Regulating crystal phase of TiO2 to enhance catalytic activity of Ni/TiO2 for solar-driven dry reforming of methane
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摘要: Ni/TiO2催化剂被广泛应用于光热干重整反应中，然而不同TiO2晶相对于反应性能的影响尚不清楚。本文通过改变锐钛矿TiO2的焙烧温度，成功制备了不同金红石/锐钛矿混合比例的载体。结构表征表明，锐钛矿TiO2具有较强的金属-载体间相互作用，促使Ni/TiO2在还原过程中形成TiOx包覆层，大幅减少暴露的Ni活性位点。随着金红石/锐钛矿比例的增加，金属-载体间相互作用变弱，TiOx包覆层逐渐消失，从而促进了Ni活性位点的暴露。暴露的Ni位点不仅可增强可见光吸收，同时也提高了CH4的解离能力。性能评价显示，金红石/锐钛矿比例对光热干重整反应活性影响较大。具有金红石相的Ni/TiO2-950催化剂表现出最高的反应活性，H2和CO产率分别达到87.4和220.2 mmol/(g·h)，分别为锐钛矿相Ni/TiO2-700催化剂的257倍和130倍。本研究表明，通过改变TiO2晶体结构可有效提高光热干重整反应活性，从而为高效光热催化剂的设计提供了一条简单易行的策略。
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关键词:
- 干重整反应 /
- 光热催化 /
- 晶相 /
- TiO2 /
- 金属-载体间相互作用
Abstract: Ni/TiO2 catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO2 remains unclear. In this work, the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO2. Structural characterizations revealed that a distinct TiOx coating on the Ni nanoparticles (NPs) was evident for Ni/TiO2-700 catalyst due to strong metal-support interaction. It is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased, thereby enhancing the exposure of Ni active sites. The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4, which led to the much elevated catalytic activity for Ni/ TiO2-950 in which rutile dominated. Therefore, the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio. Ni/TiO2-950, characterized by a predominant rutile phase, exhibited the highest DRM reactivity, with remarkable H2 and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h), respectively. These rates were approximately 257 and 130 times higher, respectively, compared to those obtained on Ni/TiO2-700 with anatase. This study suggests that the optimization of crystal structure of TiO2 support can effectively enhance the performance of photothermal DRM reaction.-
Key words:
- Dry reforming of methane /
- photothermal catalysis /
- crystal phase /
- TiO2 /
- metal-support interaction
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Figure 1 (a) XRD patterns of TiO2-X supports; (b) Raman spectra of the TiO2-X supports; (c) XRD patterns of reduced Ni/TiO2-X catalysts; (d) UV-Vis DRS spectra of reduced Ni/TiO2-X catalysts.
Figure 2 SEM images of the TiO2-X catalysts (a) TiO2-700, (b) TiO2-850, (c) TiO2-900 and (d) TiO2-950.
Figure 3 (HR)TEM images and histogram for Ni particle size distribution of the reduced Ni/TiO2-X catalysts. (a–c) Ni/TiO2-700, (d–f) Ni/TiO2-850, (g–i) Ni/TiO2-900 and (j–l) Ni/TiO2-950.
Figure 4 (a) Production rate of CO and H2 on Ni/TiO2-X catalysts, reaction conditions: 10 mg catalyst, 7.9 W cm−2, 60 L/(g·h); (b) Production rate of CO and H2 on the Ni/TiO2-950 catalysts with different light intensity, reaction conditions: 10 mg catalyst, 60 L/(g·h); (c) Catalytic performance of the Ni/TiO2-950 catalysts with different catalyst mass, reaction conditions: 15.0 W cm−2; (d) Solar-to-fuel efficiency of the Ni/TiO2-950 catalyst with different WHSV, reaction conditions: 5 mg catalyst, 15.0 W cm−2.
Figure 5 (a) H2-TPR profiles of TiO2-X and Ni/TiO2-X (solid lines: Ni/TiO2-X; dashed lines: TiO2-X).; (b) The O 1s XPS spectra of various Ni/TiO2-X catalysts.
Figure 6 (a) MS signal of H2 in CH4-TPSR-MS for various Ni/TiO2-X catalysts; (b) The Ni 2p XPS spectra of various Ni/TiO2-X catalysts; (c) Transient response curves obtained from propene hydrogenation-pulse experiment of Ni/TiO2-700; (d) Transient response curves obtained from propene hydrogenation-pulse experiment of Ni/TiO2-950.
