Cation Size-Dependent H-ZSM-5 Promotes CO2 Hydrogenation to High-Quality Gasoline

The utilization of metal oxide-zeolite bifunctional catalysts to catalyze the hydrogenation of CO2 into highly value-added products has attracted extensive attention. Due to its acidity and three-dimensional structure, carbon deposition and overcracking generally occur on H-ZSM-5 zeolite, leading to the decline of activity and selectivity. However, the pore structure of zeolite can present a positive effect on the regulation of catalytic behavior. Herein, alkaline solutions (TPAOH/NaOH/TMAH) are used for the H-ZSM-5 enlargehole in order to improve the CO2 hydrogenation performance. The pore size distribution of H-ZSM-5 can be precisely controlled by adjusting the cation size of the alkaline treatment solution. ZSM-5 with a large mesopore size is suitable for the selective conversion of CO2 into high-value gasoline. Thereinto, ZSM-5 maintains its crystal form after being treated with a TPA+ cationic solution, and the stable crystal form ensures the acidity and MFI pore structure. As expected, the large mesopore size enhances the C5–11 selectivity and suppresses the C2–4 selectivity by accelerating the mass transport, avoiding the repeated hydrocracking in the small microporous channel of ZSM-5.