Facile synthesis of rodlike ZSM-5 zeolite microspheres and catalytic performance in methanol to propylene reaction

Abstract

Rodlike ZSM-5 zeolite microspheres (R-Z5) were synthesized via a seed induced hydrothermal method with S-1 seeds in the presence of β-cyclodextrin (CD). The synthesized ZSM-5 zeolites were characterized with XRD, SEM, N₂ adsorption and desorption, NH₃-TPD, the catalytic performance of R-Z5 catalysts was studied for the methanol to propylene (MTP) reaction. The effects of the ratio of CD/SiO₂ on the morphologies and textural properties of the products were discussed in detail. A possible formation process of R-Z5 was proposed. The results showed that CD played a key role in the preparation of R-Z5, which could be ascribed to the amphipathy of CD for the formation of rodlike ZSM-5 crystals. Compared with the conventional seed induced method, R-Z5 zeolites possessed the larger BET surface area and mesopore volumes and the more moderate acidic sites. Moreover, the synthesized R-Z5 catalysts exhibited excellent conversion activity (64 h) and propylene selectivity (41.35%) in the primary catalytic performance of MTP reaction.