Table 1 Physiochemical properties of various catalysts.
Catalysts aPhase contents/% bNi/% cNi/nm dNi/nm anatase rutile Ni/TiO2-700 100 0 5.27 15.0 13.3 Ni/TiO2-850 82.6 17.4 5.14 12.7 13.7 Ni/TiO2-900 14.1 85.9 5.12 13.4 14.4 Ni/TiO2-950 0 100 5.14 13.9 13.9 aThe phase content of TiO2-X was estimated from XRD. bThe Ni loading measured by XRF. cThe Ni crystal sizes after reduction were calculated from XRD. dThe Ni crystal sizes after reduction were calculated from TEM. 
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Table 2 The ratios of surface Ni/Ti before and after reduction, estimated by XPS.
Catalysts Ni/Ti ratio of reduced catalyst Ni/TiO2-700 0.05 Ni/TiO2-850 0.29 Ni/TiO2-900 0.32 Ni/TiO2-950 0.37
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[1] ALHASSAN A M, HUSSAIN I, TAIALLA O A, et al. Advances in catalytic dry reforming of methane (DRM): Emerging trends, current challenges, and future perspectives[J]. J Cleaner Prod, 2023: 138638. [2] LI R, ZHENG Y, GONG K, et al. Recent Advances in the Conversion of Methane to Syngas and Chemicals via Photocatalysis[J]. ChemPhotoChem, e202300240. [3] PAKHARE D, SPIVEY J. A review of dry (CO2) reforming of methane over noble metal catalysts[J]. Chem Soc Rev,2014,43(22):7813−7837. doi: 10.1039/C3CS60395D [4] ZHONG L, YU F, AN Y, et al. Cobalt carbide nanoprisms for direct production of lower olefins from syngas[J]. Nature,2016,538(7623):84−87. doi: 10.1038/nature19786 [5] YAO T, AN Y, YU H, et al. Support effects on Ru-based catalysts for Fischer-Tropsch synthesis to olefins[J]. J Fuel Chem Technol,2023,51(10):1400−1410. doi: 10.1016/S1872-5813(23)60351-2 [6] GONG K, WEI Y, DAI Y, et al. Carbon-encapsulated metallic Co nanoparticles for Fischer-Tropsch to olefins with low CO2 selectivity[J]. Appl Catal B: Environ,2022,316:121700. doi: 10.1016/j.apcatb.2022.121700 [7] SONG Y, OZDEMIR E, RAMESH S, et al. Dry reforming of methane by stable Ni–Mo nanocatalysts on single-crystalline MgO[J]. Science,2020,367(6479):777−781. doi: 10.1126/science.aav2412 [8] MARGOSSIAN T, LARMIER K, KIM S M, et al. Molecularly tailored nickel precursor and support yield a stable methane dry reforming catalyst with superior metal utilization[J]. J Am Chem Soc,2017,139(20):6919−6927. doi: 10.1021/jacs.7b01625 [9] HE Z, HUANG M, LIN T, et al. Recent Advances in Dry Reforming of Methane via Photothermocatalysis[J]. Acta Phys-Chim Sin, 2023, 39(9). [10] CHEN H, NANAYAKKARA C E, GRASSIAN V H. Titanium dioxide photocatalysis in atmospheric chemistry[J]. Chem Rev,2012,112(11):5919−5948. doi: 10.1021/cr3002092 [11] GÜNNEMANN C, HAISCH C, FLEISCH M, et al. Insights into different photocatalytic oxidation activities of anatase, brookite, and rutile single-crystal facets[J]. ACS Catal,2018,9(2):1001−1012. [12] ROOSE B, PATHAK S, STEINER U. Doping of TiO2 for sensitized solar cells[J]. Chem Soc Rev,2015,44(22):8326−8349. doi: 10.1039/C5CS00352K [13] BOJINOVA A, KRALCHEVSKA R, POULIOS I, et al. Anatase/rutile TiO2 composites: Influence of the mixing ratio on the photocatalytic degradation of Malachite Green and Orange II in slurry[J]. Mater Chem Phys,2007,106(2-3):187−192. doi: 10.1016/j.matchemphys.2007.05.035 [14] RUAN X, CUI X, CUI Y, et al. Favorable energy band alignment of TiO2 anatase/rutile heterophase homojunctions yields photocatalytic hydrogen evolution with quantum efficiency exceeding 45.6%[J]. Adv Energy Mater,2022,12(16):2200298. doi: 