Ce、Zr双组分改性对Cu/ZSM-5催化剂催化分解NO性能的影响

Effect of Ce and Zr modification on the performance of Cu/ZSM-5 catalysts in direct decomposition of NO

摘要: 采用Ce、Zr双组分对Cu/ZSM-5催化剂进行改性,利用O₂-TPD和TG等手段对催化剂进行表征,考察了离子交换顺序、铈锆摩尔比以及反应条件对催化剂催化分解NO性能的影响。结果表明,铜物种是Zr-Cu-Ce/ZSM-5催化剂中催化分解NO的活性中心,是必须的催化活性组分,Ce、Zr双组分改性能显著提高催化剂在富氧条件下催化分解NO的活性,降低达到最高活性所需要的反应温度。铈锆摩尔比为1:1时,同时进行离子交换制备的Zr-Cu-Ce/ZSM-5催化剂催化分解NO的活性最好。

Abstract: Cu/ZSM-5 catalysts were modified by adding Ce and Zr components and then characterized by O₂-TPD and TG analysis. The effect of ion-exchange sequence, Ce/Zr mol ratio and reaction conditions on the catalytic performance of Ce and Zr modified Cu/ZSM-5 were investigated. The results indicated that Cu species is essential in Zr-Cu-Ce/ZSM-5 catalyst as the active sites for NO decomposition, while the modification with Ce and Zr components can significantly enhance its catalytic performance for direct decomposition of NO in the presence of oxygen and reduce the reaction temperature required for achieving the maximum conversion of NO. The Zr-Cu-Ce/ZSM-5 catalyst modified by simultaneous Ce and Zr ion-exchange with Ce/Zr mol ratio of 1 exhibits thehighest performance for NO decomposition.