Influence of Cu on the catalytic activity of FeBEA zeolites in SCR of NO with NH3

Abstract

Two series of Fe and/or Cu containing BEA zeolites were prepared by different procedures: two-step postsynthesis method (FexSiBEA, CuxSiBEA and FexCuxSiBEA) and conventional wet impregnation (FexHAlBEA, CuxHAlBEA and FexCuxHAlBEA) (x=1.0 Fe or Cu wt%). Modification of BEA zeolite resulted in the incorporation of iron and/or copper into vacant T-atom sites of the zeolite framework as evidenced by XRD and DR UV–vis. Transition metals (Cu or Fe) were incorporated into the framework of BEA zeolite as pseudo-tetrahedral Fe (III) or Cu (II) as proved by XRD, DR UV–vis and TPR investigations. All of obtained zeolite materials were found to be active catalysts of selective catalytic reduction of NO with ammonia. Analysis of NO conversion and catalyst reducibility indicated that the latter played an important role in the DeNOx process. Co-presence of copper in the zeolite structure decreased the reducibility of iron in FexCuxSiBEA and FexCuxHAlBEA, and had significant influence on the low temperature NO conversion.