Maximizing the catalytic performance of FER zeolite in the methanol-to-hydrocarbon process by manipulating the crystal size and constructing a bifunctional system

Although more than 250 different zeolites/zeo-type materials have been discovered to date, the industrial catalyst catalog of the zeolite-catalyzed methanol-to-hydrocarbon (MTH) process is only limited to ZSM-5 (MFI topology with a 10-membered ring (MR)) and SAPO-34 (CHA topology with 8-MR). Herein, the zeolite FER, in principle, could be an attractive alternative as it owns a two-dimensional interconnecting channel system, where a 10-MR channel is perpendicular to the 8-MR channel. However, a shorter lifetime over commercial and literature-reported synthesized FER (avg. 1 hour) is a grave concern. We have strategically integrated material design and catalysis optimization with advanced characterization to improve the catalyst durability of the zeolite FER-catalyzed MTH process. Herein, we report a unique flake-shaped FER (f-FER) zeolite with optimized physicochemical properties that led to a superior lifetime (similar to 3 hours) to commercial FER (similar to 1 hour). Upon combining f-FER zeolite with Y2O3, an unprecedented catalyst lifespan (similar to 20 hours) was accomplished with a preferential selectivity for C4-C7 hydrocarbons. Minimizing the involvement of formaldehyde during the early stages of the MTH process favors the alkene cycle over the arene cycle, eventually extending the catalyst lifetime. An unprecedented catalyst lifespan was accomplished with a preferential selectivity for C4-C7 hydrocarbons by combining Y2O3 with a unique flake-shaped FER zeolite with optimized physicochemical properties.

Automated summary

This study reports a unique flake-shaped FER zeolite with optimized physicochemical properties that offers a potential alternative catalyst for the MTH process. By combining it with Y2O3, a superior catalyst lifespan and selectivity were achieved compared to traditional FER zeolite.