催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (8): 1370-1375.DOI: 10.3724/SP.J.1088.2011.10319

• 研究论文 • 上一篇    下一篇

SBA-15 的孔壁碳膜修饰对钴基催化剂结构与催化性能的影响

朱海燕 1,2,*, 周朝华 1, 马兰 1, 程振兴 1, 沈俭一 2   

  1. 1 防化指挥工程学院三系, 北京 102205; 2 南京大学化学化工学院, 江苏南京 210093
  • 收稿日期:2011-03-16 修回日期:2011-04-11 出版日期:2011-08-05 发布日期:2014-12-26

Effect of Modification of SBA-15 by Carbon Films on Textural and Catalytic Properties of Supported Cobalt Catalysts

ZHU Haiyan1,2,*, ZHOU Chaohua1, MA Lan1, CHENG Zhenxing1, SHEN Jianyi2   

  1. 1The No. 3 Department, Institute of Chemical Defence, Beijing 102205, China; 2School of Chemical and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2011-03-16 Revised:2011-04-11 Online:2011-08-05 Published:2014-12-26

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820

被引次数

7

摘要： 在惰性气体中焙烧 SBA-15 制得孔壁被碳修饰的 SBA-15C 样品, 以它和 SBA-15 为载体, 采用等量浸渍法制备了负载型 Co 基催化剂, 并运用 X 射线衍射、N2 物理吸附、程序升温还原、NH3 吸附量热等手段对样品进行了表征. 结果表明, SBA-15C 仍保持原有的六方有序的中孔结构, 但其孔壁经碳修饰后发生增厚, 比表面积略有下降. Co 的负载使得 SBA-15 和 SBA-15C 样品的孔径基本不变, 但比表面积和孔体积下降, 仍保持其中孔分子筛的特征. Co3O4 在 SBA-15C 上的晶粒较小, 但还原度较低, 表明碳的存在有利于 Co 物种的分散. 比较了 Co/SBA-15 和 Co/SBA-15C 上的费托合成反应性能, 发现两者对 C5+ 的选择性均较高 (达 80% 左右), 但 Co/SBA-15C 催化剂稳定性优于 Co/SBA-15.

关键词: SBA-15 分子筛, 孔壁碳修饰, 钴基催化剂, 费托合成

Abstract: Carbon coated mesoporous SBA-15, named SBA-15C, was obtained from as-synthesized SBA-15 after graphitization in inert gas. With SBA-15 and SBA-15C as supports and cobalt nitrate aqueous solution as precursor, the supported cobalt-based catalyst samples were prepared by a wet impregnation method. The catalyst samples were characterized by X-ray diffraction, N2 physisorption, temperature-programmed reduction, and NH3 microcalorimetric adsorption. The results suggested that upon doping the inner walls of SBA-15 with carbon, the hexagonal ordered mesoporous framework was retained while the surface area decreased a little and the thickness of pore wall increased. The supported cobalt-based catalyst retained the mesoporous characteristics with decreased surface area and pore volume. The average particle size of Co3O4 on SBA-15C was smaller than that on SBA-15, which suggested that the existence of carbon improved the dispersion of Co3O4 particles. However, the modification of SBA-15 with carbon films did not seem to increase the reducibility of Co3O4. Both Co/SBA-15 and Co/SBA-15C exhibited high selectivity for C5+ hydrocarbons (~80%), but Co/SBA-15C showed higher stability in the F-T synthesis reactions.

Key words: SBA-15 zeolite, pore wall modification, cobalt-based catalyst, Fischer-Tropsch synthesis