10.1002/aenm.202200298 [15] SAHEL K, ELSELLAMI L, MIRALI I, et al. Hydrogen peroxide and photocatalysis[J]. Appl Catal B: Environ,2016,188:106−112. doi: 10.1016/j.apcatb.2015.12.044 [16] LI T, CHENG J, LI D, et al. Hollow spherical Ni/ZrO2 as a superior catalyst for syngas production from photothermal synergistic dry reforming of methane[J]. Catal Sci Technol, 2024. [17] LORBER K, ZAVAŠNIK J, SANCHO-PARRAMON J, et al. On the mechanism of visible-light accelerated methane dry reforming reaction over Ni/CeO2−x catalysts[J]. Appl Catal B: Environ,2022,301:120745. doi: 10.1016/j.apcatb.2021.120745 [18] RAO Z, CAO Y, HUANG Z, et al. Insights into the nonthermal effects of light in dry reforming of methane to enhance the H2/CO ratio near unity over Ni/Ga2O3[J]. ACS Catal,2021,11(8):4730−4738. doi: 10.1021/acscatal.0c04826 [19] RAO Z, WANG K, CAO Y, et al. Light-reinforced key intermediate for anticoking to boost highly durable methane dry reforming over single atom Ni active sites on CeO2[J]. J Am Chem Soc,2023,145(45):24625−24635. [20] TAVASOLI A, GOUDA A, ZÄHRINGER T, et al. Enhanced hybrid photocatalytic dry reforming using a phosphated Ni-CeO2 nanorod heterostructure[J]. Nat Commun,2023,14(1):1435. doi: 10.1038/s41467-023-36982-3 [21] XIE T, ZHANG Z Y, ZHENG H Y, et al. Enhanced photothermal catalytic performance of dry reforming of methane over Ni/mesoporous TiO2 composite catalyst[J]. Chem Eng J,2022,429:132507. doi: 10.1016/j.cej.2021.132507 [22] ZHANG Q, LI Y, WU S, et al. UV-vis-IR irradiation driven CO2 reduction with high light-to-fuel efficiency on a unique nanocomposite of Ni nanoparticles loaded on Ni doped Al2O3 nanosheets[J]. J Mater Chem A,2019,7(34):19800−19810. doi: 10.1039/C9TA06923B [23] ZHAO J, GUO X, SHI R, et al. NiFe nanoalloys derived from layered double hydroxides for photothermal synergistic reforming of CH4 with CO2[J]. Adv Funct Mater,2022,32(31):2204056. doi: 10.1002/adfm.202204056 [24] PADAYACHEE D, MAHOMED A S, SINGH S, et al. Effect of the TiO2 anatase/rutile ratio and interface for the oxidative activation of n-octane[J]. ACS Catal,2020,10(3):2211−2220. doi: 10.1021/acscatal.9b04004 [25] WANG Z, HUANG X, JIA Y, et al. Localized surface plasmon resonance-induced bidirectional electron transfer of formic acid adsorption for boosting photocatalytic hydrogen production on Ni/TiO2[J]. Chem Eng J,2024,482:148942. doi: 10.1016/j.cej.2024.148942 [26] YI X, YANG Y, XU D, et al. Metal–Support Interactions on Ag/Co3O4 Nanowire Monolithic Catalysts Promoting Catalytic Soot Combustion[J]. Trans Tianjin Univ,2022,28(3):174−85. doi: 10.1007/s12209-022-00325-y [27] LU J, ZHANG S, ZHOU H, et al. Ir Single Atoms and Clusters Supported on α-MoC as Catalysts for Efficient Hydrogenation of CO2 to CO[J]. Acta Phys-Chim Sin,2023,39(11):2302021. [28] LI Q, WANG C, WANG H, et al. Disclosing Support-Size-Dependent Effect on Ambient Light-Driven Photothermal CO2 Hydrogenation over Nickel/Titanium Dioxide[J]. Angew Chem,2024,136(10):e202318166. doi: 10.1002/ange.202318166 [29] LIN Y, ZHU Y, PAN X, et al. Modulating the methanation activity of Ni by the crystal phase of TiO2[J]. Catal Sci Technol,2017,7(13):2813−2818. doi: 10.1039/C7CY00124J [30] XU M, QIN X, XU Y, et al. Boosting CO hydrogenation towards C2+ hydrocarbons over interfacial TiO2−x/Ni catalysts[J]. Nat Commun,2022,13(1):6720. doi: 10.1038/s41467-022-34463-7 -
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