空间位阻同时进行; 在1.6%-2.0%阶段, d002持续减小, Lc和La的增大, 煤结构演化以芳构化为主。XRD结构参数演化与第一、二次煤化作用跃变关系密切。
通过对28个最大镜质组反射率0.30%-2.05%镜煤样品的X射线衍射(XRD) 分析, 获得XRD结构参数, 得到这些参数随反射率增大呈现的阶段性规律。在镜质组反射率小于1.0%阶段, La和Lc急剧增加, d002迅速减小, 含氧官能团的脱落和脂肪长度支链化程度减小占主导; 在1.0%-1.6%阶段, La持续增加, d002先增加后减小, Lc先减小然后趋于平稳, 芳香体系脱氢和调整空间位阻同时进行; 在1.6%-2.0%阶段, d002持续减小, Lc和La的增大, 煤结构演化以芳构化为主。XRD结构参数演化与第一、二次煤化作用跃变关系密切。
2016, 44(4): 385-393.
摘要：
以11种炼焦煤为研究对象,分别进行FT-IR和黏结指数G测试。采用PeakFit软件对FT-IR谱峰进行分峰拟合和定量计算,研究炼焦煤特征官能团含量与其黏结性间的关系。结果表明,煤黏结性大小与其FT-IR吸收峰密切相关,特别是3 000-2 800和3 700-3 000 cm-1两个吸收带;脂肪族结构是煤黏结性形成的主要决定因素,通常脂肪链越短或支链化程度越高,越有利于煤的黏结性形成;含-OH(或-NH)的氢键缔合结构可以与脂肪链协同作用,共同决定煤的黏结性能。不论煤分子有多大,只要是结构单元缩合度较小而作为桥键的脂肪链较多的结构形式,在热解过程中就会生成大量适度分子量、以结构单元为基元的液相物质。氢键是煤中主要的分子间作用形式,当若干形成氢键的官能团聚集缔合时,其相互作用会更强,甚至会形成类似超分子的结构;在形成胶质体阶段,这类氢键缔合的结构也会被打破,并形成以胶质体液相为主的物质。这些液相物质的存在,有利于胶质体的流动、黏连和固化成为半焦,从而最终获得优越的黏结性。
以11种炼焦煤为研究对象,分别进行FT-IR和黏结指数G测试。采用PeakFit软件对FT-IR谱峰进行分峰拟合和定量计算,研究炼焦煤特征官能团含量与其黏结性间的关系。结果表明,煤黏结性大小与其FT-IR吸收峰密切相关,特别是3 000-2 800和3 700-3 000 cm-1两个吸收带;脂肪族结构是煤黏结性形成的主要决定因素,通常脂肪链越短或支链化程度越高,越有利于煤的黏结性形成;含-OH(或-NH)的氢键缔合结构可以与脂肪链协同作用,共同决定煤的黏结性能。不论煤分子有多大,只要是结构单元缩合度较小而作为桥键的脂肪链较多的结构形式,在热解过程中就会生成大量适度分子量、以结构单元为基元的液相物质。氢键是煤中主要的分子间作用形式,当若干形成氢键的官能团聚集缔合时,其相互作用会更强,甚至会形成类似超分子的结构;在形成胶质体阶段,这类氢键缔合的结构也会被打破,并形成以胶质体液相为主的物质。这些液相物质的存在,有利于胶质体的流动、黏连和固化成为半焦,从而最终获得优越的黏结性。
2016, 44(3): 263-272.
摘要：
利用XRD和FT-IR考察了高温弱还原气氛下Na2O对两种硅铝含量不同的煤灰中矿物质组成的影响, 揭示了Na2O影响煤灰熔融特性的本质.通过FactSage计算了高温下矿物质反应的ΔG, 探讨了Na2O影响煤灰中矿物质组成的机理.结果表明, Na2O对煤灰矿物质组成的影响与原煤灰的硅铝含量密切相关.硅铝总含量82.89%的煤灰, Na2O含量为5%-20%时, 钠长石和霞石的生成是煤灰熔融温度降低的主要原因; 当Na2O含量大于20%时, 导致煤灰熔融温度降低的原因是霞石的生成.硅铝总含量47.85%的煤灰, Na2O含量小于10%时, 没有含钠矿物质生成; 当Na2O含量大于10%时, 主要生成菱硅钙钠石、青金石和含钠的硅铝酸盐矿物, 导致煤灰熔融温度降低.FactSage计算表明生成含Na矿物质反应的ΔG较小, 其在高温下更容易发生.
