贵金属对NM/WO3-ZrO2(NM=Ru,Rh和Pd)催化乙烯直接氧化制乙酸反应的影响(英文)  

Influence of Noble Metals on the Direct Oxidation of Ethylene to Acetic Acid over NM/WO_3-ZrO_2 (NM = Ru, Rh, and Pd) Catalysts

作　　者：王丽霞[1,2] 徐庶亮[1,2] 楚文玲[1] 杨维慎[1] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023 [2]中国科学院研究生院,北京100049

出　　处：《催化学报》2009年第12期1281-1286,共6页

基　　金：Supported by the National Science Foundation for Distinguished Young Scholars (20725313);the National Basic Research Program of China (973 Program, 2005CB221404)

摘　　要：研究了负载Ru,Rh和Pd的WO3-ZrO2催化剂在乙烯直接氧化制乙酸反应中的催化性能.结果显示,负载的贵金属对催化剂的催化性能有非常重要的影响.Rh/WO3-ZrO2催化剂具有最高的乙烯转化率,而Ru/WO3-ZrO2催化剂对反应几乎没有活性.H2化学吸附结果显示,高的催化性能来源于高的金属分散度.Pd/WO3-ZrO2催化剂显示了最高的乙酸选择性(75%),而其它两个催化剂的乙酸选择性都非常低(～10%).程序升温氧化和程序升温还原结果显示,贵金属–O键的键强对产物的选择性具有重要的影响.弱的贵金属–O键可以通过将氧插入到乙烯和/或乙醛中而有利于乙酸的生成,而强的贵金属–O键会导致乙烯完全氧化为COx.Ru-, Rh-, and Pd/WO3-ZrO2 catalysts were studied for the direct oxidation of ethylene to acetic acid. The catalytic activity and selectivity depended strongly on the noble metals used. Rh/WO3-ZrO2 gave the highest conversion of ethylene, whereas Ru/WO3-ZrO2 was almost inactive. The higher catalytic activity was attributed to a better metal dispersion. Pd/WO3-ZrO2 gave the highest selectivity for acetic acid （75%）, with the selectivity of the other two catalysts being rather low （～10%）. Temperature-programmed oxidation and H2 reduction experiments were used to show that the strength of the noble metal-oxygen bond played an important role in product distribution. A weak metal--oxygen bond favored the formation of acetic acid, while a strong metal-oxygen bond favored the combustion of ethylene to COx.

关 键 词：乙烯 氧化 乙酸 氧化钨 氧化锆 钯 钌 铑 

分 类 号：TQ225.122[化学工程—有机化工]