Study of the active phase of silver catalysts for ethylene epoxidation

被引：38

作者：

Amorim de Carvalho, Marta C. N.

Passos, Fabio B.

Schmal, M. ^{[1
]}

机构：

[1] Univ Fed Rio de Janeiro, NUCAT, PEQ, COPPE,Chem Engn Program, BR-21941 Rio De Janeiro, Brazil

[2] Univ Fed Fluminense, Dept Chem & Petr Engn, Rio De Janeiro, Brazil

来源：

JOURNAL OF CATALYSIS | 2007年 / 248卷 / 01期

关键词：

silver; ethylene; epoxidation;

D O I：

10.1016/j.jcat.2006.10.030

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

An investigation of ethylene epoxidation on alpha-alumina-supported silver catalysts promoted by cesium found that cesium favored the formation of strongly adsorbed electrophilic oxygen. The reactant mixture (C2H4 and O-2) modified the silver structure, favoring the formation of oxygen electrophilic species. In situ DRIFTS results demonstrated the formation of a thin film of silver for the cesium-promoted catalyst, decreasing the influence of the support. Similar in situ DRS profiles were observed for promoted and nonpromoted catalysts, indicating that the effect of cesium is due mainly to geometric rather than electronic effects. At iso-conversion conditions, Cs presence increased the yield toward ethylene oxide. (C) 2007 Published by Elsevier Inc.

引用

页码：124 / 129

页数：6

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