利用XRD和FT-IR考察了高温弱还原气氛下Na2O对两种硅铝含量不同的煤灰中矿物质组成的影响, 揭示了Na2O影响煤灰熔融特性的本质.通过FactSage计算了高温下矿物质反应的ΔG, 探讨了Na2O影响煤灰中矿物质组成的机理.结果表明, Na2O对煤灰矿物质组成的影响与原煤灰的硅铝含量密切相关.硅铝总含量82.89%的煤灰, Na2O含量为5%-20%时, 钠长石和霞石的生成是煤灰熔融温度降低的主要原因; 当Na2O含量大于20%时, 导致煤灰熔融温度降低的原因是霞石的生成.硅铝总含量47.85%的煤灰, Na2O含量小于10%时, 没有含钠矿物质生成; 当Na2O含量大于10%时, 主要生成菱硅钙钠石、青金石和含钠的硅铝酸盐矿物, 导致煤灰熔融温度降低.FactSage计算表明生成含Na矿物质反应的ΔG较小, 其在高温下更容易发生.
2016, 44(3): 279-286.
摘要：
利用高分辨率透射电子显微镜(HRTEM) 分析了三种不同变质程度煤样的结构特征.基于傅里叶-反傅里叶变换方法, 并结合Matlab、Arcgis和AutoCAD软件, 通过图像分析技术, 获得了HRTEM照片的晶格条纹参数.结果表明, 三种煤样的晶格条纹呈现不同特征, 按条纹长度分别归属于1×1-8×8共计八个类型.以3×3为临界点, 在1×1和2×2中, ML-8中芳香层片的比例高于DP-4和XM-3;在3×3-8×8中, ML-8中芳香层片的比例低于DP-4和XM-3.对比HRTEM和XRD参数d002发现, 随着镜质组反射率的增加d002都呈现递减趋势.
利用高分辨率透射电子显微镜(HRTEM) 分析了三种不同变质程度煤样的结构特征.基于傅里叶-反傅里叶变换方法, 并结合Matlab、Arcgis和AutoCAD软件, 通过图像分析技术, 获得了HRTEM照片的晶格条纹参数.结果表明, 三种煤样的晶格条纹呈现不同特征, 按条纹长度分别归属于1×1-8×8共计八个类型.以3×3为临界点, 在1×1和2×2中, ML-8中芳香层片的比例高于DP-4和XM-3;在3×3-8×8中, ML-8中芳香层片的比例低于DP-4和XM-3.对比HRTEM和XRD参数d002发现, 随着镜质组反射率的增加d002都呈现递减趋势.
2016, 44(7): 801-814.
摘要：
合成气直接催化转化制备低碳烯烃是C1化学与化工领域中一个极具挑战性的研究课题, 具有流程短、能耗低等优势, 已成为非石油路径生产烯烃的新途径。直接转化方式主要包括经由OX-ZEO双功能催化剂直接制低碳烯烃的双功能催化路线以及经由费托反应直接制备低碳烯烃的FTO路线。综述简述了近年来在合成气直接制备低碳烯烃方面的研究进展, 重点讨论了低碳烯烃的形成机理、新型催化剂的研发及助剂对其催化性能的影响, 并对合成气直接制烯烃的未来进行了展望。
合成气直接催化转化制备低碳烯烃是C1化学与化工领域中一个极具挑战性的研究课题, 具有流程短、能耗低等优势, 已成为非石油路径生产烯烃的新途径。直接转化方式主要包括经由OX-ZEO双功能催化剂直接制低碳烯烃的双功能催化路线以及经由费托反应直接制备低碳烯烃的FTO路线。综述简述了近年来在合成气直接制备低碳烯烃方面的研究进展, 重点讨论了低碳烯烃的形成机理、新型催化剂的研发及助剂对其催化性能的影响, 并对合成气直接制烯烃的未来进行了展望。
2018, 46(2): 179-188.
