高等学校化学学报

高等学校化学学报 ›› 1990, Vol. 11 ›› Issue (2): 168.

• 研究论文 • 上一篇    下一篇

Mo-Bi-Ce/SiO2催化剂的XPS研究

郭沁林1, 桂琳琳1, 俞启全2, 金韵2   

  1. 1. 北京大学物理化学研究所;
    2. 北京大学化学系
  • 收稿日期:1988-05-03 出版日期:1990-02-24 发布日期:1990-02-24
  • 通讯作者: 桂琳琳

Application of XPS to investigating Mo-Bi-Ce/SiO2 Catalyst

Guo Qingling1, Gui Linlin1, Yu Qiquan2, Jin Yun2   

  1. 1. Institute of Physical Chemistry, Peking University, Beijing;
    2. Department of Chemistry, Peking University, Beijing
  • Received:1988-05-03 Online:1990-02-24 Published:1990-02-24

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摘要： 用XPS研究了甲醇还原前后的Mo-Bi-Ce/SiO2催化剂并进行了测定。结果表明,反应前催化剂表面主要由Bi2(MoO4)3与CeO2组成,而反应后Ce4+还原为Ce0并出现少量Ce2O3,同时Bi、Mo均还原为低价态,还原顺序为Ce、Bi、Mo。还原前Bi处于催化剂表层,反应过程中扩散进入体相,再经氧脉冲氧化Bi迁回表层。活性组份被氧化的顺序为Mo、Bi、Ce。

关键词: 电子能谱, Mo-Bi-Ce/SiO2催化剂, 甲醇还原

Abstract: Mo-Bi-Ce/SiO2 has been investigated by XPStechnique before and after reduction with mathanol. The result shows that the catalyst consists of Bi12(MoO4)3 and CeO2 before reduction, and after reduction with mathanol Ce4+ reduces to Ce0 with a small amount of Ce2O3 and Bi, Mo reduces to lower valence state. The sequence of reduction is Ce, Bi, Mo. Before reduction Bi resides at the external layer in the catalyst and then diffuses into internal layer during reduction. The reduced catalyst re-oxidized with oxygen in pulse experiment shows that all of active components are reoxidized and the sequence of oxidation is Mo, Bi, Ce. Bi migrates back to surface during reoxidation.

Key words: XPS, Mo-Bi-Ce/SiO2 catalyst, Reduction of methanol

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