钯前驱体对汽车尾气处理Pd/Ce_(0.67)Zr_(0.33)O_2催化剂催化性能的影响(英文)  

The effect of Pd precursor on Pd/Ce_(0.67)Zr_(0.33)O_2 catalysts for automotive emission control

作　　者：林嗣煜 杨林颜 阳雪[1] 周仁贤[1] 

机构地区：[1]浙江大学化学系催化研究所,浙江杭州310028

出　　处：《催化学报》2015年第4期639-648,共10页

基　　金：supported by the National High Technology Research and Development Program of China (863 Program, 2011AA03A406);Zhejiang Leading Team of Science and Technology Innovation (2009R50020)~~

摘　　要：分别以Pd(NO3)2,Pd(NH3)4(NO3)2和H2Pd Cl4为钯前驱体制备了Pd/Ce0.67Zr0.33O2(CZ)催化剂.以硝酸钯为钯前驱体制得的Pd/CZ(NO)催化剂具有较高的储氧量,存在较多的小的钯簇,其钯与载体间相互作用较强,因此在三种新鲜催化剂中对HC和CO的消除表现出了最好的催化活性.以硝酸四氨钯为钯前驱体制得的Pd/CZ(NH)催化剂具有较高的钯分散度,存在较多的大的钯簇,同时存在金属态和氧化态的钯,从而对NO和NO2的消除表现出了较好的催化活性.以氯钯酸为钯前驱体制得的Pd/CZ(Cl)催化剂由于钯分散度较小,钯与载体间作用较弱,存在的CeOCl抑制了氧空穴的生成,因此对各种反应物的催化活性都较低.但Pd/CZ(Cl)催化剂表现出了较好的热稳定性,这是由于老化处理消除了残余的氯物种并且促进了钯与载体间的作用.A Pd/CZ（NO） catalyst prepared with Pd（NO3）2 as the metal precursor exhibited the best catalytic performance for HC and CO elimination because of a higher oxygen storage capacity, abundant small Pdn clusters and a strong Pd-support interaction that facilitated electron transfer from PdO x particles to the CZ support. A Pd/CZ（NH） catalyst prepared with Pd（NH3）4（NO3）2 as the metal pre-cursor exhibited good performance for NO and NO2 elimination due to a higher Pd dispersion, abundant bigger Pdn clusters and oxidized/metallic Pd coexistence. A Pd/CZ（Cl） catalyst prepared with H2 PdCl4 as the metal precursor exhibited low catalytic activity due to a low Pd dispersion, weak Pd-support interaction, and the trace amount of CeO Cl which inhibited oxygen vacancy crea-tion. However, it showed good thermal stability, and benefited when an aging treatment removed the residual chlorine species and also promoted the interaction between PdO x and the support.

关 键 词：钯前驱体 三效催化剂 金属载体间相互作用 起燃催化活性 

分 类 号：O643.36[理学—物理化学] X701[理学—化学]