Direct synthesis of hierarchical ZnZSM-5 with addition of CTAB in a seeding method and improved catalytic performance in methanol to aromatics reaction

Abstract

A series of ZnZSM-5 zeolites with hierarchical pores were prepared by a seed-induced method with the addition of cetyltrimethylammonium bromide (CTAB). The influence of the amounts of CTAB on the physicochemical properties of the zeolites was investigated by XRD, FTIR, SEM, TEM, N2 adsorption and desorption, ICP-OES, XPS, NH3-TPD and TG analysis. The results showed that Zn was partially incorporated in the zeolite framework; the addition of CTAB in the synthesis reduced the primary crystal size of the zeolite, but increased the specific surface area and mesopore volume. The catalytic performance of the prepared zeolites was evaluated for methanol to aromatics reaction in a fixed bed reactor. The lifetime of the catalysts was greatly enhanced by the addition of CTAB in the synthesis. The incorporation of Zn increased the selectivity of aromatics.