催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (8): 1424-1429.DOI: 10.3724/SP.J.1088.2011.10236

• 研究论文 • 上一篇    下一篇

不同载体负载的 Cr 基催化剂催化 CO2 氧化异丁烷脱氢制异丁烯

孙果宋 1,2, 黄青则 3, 李会泉 4,a, 柳海涛 4,b, 张钊 4, 王兴瑞 4, 王秋萍 3, 王金淑 1   

  1. 1北京工业大学材料科学与工程学院, 北京 100022; 2广西壮族自治区化工研究院, 广西南宁 530001; 3广西民族大学化学与生态工程学院, 广西南宁 530006; 4中国科学院过程工程研究所绿色过程与工程院重点实验室, 北京 100190
  • 收稿日期:2011-03-10 修回日期:2011-06-02 出版日期:2011-08-05 发布日期:2014-12-26

Different Supports-Supported Cr-Based Catalysts for Oxidative Dehydrogenation of Isobutane with CO2

SUN Guosong1,2, HUANG Qingze3, LI Huiquan4,a, LIU Haitao4,b, ZHANG Zhao4, WANG Xingrui4, WANG Qiuping3, WANG Jinshu1   

  1. 1College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022, China; 2Guangxi Research Institute of Chemical Industry, Nanning 530001, Guangxi, China; 3College of Chemistry and Ecology Engineering, Guangxi University for Nationalities, Nanning 530006, Guangxi, China; 4Key Laboratory for Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2011-03-10 Revised:2011-06-02 Online:2011-08-05 Published:2014-12-26

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摘要： 制备了介孔分子筛 MSU-1, γ-Al2O3, AC (活性炭) 和 MgO 负载的 CrOx 催化剂, 并考察了其催化 CO2 氧化异丁烷脱氢制异丁烯反应性能. 结果表明, 各催化剂活性的顺序为: CrOx/MSU-1 > CrOx/Al2O3 > CrOx/AC > CrOx/MgO. 其中在 CrOx/MSU-1 催化剂上, 异丁烷的转化率和异丁烯的收率分别为 59.2% 和 39.5%. 同时, 利用 N2 吸附-脱附、X 射线衍射、X 射线光电子能谱和程序升温脱附对催化剂进行了表征. 结果表明, 载体的比表面积对相应催化剂的初始活性有一定的影响; 当 CrOx 负载量较低时, 以单层分散于载体上, 且含有较多孤立状态 Cr6+时催化剂的活性更高. 另外, 催化剂表面的弱酸性也会影响其活性; 而碱性位的存在可提高催化剂稳定性.

关键词: MSU-1 分子筛, 铬氧化物, 异丁烷, 二氧化碳, 催化脱氢, 异丁烯

Abstract: The effect of supports (MSU-1, γ-Al2O3, AC (activated carbon), and MgO) on the catalytic activity of Cr-based catalysts was investigated for the dehydrogenation of isobutane with CO2. The catalytic activity was in the order of CrOx/MSU-1 > CrOx/Al2O3 > CrOx/AC > CrOx/MgO. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (TPD). The XRD results indicate that the active species of Cr are dispersed well on the supports. N2 adsorption-desorption shows that the support MSU-1 has the largest surface area (804.2 m2/g), which results in excellent dispersion of Cr and highest activity. The XPS results reveal that Cr6+ is one of the active centers. The results of NH3-TPD indicate that catalyst activity is proportional to the amount of weak acid adsorption sites. As a result, the best support is the MSU-1 zeolite owing to its high specific area and a large amount of weak acid sites. The 59.2% conversion of isobutane and the 39.5% yield of isobutene are achieved on the CrOx/MSU-1 catalyst.

Key words: MSU-1 zeolite, chromium oxide, isobutane, carbon dioxide, catalytic dehydrogenation, isobutene