摘要：
采用原位合成法在γ-Al2O3表面合成了锌铝水滑石，再通过顺次浸渍法制备了一系列掺杂稀土改性的M（M=Y、La、Ce、Sm、Gd）/Cu/ZnAl催化材料，并将其应用于甲醇水蒸气重整制氢反应。探讨了稀土掺杂改性对Cu/ZnAl催化剂催化性能的影响，并采用XRD、SEM-EDS、BET、H2-TPR、XPS和N2O滴定等手段对催化剂进行了表征。结果表明，催化剂的活性与Cu比表面积和催化剂的还原性质密切相关，Cu比表面积越大，还原温度越低，催化活性越高。稀土Ce、Sm、Gd的引入能改善活性组分Cu的分散度、Cu比表面积以及催化剂的还原性质，进而提高催化剂的催化活性。其中，Ce/Cu/ZnAl催化剂表现出最佳的催化活性，在反应温度为250 ℃时，甲醇转化率达到100%，CO含量为0.39%，相比Cu/ZnAl催化剂，甲醇转化率提高了近40%。
采用原位合成法在γ-Al2O3表面合成了锌铝水滑石，再通过顺次浸渍法制备了一系列掺杂稀土改性的M（M=Y、La、Ce、Sm、Gd）/Cu/ZnAl催化材料，并将其应用于甲醇水蒸气重整制氢反应。探讨了稀土掺杂改性对Cu/ZnAl催化剂催化性能的影响，并采用XRD、SEM-EDS、BET、H2-TPR、XPS和N2O滴定等手段对催化剂进行了表征。结果表明，催化剂的活性与Cu比表面积和催化剂的还原性质密切相关，Cu比表面积越大，还原温度越低，催化活性越高。稀土Ce、Sm、Gd的引入能改善活性组分Cu的分散度、Cu比表面积以及催化剂的还原性质，进而提高催化剂的催化活性。其中，Ce/Cu/ZnAl催化剂表现出最佳的催化活性，在反应温度为250 ℃时，甲醇转化率达到100%，CO含量为0.39%，相比Cu/ZnAl催化剂，甲醇转化率提高了近40%。
2016, 44(9): 1034-1042.
摘要：
通过在一种真实煤灰中添加不同的氧化物或直接用氧化物配制合成灰，探究了不同灰成分对灰熔融特性的影响规律。利用FactSage 7.0对不同灰分的熔融过程进行了热力学模拟，通过熔融过程中的矿物质变化为各种灰成分对熔融特性的影响规律提供理论依据。结果表明，氧化钠对灰熔点的降低作用源于钠长石和霞石对钙长石的取代；氧化镁含量的增加对灰熔点起先降低后升高的作用，当氧化镁含量超过一定时，产生的镁橄榄石能够升高灰熔点；硫对灰熔点的升高作用源于镁橄榄石和硫酸钙对透辉石的取代；氧化钙含量的增加对灰熔点起到先降低后升高的作用，当氧化钙含量超过一定时，硅从熔点较低的矿物质迁移到熔点较高的矿物质中，升高了灰熔点。在与硅氧单元体结合的过程中，氧化钠优先于氧化钙；与氧化钙和硅氧单元体结合的氧化物的优先级为：氧化铝>氧化镁>氧化铁。
通过在一种真实煤灰中添加不同的氧化物或直接用氧化物配制合成灰，探究了不同灰成分对灰熔融特性的影响规律。利用FactSage 7.0对不同灰分的熔融过程进行了热力学模拟，通过熔融过程中的矿物质变化为各种灰成分对熔融特性的影响规律提供理论依据。结果表明，氧化钠对灰熔点的降低作用源于钠长石和霞石对钙长石的取代；氧化镁含量的增加对灰熔点起先降低后升高的作用，当氧化镁含量超过一定时，产生的镁橄榄石能够升高灰熔点；硫对灰熔点的升高作用源于镁橄榄石和硫酸钙对透辉石的取代；氧化钙含量的增加对灰熔点起到先降低后升高的作用，当氧化钙含量超过一定时，硅从熔点较低的矿物质迁移到熔点较高的矿物质中，升高了灰熔点。在与硅氧单元体结合的过程中，氧化钠优先于氧化钙；与氧化钙和硅氧单元体结合的氧化物的优先级为：氧化铝>氧化镁>氧化铁。
2016, 44(11): 1388-1393.
摘要：
分别以β、ZSM-5和USY分子筛为载体，采用浸渍法制备了锰铈催化剂，对其低温NH3-SCR反应性能进行了评价，并采用XRD、BET、NH3-TPD、H2-TPR以及XPS对催化剂进行了表征。结果表明，三种分子筛负载的锰铈催化剂均具有较好的低温NH3-SCR反应活性，其中，Mn-Ce/USY的催化性能最好，在107℃时NOx转化率可达到90%。负载锰铈后催化剂的比表面积和孔体积均有所下降；活性组分MnOx主要以无定型态分布于催化剂表面，且在ZSM-5上检测到聚集的CeO2。催化剂表面弱酸对低温NH3-SCR反应起主要作用，催化剂表面上活性组分的表面浓度和氧化态明显不同，较高的Mn4+/Mn3+原子比和吸附氧表面浓度对提高催化剂的低温NH3-SCR反应活性有利。
分别以β、ZSM-5和USY分子筛为载体，采用浸渍法制备了锰铈催化剂，对其低温NH3-SCR反应性能进行了评价，并采用XRD、BET、NH3-TPD、H2-TPR以及XPS对催化剂进行了表征。结果表明，三种分子筛负载的锰铈催化剂均具有较好的低温NH3-SCR反应活性，其中，Mn-Ce/USY的催化性能最好，在107℃时NOx转化率可达到90%。负载锰铈后催化剂的比表面积和孔体积均有所下降；活性组分MnOx主要以无定型态分布于催化剂表面，且在ZSM-5上检测到聚集的CeO2。催化剂表面弱酸对低温NH3-SCR反应起主要作用，催化剂表面上活性组分的表面浓度和氧化态明显不同，较高的Mn4+/Mn3+原子比和吸附氧表面浓度对提高催化剂的低温NH3-SCR反应活性有利。
2016, 44(6): 732-737.
