Catalytic Conversion of CO2 to Cyclic Carbonates through Multifunctional Zinc-Modified ZSM-5 Zeolite

The production of fine chemicals using CO2 as C-1 building block through inexpensive heterogeneous catalysts with high efficiency under low pressure is challenging. Herein we propose for the first time the utilization of a multifunctional heterogeneous zinc-modified HZSM-5 (ZnHZSM-5) catalyst for upgrading CO2 by incorporation into cyclic carbonates from CO2 and epoxides. Owing to the nice surface properties such as abundant Lewis acid, BrOnsted acid and Lewis base sites, large surface area, and plenty of micropores, CO2 could be concentrated and well activated in ZnHZSM-5 verified by CO2-TPD, TG-MS, etc. Meanwhile, the epoxides were also activated through metal center and hydrogen bond. Therefore, the reaction can easily assemble at the catalyst interface and show exceptional performance, affording the aimed products with high yield of up to 99% in the presence of commercial tetra-n-propylammonium bromide (90% in kilogram scale with 0.004 mol% ZnHZSM-5 and 0.015 mol% (Pr4NBr)-Pr-n).