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Performance of Methanol-to-Olefins Catalytic Reactions by the Addition of PEG in the Synthesis of SAPO-34

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Transactions of Tianjin University 2017年第6期23卷 501-510页

作者： Yaquan Wang Zhao Wang Chao Sun Hengbao Chen Hongyao Li Haoyang Li Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

SAPO-34, a silicoaluminophosphate zeolite, has been synthesized by the hydrothermal method with the addition of different molecular weights of polyethylene glycol (PEG), and has been characterized with XRD, SEM, N2adsorption–desorption, FT-IR, and NH3temperature-programmed desorption (NH3-TPD). We studied SAPO-34 as a catalyst in the methanol-to-olefins (MTO) reaction, in a fixed-bed reactor. The results show that the chain length of PEG has a great influence on the particle size and morphology of SAPO-34. PEG acts as inhibitor in the crystallization process. With the increase of the chain length of PEG used in the synthesis, from a relative molecular weight of 400–6000, the morphology of SAPO-34 changes gradually from cubic to nanoplate-like and then changes to cubic again. The particle size decreases markedly at first and then increases to some extent. The catalytic stability in the MTO reaction also increases first and then decreases, with all the catalysts having almost the same selectivity to olefins. When the sample is synthesized with PEG800, the particles become nanoplate-like with a thickness of 46 nm on average, and the catalytic stability is appreciably prolonged, which is attributed to the shorter diffusion paths of the reactants in the zeolite. © 2017 The Author(s)

关键词： Catalysis catalyst selectivity catalysts Chain length Chains Desorption Methanol Molecular weight Nanostructures Olefins Particle size Polyethylene glycols Polyethylenes Zeolites

碳化镍钼催化剂的制备及其甲烷干气重整活性(英文)

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催化学报 2011年第5期32卷 771-776页

作者： Taro HIROSE Yasushi OZAWA Masatoshi NAGAI Graduate School of Bio-Applications and Systems Engineering Tokyo University of Agriculture and Technology Energy Engineering Research Laboratory Central Research Institute of Electric Power Industry

Nickel molybdenum carbide catalysts were prepared and their activities in the CO2 reforming of methane at a low CO2/CH4 reactant ratio were investigated using a microreactor at atmospheric pressure and at 973 *** effect of the catalyst preparation method and the Ni/Mo ratio on the increase in catalyst life and the promotion of catalytic activity were investigated using N2 adsorption,X-ray diffraction, temperature-programmed carburization,temperature-programmed reaction,and a reforming *** 25Ni75Mo catalyst that was carburized at 813 K exhibited the highest hydrogen formation ability and gave the least carbon *** incomplete carburization of the Mo oxide species in the catalyst that was carburized at a lower temperature gradually gave a more active carburized *** NiMoOxCy in the catalyst was more active in hydrogen formation during the dry reforming of methane whileβ-Mo2C andη-Mo3C2 were less active.

关键词： catalyst activation catalyst selectivity fuel dry reforming methane

Promoted catalytic performances of highly dispersed V-doped SBA-16 catalysts for oxidative dehydrogenation of ethane to ethylene

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Journal of Energy Chemistry 2016年第4期25卷 577-586页

作者： Lian Kong Jianmei Li Qinglong Liu Zhen Zhao Qianyao Sun Jian Liu Yuechang Wei State Key Laboratory of Heavy Oil Processing China University of Petroleum Institute of Catalysis for Energy and Environment Shenyang Normal University

V-doped SBA-16 catalysts (V-SBA-16) with 3D nanocage mesopores have been successfully synthesized by a modified one-pot method under weak acid condition. The obtained materials were characterized by means of small angle XRD, N2adsorption–desorption, TEM, UV–Vis and UV-Raman spectroscopy. These characterization results indicated that well-order mesoporous structures were maintained even at higher vanadium loadings and high concentration of VOxspecies were incorporated into the framework of SBA-16 support. The catalytic performances of V-SBA-16, V/SBA-16 and V/SiO2catalysts were comparatively investigated for the oxidative dehydrogenation of ethane to ethylene. The highest selectivity to ethylene of 63.3% and ethylene yield of 25.6% were obtained over 1.0V-SBA-16 catalyst. The superior catalytic performance of V-SBA-16 catalysts could be attributed to the presence of isolated framework VOxspecies, the unique structure of SBA-16 support and weak acidity. Moreover, V/SiO2catalyst exhibited relatively poor catalytic activity duo to the formation of V2O5nanoparticles on the surface of SiO2support and the low dispersion of VOxspecies. These results indicated that the catalytic performances of the studied catalysts were strongly dependent on the vanadium loading, the nature and neighboring environment of VOxspecies and the structure of support. © 2016

关键词： catalyst selectivity catalysts Dehydrogenation Ethane Ethylene Vanadium

Fischer–Tropsch synthesis on impregnated cobalt-based catalysts:New insights into the effect of impregnation solutions and pH value

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Journal of Energy Chemistry 2016年第6期25卷 994-1000页

作者： Chuang Xing Peipei Ai Peipei Zhang Xinhua Gao Ruiqin Yang Noriyuki Yamane Jian Sun Prasert Reubroycharoen Noritatsu Tsubaki School of Biological and Chemical Engineering Zhejiang University of Science and Technology Department of Applied Chemistry Graduate School of Engineering University of Toyama Advanced Technology Research 20-1 Laboratories Nippon Steel & Sumitomo Metal Corporation Dalian National Laboratory for Clean Energy (DNL) Dalian Institute of Chemical Physics Chinese Academy of Sciences Department of Chemical Technology Faculty of Science Chulalongkorn University

The Co-based catalysts were prepared with different cobalt acetate solutions. Effects of pH value were studied deeply on Fischer–Tropsch synthesis (FTS) through a semi-batch reactor. Among all impregnation solutions (water, butanol, amyl alcohol, acetic acid, nitric acid and ammonium nitrate), the catalyst prepared by NH4NO3solution showed the highest catalytic activity due to its small particle size and high reduction degree. However, the catalyst with the smallest particle size derived from water as impregnation solution exhibited low activity as well as high methane selectivity since it was difficult to be reduced and inactive in FTS. According to FT-IR spectra results, the low intensity of absorbed CO on the catalyst prepared from water solution resulted in low FTS activity. Whereas, the high activity of catalysts prepared from NH4NO3solution could be explained by the high intensity of absorbed CO on the catalysts. The cobalt species on the catalysts prepared under lower pH conditions exhibited smaller particle size distribution as well as lower CO conversion than those prepared at higher pH value. © 2016 Science Press

关键词： Batch reactors catalyst selectivity catalysts Cobalt Impregnation Particle size Particle size analysis pH pH effects