催化学报

催化学报 ›› 2014, Vol. 35 ›› Issue (1): 8-20.DOI: 10.1016/S1872-2067(12)60723-2

• 研究论文 • 上一篇    下一篇

Ni/CeO2-SiO2催化剂的制备、表征及其甲烷部分氧化制合成气性能

胡久彪a, 余长林a, 毕亚东b, 魏龙福a, 陈建钗a, 陈喜蓉a   

  1. a 江西理工大学冶金与化学工程学院, 江西赣州 341000;
    b 天津理工大学化学化工学院, 天津 300384
  • 收稿日期:2013-07-23 出版日期:2013-12-23 发布日期:2014-01-17
  • 通讯作者: 余长林, 毕亚东
  • 基金资助:

    国家自然科学基金（21067004，21263005，21003095）；江西省教育厅科技基金（GJJ12344）；江西省青年科学家培养对象计划（20122BCB23015）；江西省自然科学基金青年科学基金计划（20133BAB21003）

Preparation and characterization of Ni/CeO2-SiO2 catalysts and their performance in catalytic partial oxidation of methane to syngas

Jiubiao Hua, Changlin Yua, Yadong Bib, Longfu Weia, Jianchai Chena, Xirong Chena   

  1. a School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China;
    b School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, China
  • Received:2013-07-23 Online:2013-12-23 Published:2014-01-17
  • Contact: Changlin Yu, Yadong Bi
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21067004, 21263005, 21003095), Science and Technology Foundation of Jiangxi Provincial Department of Education (GJJ12344), Program of Jiangxi Provincial Young Scientists Cultivating Object (20122BCB23015), and Young Science and Technology Project of Jiangxi Province Natural Science Foundation (20133BAB21003).

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摘要：

以硝酸亚铈（Ce（NO3）3·6H2O）和正硅酸四乙酯（C8H20O4Si）为前驱体，采用溶胶-凝胶法合成了系列具有大比表面积的xCeO2-（1-x）SiO2（x = 0，0.25，0.50，0.75，1）复合氧化物载体，然后浸渍活性组分Ni制得用于甲烷部分氧化制合成气的Ni催化剂。运用N2物理吸附-脱附、X射线粉末衍射、扫描电镜、紫外-可见漫反射光谱、氢程序升温还原、氨程序升温脱附和热重等手段对所得催化剂的组织结构、还原性、表面酸性和积炭行为等进行了表征；同时考察了催化剂的组成、焙烧温度和反应时间等对催化剂在甲烷部分氧化制合成气中催化性能的影响。表征结果表明，该系列Ni/CeO2-SiO2催化剂具有大比表面积，CeO2晶粒较小，NiO的分散性好且易被还原，表面酸性弱，不容易积炭。当Ce/Si摩尔比为1：1，活性组分Ni的质量分数为10%，焙烧温度为700℃时，所制备的Ni/CeO2-SiO2催化剂表现出较好的稳定性、最高的CH4转化率（~84%）和对产物CO及H2的选择性（>87%）。

关键词: 溶胶-凝胶法, 铈-硅复合氧化物, 负载型镍催化剂, 甲烷部分氧化, 合成气

Abstract:

Hexahydrated cerium(Ⅲ) nitrate (Ce(NO3)3·6H2O) and tetraethyl orthosilicate (C8H20O4Si) were used as the precursors for the synthesis of a series of xCeO2-(1-x)SiO2 (x = 0, 0.25, 0.5, 0.75, 1) composite oxides using a sol-gel process under acidic conditions. The active component, Ni, was loaded on the as-synthesized composite oxides, producing supported Ni catalysts for catalytic partial oxidation of methane to syngas. The properties of the as-synthesized products, such as textural structure, reduction behavior, surface acidity, and carbon deposition, were determined using N2 physical adsorption/desorption, X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, temperature-programmed reduction by H2, temperature-programmed desorption of NH3, and thermogravimetric analysis. The effects of catalyst composition, calcination temperature, and reaction time on the catalytic performance were investigated. The characterization results showed that these Ni/CeO2-SiO2 catalysts have large surface area, small CeO2 crystals, weak acidity, and low carbon deposition. Highly dispersed NiO is present and is easy to be reduced. The Ni/CeO2-SiO2 catalyst with a Ce/Si molar ratio of 1:1, w(Ni) = 10%, and calcined at 700℃ exhibited good stability and the highest CH4 conversion (~84%) and CO and H2 selectivity (> 87%).

Key words: Sol-gel process, Ceria-silica composite oxide, Supported nickel catalyst, Partial oxidation of methane, Syngas