多组分氧化物Ag－Bi－V－Mo－O催化作用的光电子能谱研究

An Investigation of Redox Mechanism of Scheelite-type Multicomponent oxide Ag-Bi-V-Mo-O by XPS Spectra

多组分氧化物Ａｇ－Ｂｉ－Ｖ－Ｍｏ－Ｏ催化作用的光电子能谱研究宋伟，李静，窦伯生（中国科学院长春应用化学研究所长春１３００２２）关键词 钼钒酸铋，助剂Ａｇ，ＸＰＳ，Ａｒ~＋刻蚀，氧化还原对于烃类选择氧化反应中复合氧化物的催化作用，普遍认为是Ｒｅｄｏｘ机...

The redox behavior of Ag-doped bismuth vanadomolybdate catalysts and promotion of catalysis by Ag+ have been investigated by XPS in situ Ar+ ion etching. The results of XPS show that Mo6+ cation is the site on which hydrocarbons absorb and Bi3+ cation is responsible for converting molecular oxygen into lattice oxide ion. In the reaction process. Mo6+ cation is reduced by hydrocarbons and Bi3+ cation is oxidized by molecular oxygen. The V5+ cation is involved in diffusing O2- and transferring electrons into the bulk of catalysts. Ag+-promoter is conducive to forming lattice oxide ions frorn molecular oxygen and increasing the reoxidation speed on the position of Bi3- cation.