Investigating the Sole Olefin-Based Cycle in Small-Cage Mcm-35 Catalyzed Methanol-to-Olefins Reaction

The small-pore zeolites catalyzed methanol-to-olefins (MTO) reaction proceeds following a dual-cycle (olefin- and aromatic-based cycles) mechanism. Zeolite  topology is a key factor to determining the catalytic route and product selectivity in MTO. Herein, we investigate the mechanistic influence of MCM-35 zeolite on the MTO process. The structural properties of the as-synthesized MCM-35 were carefully characterized and its MTO performances were systematically investigated. When pure methanol was fed to the reactor, almost no MTO process was found although some aromatic species formed inside of zeolite. We assume that the aromatic-based cycle is completely restrained in MCM-35 cages and the olefin-based cycle can’t occur simultaneously. However, cofeeding a little amount of propene in methanol can obviously enhance the methanol conversion under the same reaction conditions. Therefore, we confirmed that the sole olefin-based cycle can still work for the MTO reaction without the accompany of the aromatic-based cycle.