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partial oxidation of methane to Syngas over Monolithic Ni/γ-Al_2O_3 Catalyst——Effects of Rare Earths and Other Basic Promoters

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Journal of Rare Earths 2006年第4期24卷 451-455页

作者：马迪梅大江李璇龚茂初陈耀强 College of Chemistry Sichuan University Chengdu 610064 China

A series of monolithic Ni/γ-Al2O3 catalysts with and without basic promoters （Na, Sr, La, Ce） were prepared. partial oxidation of methane （POM） to syngas was carried out in a continuous-flow, fixed-bed reactor. The influences of reaction conditions, including temperature, CH4/O2 ratio and space velocity, on the performance of the catalyst were investigated. The results show that at a high space velocity of 1 ×10^5 h^-1, optimal CH4 conversion can be obtained. Effects of promoters such as Na, Sr, Ce, La were also investigated, and the catalyst samples were characterized by means of temperature-programmed reduction and XRD techniques. XRD suggests that the addition of promoters has no influence on the crystal structure of Ni/γ-Al2O3 catalyst. The results show that the addition of a small amount of promoters improves the reducibility and activity of the catalyst. The side reaction CH4 ＋ 2O2→CO2 ＋ H2O, is fully restrained and 100% H2 selectivity is achieved when Ce and La are used as promoters, respectively.

关键词： promoter partial oxidation of methane syngas monolithic rare earths

partial oxidation of methane by photocatalysis

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Chinese Chemical Letters 2024年第1期35卷 153-168页

作者： Zhongshan Yang Qiqi Zhang Hui Song Xin Chen Jiwei Cui Yanhui Sun Lequan Liu Jinhua Ye TJU-NIMS International Collaboration Laboratory School of Materials Science and EngineeringTianjin UniversityTianjin 300072China International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials Science(NIMS)1-1 NamikiIbaraki 3050047Japan Zhejiang LAMP Co. Ltd.Wenzhou 325206China

methane chemistry is one of the“Holy Grails of catalysis”.It is highly desirable but challenge to transform methane into value-added chemicals,because of its high C-H bonding energy(435 kJ/mol),lack ofπbonding or unpaired ***,commercial methane conversion is usually carried out in harsh conditions with enormous energy *** partial oxidation of methane to liquid oxygenates(PPOMO)is a future-oriented technology towards realizing high efficiency and high selectivity under mild *** selection of oxidant is crucial to the PPOMO ***,attentions are paid to the research progress of PPOMO with various oxidants(O_(2),H_(2)O,H_(2)O_(2)and other oxidants).Moreover,the activation of the selected oxidants is also highly ***,we summarized the methane activation mechanisms focusing on the C-H bond that was broken mainly by·OH radical,O-specie or photogenerated hole(h+).Finally,the challenges and prospects in this subject are briefly discussed.

关键词： partial oxidation of methane Photocatalysis Liquid oxygenates Oxidants C-H activation

Effect of heat transfer on the oscillatory behavior in partial oxidation of methane over nickel catalyst

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Journal of Natural Gas Chemistry 2011年第5期20卷 503-506页

作者： Xiubin Ren Xiangyun Guo .CollegeofChemistryandChemicalEngineering Xi＇anUniversityofScienceandTechnologyXi＇an710054ShaanxiChina StateKeyLaboratoryofCoalConversion InstituteofCoalChemistryChineseAcademyofSciencesTaiyuan030001ShanxiChina

Monte Carlo method was applied to simulate the oscillatory behavior during partial oxidation of methane under non-isothermal condition. The simulation was performed to examine the influences of heat transfer constant and particle size on the kinetic oscillation. The oscillatory period and amplitude were observed to increase with the increase of heat transfer constant. The increase of catalyst particle size was found to result in short oscillatory period and more or less regular oscillations combined with the formation of oxide down to L = 100.

