CO低温氧化AU/AL_2O_3催化剂的失活及稳定性  

Deactivation and Stability of Au/Al_2O_3 Catalyst for CO Low-Temperature Oxidation

作　　者：邹旭华[1] 齐世学[2] 索掌怀 安立敦[2] 李峰[1] 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,北京100029 [2]烟台大学应用催化研究所,山东烟台264005

出　　处：《催化学报》2006年第2期161-165,共5页

基　　金：国家自然科学基金(20473070);山东省优秀中青年科学家科研奖励基金(03BS076)资助项目

摘　　要：采用改进的等体积浸渍法制备了1.5%AU/AL2O3催化剂,考察了催化剂在CO低温氧化反应中的催化活性,比较了其在干燥的原料气和水汽饱和的原料气中的稳定性,考察了经水汽饱和或加热的空气处理后催化剂活性的变化,探讨了催化剂失活的原因.结果表明,AU/AL2O3在水汽饱和的原料气中比在干燥的原料气中具有更好的稳定性,经水汽饱和或加热的空气处理后其活性均会下降.AU/AL2O3的失活主要包括CO氧化失活、热处理失活和水汽处理失活,前两种失活主要是因为催化剂中类似碳酸盐物种的生成和活性位上-OH的脱除,是可逆失活;而最后一种失活是不可逆的,主要归因于金颗粒的长大.The 1.5 % Au/Al2O3 catalyst was prepared by a modified iso-volume impregnation method, and its catalytic activity for CO low-temperature oxidation was investigated. The long-time catalytic stability of the catalyst in dry reactant gas and reactant gas saturated with water vapor was compared. In addition, the activity changes of the catalyst after treatment in air saturated with water vapor or in air heated above 100℃ were examined, and the reasons for the catalyst deactivation were discussed. The results show that the Au/Al2O3 catalyst exhibits better stability in reactant gas saturated with water vapor than in dry reactant gas. Treatment either in air saturated with water vapor or in air heated above 100℃ may cause catalyst deactivation. There are three main kinds of deactivation for the Au/Al2O3 catalyst： CO OXidation deactivation, thermal treatment deactivation, and water vapor treatment deactivation. The former two are reversible and may be caused by the accumulation of carbonate-like species during CO oxidation or by the removal of -OH ligands in active sites. The growth of gold particles may be responsible for the last kind of deactivation which is irreversible.

关 键 词：负载型催化剂 金 氧化铝 一氧化碳 氧化 失活 稳定性 

分 类 号：O643.36[理学—物理化学]