摘要：
考察了碱处理、先碱后两步酸处理对HZSM-5分子筛物化性质以及苯与甲醇烷基化反应性能的影响。结果表明, 碱处理在脱除分子筛中非骨架硅的同时, 提高了晶孔的利用率, 也中和了分子筛的强酸中心, 使催化剂活化甲醇的能力减弱, 苯与甲醇反应活性降低; 先碱后两步酸处理既脱除了分子筛中的非骨架铝, 也恢复了一部分强酸中心, 提高了苯与甲醇的反应活性。进一步考察了先碱后两步酸处理中不同碱浓度的影响, 结果表明, 适宜浓度的碱处理后再两步酸处理, 一方面, 能脱除分子筛的非骨架硅铝物种, 使分子筛的颗粒粒径更加均匀; 另一方面, 分子筛的强酸中心有所减少, 降低了催化剂的积炭失活速率, 苯转化率提高15%以上。
考察了碱处理、先碱后两步酸处理对HZSM-5分子筛物化性质以及苯与甲醇烷基化反应性能的影响。结果表明, 碱处理在脱除分子筛中非骨架硅的同时, 提高了晶孔的利用率, 也中和了分子筛的强酸中心, 使催化剂活化甲醇的能力减弱, 苯与甲醇反应活性降低; 先碱后两步酸处理既脱除了分子筛中的非骨架铝, 也恢复了一部分强酸中心, 提高了苯与甲醇的反应活性。进一步考察了先碱后两步酸处理中不同碱浓度的影响, 结果表明, 适宜浓度的碱处理后再两步酸处理, 一方面, 能脱除分子筛的非骨架硅铝物种, 使分子筛的颗粒粒径更加均匀; 另一方面, 分子筛的强酸中心有所减少, 降低了催化剂的积炭失活速率, 苯转化率提高15%以上。
2018, 46(1): 92-98.
摘要：
通过建立具有更精确的SO3组分的实验室模拟烟气系统，同步研究了反应物浓度对硫酸氢铵和硫酸铵生成率和生成进度（生成速率）的影响。在实验浓度范围内，硫酸氢铵的开始生成温度为230-270℃，峰值温度为180-240℃，硫酸铵开始生成温度及峰值温度总体上比硫酸氢铵低40℃左右。硫酸氢铵的生成率明显高于硫酸铵，根据NH3和SO3浓度与物质的量比不同，烟温到120℃时，硫酸氢铵的生成率为64%-90%，硫酸铵的生成率为6%-15%，硫酸氢铵的生成率为硫酸铵的6-10倍。反应物浓度的增加会促进硫酸氢铵和硫酸铵的生成，且SO3较NH3更有利于硫酸氢铵的生成。硫酸氢铵和硫酸铵生成份额随温度的变化呈单峰状，且随着反应物浓度的增加，其峰值所在的温度区间逐渐升高。
通过建立具有更精确的SO3组分的实验室模拟烟气系统，同步研究了反应物浓度对硫酸氢铵和硫酸铵生成率和生成进度（生成速率）的影响。在实验浓度范围内，硫酸氢铵的开始生成温度为230-270℃，峰值温度为180-240℃，硫酸铵开始生成温度及峰值温度总体上比硫酸氢铵低40℃左右。硫酸氢铵的生成率明显高于硫酸铵，根据NH3和SO3浓度与物质的量比不同，烟温到120℃时，硫酸氢铵的生成率为64%-90%，硫酸铵的生成率为6%-15%，硫酸氢铵的生成率为硫酸铵的6-10倍。反应物浓度的增加会促进硫酸氢铵和硫酸铵的生成，且SO3较NH3更有利于硫酸氢铵的生成。硫酸氢铵和硫酸铵生成份额随温度的变化呈单峰状，且随着反应物浓度的增加，其峰值所在的温度区间逐渐升高。
2013, 41(08): 1003-1009.
Abstract:
2009, 37(04): 501-505.
Abstract:
