物理化学学报 >> 1996, Vol. 12 >> Issue (12): 1074-1078.doi: 10.3866/PKU.WHXB19961205

研究论文 上一篇    下一篇

ZrO2催化剂表面Zr3+离子与F-T反应中异丁烯选择性的相关性

李文,殷元骐,冯良波,郑培菊   

  1. 中国科学院兰州化学物理研究所,兰州 730000|复旦大学分析测试研究中心,上海 200433
  • 收稿日期:1996-03-11 修回日期:1996-07-29 发布日期:1996-12-15
  • 通讯作者: 李文

Correlation Between the Catalytic Property and Zr3+ Ion for ZrO2 in F-T Reaction

Li Wen,Yin Yuan-Qi,Feng Liang-Bo,Zheng Pei-Ju   

  1. Lanzhou Institute of Chemical Physics,Chinese Academy of Science,Lanzhou 730000|Research Center of Analysis and Measurement,Fudan University,Shanghai 200433
  • Received:1996-03-11 Revised:1996-07-29 Published:1996-12-15
  • Contact: Li Wen

摘要:

研究了ZrO2催化剂体系中的CO加氢反应,并对催化剂的使用前后以及特殊处理催化剂进行了EPR表征. 在使用前催化剂中观测到了一个较强的EPR信号g⊥=1.976和g||=1.961,并指认为来自ZrO2表面的Zr3+离子,而F-T反应评价后催化剂均给出了唯一较强和尖锐的信号g=2.0024并指认为来自催化剂表面的解离H原子.通过进一步的EPR表征,结果均显示Zr3+离子可能参与了反应过程.定量研究表明,催化剂表面Zr3+离子浓度与反应中异丁烯的选择性有一近似的线性关系. 最后,推测了依其表面物种Zr(Ⅲ)(CO)2形成异丁烯的可能催化机理.

关键词: EPR, ZrO2催化, Zr3+离子

Abstract:

CO hydrogenation was studied over zirconia catalysts. The catalysts, which were classed into three types of samples-the fresh, used and specially treated catalysts, were characterized by means of EPR spectroscopy. A strong signal at g⊥=1 .976 and g||=1.961, which was assigned to Zr3+ ion on the surface of ZrO2, was observed for the fresh catalysts. In contrast, unique strong and sharp signal at g=2.0024, which was assigned to dissociated H atom, also was observed for the used catalysts. Further verification of the assignments was carried out by EPR characterization of the specially treated catalysts. These results show that Zr3+ ion might involve in CO hydrogenation. Quantitative studies reveal that there is a close linear relation between Zr3+ ion and the selectivity to isobutene for the reaction over ZrO2. Finally, a possible mechanism of the catalytic reaction via a surface species Zr(Ⅲ)(CO)2 was proposed.

Key words: EPR spectra, ZrO2 catalyst, Zr3+ ion