Synthesis of highly accessible ZSM-5 coatings on SiC foam support for MTP reaction

摘要

Highly accessible porous ZSM-5 coating with high loading and high adherence was successfully grown on SiC foam support using a two-step coating and steam-assisted crystallization process. The zeolite precursor gel pre-coated on the SiC foam surface and existed in the upper mixed coating layer functioned as a binder to firmly bond the SiC support and the pre-coated zeolite crystals with the formation of a dense ZSM-5 transition layer. The high porosity was achieved from the pre-coated zeolite crystals. The ZSM-5/ SiC foam composite catalyst prepared by the proposed method showed higher propylene selectivity and propylene to ethylene (P/E) ratio, lower C,-C4 saturated hydrocarbons and aromatics and as well as higher stability in comparison to that prepared by conventional in situ hydrothermal process in methanol to propylene reaction.