关键词： Monte Carlo simulation oscillation partial oxidation of methane heat transfer

Effect of CeO_2 and CaO Promoters on Ignition Performance for partial oxidation of methane over Ni/MgO-Al_2O_3 Catalyst

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Journal of Natural Gas Chemistry 2007年第2期16卷 148-154页

作者： Yejun Qiu Jixiang Chen Jiyan Zhang Department of Catalysis Science and Engineering School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

The effect of CeO2 and CaO promoters on the ignition performance over Ni/MgO-Al2O3 catalyst for the partial oxidation of methane （POM） to synthesis gas was investigated. It was found that the POM reaction could not be ignited over lwt%Ni/MgO-Al2O3 catalyst without the promoters in the temperature range from 773 K to 1073 K. CeO2 and CaO promoters enhanced the ignition performance and the POM reactivity of lwt%Ni/MgO-Al2O3 catalyst remarkably. Moreover, the improving effect became greater with the increase of the promoter content under the investigated reactiorrconditions. The modification effects of CeO2 and CaO promoters were closely related to the concentration and reducibility of the surface and bulk oxygen species.

关键词： partial oxidation of methane synthesis gas nickel-based catalyst ignition cerium oxide calcium oxide

Effect of Cu promoter on Ni-based SBA-15 catalysts for partial oxidation of methane to syngas

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Journal of Natural Gas Chemistry 2009年第4期18卷 392-398页

作者： Fabien Habimana Xiujin Li Shengfu Ji Bao Lang Daoan Sun Chengyue Li State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China Department of Environmental Engineering Beijing University of Chemical Technology Beijing 100029 China

A series of Ni/SBA-15 catalysts with 5wt% to 15wt% Ni content as well as a series of 12.5%Ni/Cu/SBA-15 catalysts with 1% to 10% copper content were prepared by the impregnation method. The catalytic performance for partial oxidation of methane was investigated in a continuous flow microreactor under atmospheric pressure. The textural and chemical properties of the catalysts were characterized by XRD, TEM, BET and Hz-TPR techniques. The results indicated that the catalysts modified with Cu promoter showed better performance than those without modification. For the 12.5%Ni/2.5%/Cu/SBA-15 catalyst, at 850 ℃ the conversion of CH4 reached 97.9% and the selectivity of CO and H2 reached 98.0% and 96.0%, respectively. In XRD patterns of the Ni/Cu/SBA-15 catalyst with 7.5 to 10% Cu contents there were CuO characteristic peaks beside NiO characteristic peaks. The mesoporous structure of SBA-15 was retained in all of the catalysts. TPR analysis of the catalysts revealed that a strong interaction between Ni, Cu promoter and SBA-15 support may be existed. This interaction enhanced significantly the redox properties of the catalysts resulting in the higher catalytic activity.

关键词： Cu promoter Ni-based catalyst SBA-15 methane partial oxidation of methane

Investigation on the Performance of Supported Molybdenum Carbide for the partial oxidation of methane

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Journal of Natural Gas Chemistry 2003年第1期12卷 23-30页

作者： Quanli Zhu, Jian Yang, Jiaxin Wang, Shengfu Ji, Hanqing WangState Key Laboratory for Oxo Synthesis and Selective oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China Stt. Key Lab. Oxo Synth./Sel. Oxid. Lanzhou Inst. of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

The performance of supported and unsupported molybdenum carbide for thepartial oxidation of methane (POM) to syngas was investigated. An evaluation of the catalystsindicates that bulk molybdenum carbide has a higher methane conversion during the initial stage buta lower selectivity to CO and H_2/CO ratio in the products. The rapid deactivation of the catalystis also a significant problem. However, the supported molybdenum carbide catalyst shows a muchhigher methane conversion, increased selectivity and significantly improved catalytic stability. Thecharacterization by XRD and BET specific area measurements depict an improved dispersion ofmolybdenum carbide when using alumina as a carrier. The bulk or the supported molybdenum carbideexists in the β-MO_2C phase, while it is transformed into molybdenum dioxide postcatalysis which isan important cause of molybdenum carbide deactivation.

