Preparation of a hollow b-oriented ZSM-5 zeolite-supported zinc catalyst with enhanced catalytic properties via desilication–recrystallization for methane co-aromatization with propane

Abstract

Hollow b-oriented ZSM-5 with a thickness of approximately 80 nm was synthesized for methane co-aromatization with propane (MCP) through the desilication–recrystallization of b-oriented ZSM-5 using tetrapropylammonium hydroxide (TPAOH) as a template. A hollow structure was introduced into b-oriented ZSM-5 via desilication with OH⁻ and a thin intact shell was formed during recrystallization of leached Si species under TPA⁺ template application. By regulating the recrystallization time, shell thicknesses could be controlled from 120 nm to 60 nm. Under a recrystallization time of 24 h, the hollow b-oriented ZSM-5 possessed suitable acidity as well as the largest S_BET and d_aver. When the hollow b-oriented ZSM-5 zeolite was used as the support for a zinc-based catalyst, aromatic selectivity and the conversion of methane and propane were improved. A maximum aromatic selectivity of 87.5% was achieved, with methane and propane conversion of 10.7% and 77.9%, respectively.