氧化铈对Pd／Al_2O_3表面上CO氧化性能的影响

Effect of CeO2 on Oxidation of CO over Pd/Al_2O3 Catalyst

采用ＴＰＤ－ＭＳ及ＴＰＳＲ－ＭＳ技术研究了添加ＣｅＯ_２对Ｐｄ／Ａｌ_２Ｏ_３催化剂上ＣＯ脱附、表面反应及表面氧脱附等性能的影响，考察了不同含氧量的气氛下ＣＯ的氧化活性．结果表明，Ｐｄ－Ｃｅ间的相互作用有利于各自原子上表面氧的吸脱附及ＣＯ的表面反应，并发现ＣＯ_２脱附量大小及峰温次序与对ＣＯ的催化氧化活性有一致的对应关系．

Surface reaction properties of CO,the desorption properties of surface oxygen over Pd catalysts and their carriers were investigated by means of TPSR-MS and TPD-MS.The oxidation activity of CO on these catalysts was also examined at different concentrations of oxygen. It was found that the desorbed amount of CO2 and the order of peak temperature were in good agreement with their activities.The amount of CO2 in desorbed product on oxidized alumina-supported Pd was more than that on reduced alumina-supported Pd, the disproportionation reaction of CO on H2-reduced Pd/Al2O3 would form carbon and CO2. The results of O2-TPD and CO-TPSR showed that the addition of CeO2 would promote the desorption of surface oxygen and the surface reaction of CO on Pd/Al2O3.