关键词： molybdenum carbide molybdenum oxide partial oxidation of methane syngas deactivation

DEACTIVATION STUDIES ON NiO/γ-Al2O3 CATALYST FOR partial oxidation OF methane TO SYNGASInfluence of Sol-Gel Method on Catalytic Performance

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Chinese Journal of Catalysis 1999年第4期 10-11页

作者： Zhang Yuhong, Xiong Guoxing, Liu Shenglin, Sheng Shishan, Yang Weishen (State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics,The Chinese Academy of Sciences, Dalian 116023)

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关键词： nickelbased catalyst partial oxidation of methane syngas deactivation solgel method

Studies of Catalysis in partial oxidation of methane to Syngas（Ⅱ）──Chemisorbed Species，Energetics and Mechanism

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Chemical Research in Chinese Universities 1995年第4期11卷 323-335页

作者： CHEN Ping ZHANG Hong-bin LIN Guo-dong andTSAI Khi-rui(Department of Chemistry &State Key Laboratory for Physical Chemistyry of the Solid Surface ,Xiamen University ,Xiamen 361005)

he characteristic study,by means of in-situ IR spectroscopy, of chemisorbed species on the Ni-catalysts for the partial oxidation of methane(POM)to syngas demonstrated the existence of CH_x(a)and H_xCO(a)adspecies on the functioning Ni-catalysts, Several designed experimental investigations on the reactivities of methane with CO_2 and with O_2,respectively,over the Ni-catalysts, and of CO_2 with the prereduced Ni-catalyst,ats well as of the deposited carbon with CO_2 and with O_2,respectlvely,liave been carried out and the reLqults were unfavorable to the two-step mechanistic interpretation proposed for the POM reaction. By means of tlie BOC-MP Approach,energetics of a set of elementary reactions,which may be involved in the POM process,on the clean(111)surface of Ni,Fe,Cu and Pd, re- spectively,has been *** result;of the experiments and the calculation of the present work favor the direct catalytic dissociation-plus-surface oxidation-plus-further debdrogenation mechanism as the dominant pathway making major contribution to the POM reaction.

关键词： partial oxidation of methane Syngas Chemisorbed species Energetics. Mechanism

PROMOTING EFFECT OF RARE EARTH OXIDES ON Ni/RexOy-Al2O3 CATALYST FOR partial oxidation of methane TO SYNTHESIS GAS

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Journal of Energy Chemistry 1997年第2期 93-100页

作者： YAN Qian-Gu YU Zuo-Long (Chengdu Institute of Organic Chemistry, The Chinese Academy of Sciences Chengdu, Sichuan 610041)YUAN Song-Yue (Changchun Institute of Applied Chemistry, The Chinese Academy of Sciences Changchun, Jilin 130022)

partial oxidation of methane to synthesis gas over Ni/Al2O3 and Ni/RExOy-Al2O3 (RExOy is rare earth oxide such as Y2O3, La2O3 and CeO2) catalysts were investigated by using powder X-ray diffraction. The catalytic activity, variation of nickel crystallite size, stability and carbon deposition of catalyst were examined. The presence of rare earth oxides in Ni/Al2O3 catalyst results in a great improvement on the stability of catalyst through interaction between active component Ni and rare earth oxides. The interaction suppresses the growth and the migration of Ni grains. It was found that carbon deposition on Ni/RExOy-Al2O3 catalysts were suppressed and decreased, meantime the catalysts, especially Ni/CeO2-Al2O3, remained activities for partial oxidation of methane. The model of interaction between Ni grains and rare earth oxides may mainly be the embedment, and for Ni/CeO2-Al2O3, there may be a redox circle mechanism of CeO2 besides the embedment.

关键词： partial oxidation of methane synthesis gas Ni/Al2O3 catalyst rare earth oxides