采用固态离子交换法制备了不同Cu含量的Cu/ZSM-5改性分子筛型催化剂,并对其理化特性及SCR反应活性进行了表征。结果表明:所制备催化剂中Cu元素富集于分子筛的浅层及表面,并主要以二价铜的形式存在;随Cu含量增加,低温弱酸吸附峰和中温中强酸吸附峰面积增加,有利于提高低温SCR催化性能;铜含量超过13%后,Cu含量的增加对催化剂的低温SCR催化活性影响不大,但将导致高温SCR催化性能急剧恶化;b4催化剂兼具良好的高、低温SCR催化性能,值得深入研究。
Modified Cu/ZSM-5 zeolite catalysts with different Cu contents were prepared by Solid State Ion Exchange(SSIE) method,and were characterized to investigate the physic-chemical properties and performances of SCR.The results show that the doped Cu ions are abundantly dispersed on the surface or superficial zone of the zeolite,and mainly exist in the form of bivalence copper.Absorption area of weak acid sites at low temperature and middle-strong acid sites at middle temperature expand with the increase of Cu content,thus enhances the catalytic performance of SCR at low temperatures.The promotion of increasing Cu loadings on the catalytic performance of SCR at low temperatures becomes unobvious when the Cu contents exceed 13%.but this will result in a drastic decrease of high temperature catalytic performance of SCR.b4 catalyst with good SCR catalytic properties at high and low temperature is worthy for further study.