汽车尾气净化非贵金属催化剂SO_2中毒机理研究

STUDIES ON MECHANISM OF SO_2 POISONING OF NON-NOBLE METAL CATALYSTS FOR AUTO-EMISSIOM CONTROL

用TPD,IR,XPS等方法研究了汽车尾气净化的复合氧化物催化剂SO_2中毒机理。结果表明,催化剂SO_2中毒失(?),首先是SO_2在催化剂活性中心上进行化学吸附,然后部分SO_2与活性组分生成相应的亚硫酸盐和硫盐酸,从而使催化剂失活。SO_2的化学吸附及部分生成相应的亚硫酸盐,与生成硫酸盐相比,对催化剂失活的影响,前者更为明显。

Mechanism of SO2 poisoning of non-noble metal catalysts for auto-emission control was studied by TPD, IR,xPS. SO2 was first adsorbed on active sites of catalyst.Then, chemical adsorption of SO2 in part with active components of catalyst had occurred to form sulphite, and sulphate respectively. Thus the catalyst was deactivated.By comparison with the effect of forming sulphate on deactivation of catalyst, the effect of chemical adsorption of SO2 and forming sulphite was more important.