汽车尾气净化用钯催化剂的制备及活性考察  

Preparation of Automotive Palladium-only Catalyst and Its Three-way Catalytic Behaviour

作　　者：高平[1] 崔芳[1] 何春燕[1] 彭港发[1] 王历虎[1] 白庭芳[1] 

机构地区：[1]中国科学院兰州化学物理研究所精细石油化工中间体国家工程研究中心,甘肃兰州730000

出　　处：《分子催化》2004年第3期203-207,共5页Journal of Molecular Catalysis(China)

摘　　要：制备了一系列用于净化汽车尾气的新型钯催化剂.该催化剂以堇青石蜂窝陶瓷为基体与含助剂的γ-Al2O3涂覆层构成载体,La、Ce、Pr、Sm、Nd、Eu、Mg、Ca、Ba、Sr、Ni、Fe、Mn等的复合氧化物为助催化剂,主活性组分钯,含量为0.05%.在实验室配气条件下,对该系列催化剂进行三效活性的测试,结果显示催化剂对CO.THC.NO的T50分别为188℃,213℃,204℃,经空气中1000℃/4h的快速热老化后(相当于汽车运行5万公里),T50分别为202℃,231℃,222℃;表明,部分助剂引入涂层,增大了载体的比表面积,提高了载体的抗热冲击能力;以氧化物形式引入的另一部分助剂同时起到分散和稳定贵金属的作用,且钯与其产生协同作用,对改善钯催化剂的三效性能有显著效果.A series of Pd-only catalyst were prepared. In the catalysts, a ceramic honeycombs cordierite, the γ-Al_2O_3 and Palladium (0.05% wt.) were adopted as carrier medium, washcoat material and the main active components respectively; Si, La, Ce, Pr, Sm, Nd, Eu, Mg, Ca, Sr, and Ba were used as the stabilizers, and were doped by other assistant chemical elements (Ni, Fe and Mn). The catalytic activity of the catalysts were tested in a lab-scale plug flow reactor (PFR). The light-off temperatures, at which a 50% conversion was obtained on the fresh and aged catalyst, were CO, 188 ℃、 202 ℃, THC, 213 ℃、 231 ℃, NO, 204 ℃、 222 ℃, respectively. The experimental results have demonstrated that the catalysts have low light-off temperature, good catalytic activity and thermal durability. Conclusions are drawn on the effects of non-noble oxides on the catalytic activity. The results showd that the high activities and low light-off temperatures of the catalysts were depend on the strong interaction among the active components.

关 键 词：汽车尾气净化 钯催化剂 制备 催化活性 三效催化剂 整体式催化剂 

分 类 号：X734.201[环境科学与工程—环境工程] O643.36[理学—物理化学]