波谱学杂志 ›› 1990, Vol. 7 ›› Issue (3): 305-312.

• 研究论文 • 上一篇    下一篇

载体钒氧化物中钒-吸附物分子相互作用的ESR研究

詹瑞云, 刘雅言, 刘桂珍   

  1. 中国科学院长春应用化学研究所
  • 收稿日期:1989-09-04 修回日期:1989-11-04 出版日期:1990-09-05 发布日期:2018-01-23

AN ESR STUDY OF VANADIUM-ADSORBATE INTERACTION ON SUPPORTED VANADIUM OXIDE CATALYST

Zhan Ruiyun, Liu Yayan, Liu Guizhen   

  1. Changchun Institute of Applied Chemistry, Academa Sinica, Changchun
  • Received:1989-09-04 Revised:1989-11-04 Online:1990-09-05 Published:2018-01-23

摘要: 电子自旋共振技术已经用来研究还原态V2O5/SiO2催化剂和各种吸附分子的相互作用。实验指出:具有四面体配位结构的V4+离子是活性中心,V4+和CH2OH,HCl,CH3CN分子的相互作用导致形成八面体配位结构的表面VO2+络合物,它们的ESR和成键参数计算指出不成对电子主要定位在钒离子的d轨道上。77 K下吸附O2分子已经观察到氧自由基的ESR信号,但吸附乙烯和丙烯不能改变V4+离子的配位结构。

关键词: ESR, V2O5/SiO2催化剂, 吸附作用, 氧-钒络合物, 氧自由基

Abstract: ESR technique has been used to study the interaction of reduced V2O5/SiO2 catalyst with a variety of adsorbed molecules. It has been shown that the V4+ ions with tetrahedral coordination are active centers. Their interaction with adsorbed molecules, such as CH3OH, HCl, and CH3CN etc, leads to the formation of octahedrally coordinated VO2+ complexes on the surface of the catalyst. The calculation of bonding parameters of surface complexes formed indicates that the unpaired electron is mostly confined to the vanadium ions d-orbital. The adsorption of oxygen at 77 K leads to the formation of various oxygen radicals. But no change had been found for the coordinated state of V4+ ions after adsorption of ethylene or propylene molecules.

Key words: ESR, V2O5/SiO2 catalyst, adsorption, vanadyl complexes, oxygen radical species