Surface dealumination of micro-sized ZSM-5 for improving propylene selectivity and catalyst lifetime in methanol to propylene (MTP) reaction

摘要

Novel micro-sized ZSM-5 zeolite was successfully prepared by a two-stage glucose-assisted crystallization and a selective surface dealumination process before removing the templates for methanol to propylene (MTP) reaction. The structural and crystalline properties of the as-prepared ZSM-5 were characterized by XRD, XPS, SEM, MR, and NMR analyses. Results showed that novel ZSM-5 zeolites with micro-sized crystals had better performances in improving the propylene selectivity in the MTP reaction than those conventional ZSM-5 zeolites with nano-sized crystals. The surface dealumination before the template removal obviously decreased the concentrations of surface aluminum atoms and significantly improved lifetime of catalysts in MTP reaction.