摘要
采用共沉淀法制得了Ｃｅ４＋部分取代Ｌａ３＋的Ｌａ１－ｘＣｅｘＭｎＯ３钙钛矿型催化剂。实验结果表明，随Ｃｅ４＋取代量ｘ的增大，Ｌａ１－ｘＣｅｘＭｎＯ３催化剂越易被还原，其还原活化能逐渐降低。对于ＣＯ、ＣＨ４氧化反应其活性有一最大值，ＣＯ反应ｘ为０．４，ＣＨ４反应ｘ为０．２。这是由于随ｘ值的增大，催化剂晶格缺陷增多，晶格氧的化学势增大，以及ＣｅＯ２杂质相的协同作用的结果。在ＣＯ氧化和用Ｈ２还原中，发现两种氧种在反应中起作用，即低温时为吸附氧。
TheLa 1-x Ce xMnO 3 perovskite-type catalysts prepared by copreipitation.The Catalytic properties of the perovskite-type catalysts La-Ce-Mn system have been studied by means of XRD,TPR,activity evaluation etc..The results of the tests reveal that the reduction activitionenergy of La 1-x Ce xMnO 3 catalysts decrease with increase of xfrom 0.0 to 0.6 and activity of the cataysts for CO and CH 4 oxidation have a maxium point (for CO oxidation x=0.4 and for CH 4 oxidation x=0.2). It is considered that the above behaviour is caused by the enhancement of lattice defect and the chemical potential of lattic oxygen in the catalysts with the increase of x.
基金
国家自然科学基金
关键词
钙钛矿型催化剂
催化性能
汽车尾气
净化
Perovskite-type catalysts Catalytic oxidation of CO and CH 4 Catalytic performancee
