镧、铈比对Pd-TWC性能的协同效应  

The Synergestic Effect of Lanthanium-Cerium Ratio on Catalytic Properties of Pd-TWC

作　　者：金钧[1] 王道[1] 武少华[1] 叶青[1] 周克斌[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100022

出　　处：《北京工业大学学报》2000年第2期68-72,共5页Journal of Beijing University of Technology

基　　金：北京市教委资助!97051200

摘　　要：　研究了以宜兴堇青石蜂窝体为载体，γ－Ａｌ_２Ｏ_３为洗涂层的Ｌａ和Ｃｅ的催化活性与Ｌａ、Ｃｅ物质量的比例关系；探讨了 Ｌａ、 Ｃｅ配比对 Ｐｄ－ＴＷＣ性能的影响．结果表明， Ｐｄ－ＴＷＣ对汽车尾气中 ＣＯ、 ＨＣ、 ＮＯ的催化活性随 Ｌａ、Ｃｅ比的不同而变化，当 ｎ（Ｌａ）∶ ｎ（Ｃｅ）＝ １∶ ４时，催化活性最好，此时，其表面过剩氧量最多； ＸＰＳ分析表明 Ｃｅ以十 ３、＋ ４价共存，且Ｃｅ^（４＋）所占比例在所有样品中最大，为６０％． Ｌａ、Ｃｅ虽为性质相近的稀土元素。The relationship between the activity of La-Ce Catalysts and molar ratio of La-Ce was studied in the paper. These catalysts were prepared by impregnation method using cordierite holeycomb monoliths obtained from Yixing coated by γ-Al_2O_3 as carrier. The effect of the molar ratio of La-Ce on the property of Pd-TWC was also studied. consults showed that the catalytic astivity of Pd-TWC in Purifying CO, HC and NO varied with the ratio of La-Ce. The best catalytic activity was obtained when the ratio was l: 4. Under this circumstances, the amount of resodual oxygen on its surface was largest. XPS results showed that Ce^(4+) coexited with Ce^(3+) and the relative amount of Ce^(4+) is the biggest in all the samples and equaled 60%. La and Ce had a synergestic action on improving catalytic astivity of Pd-TWC.

关 键 词：镧 铈 协同效应 Pd-TWC 催化剂 汽车 尾气净化 

分 类 号：TQ426.96[化学工程] U491.92[交通运输工程—交通运输规划与管理]