One-pot synthesis of cyclic carbonates from olefins and CO2 catalyzed by silica-supported imidazolium hydrogen carbonate ionic liquids

The direct synthesis of cyclic carbonates by catalytic oxidative carboxylation of olefins with CO2 has become an essential topic, but the development of highly active metal- and halogen-free heterogeneous single catalysts is still a huge challenge. Herein, a series of [Im][HCO3]@SBA-15 supported ionic liquids (SILs) catalysts are prepared by using anion exchange and solvent-free mehcanochemical grafting strategies for the direct synthesis of cyclic carbonates from olefins and CO2. As-prepared [Im][HCO3]@SBA-15 catalysts exhibit excellent catalytic activity and selectivity for the one-pot synthesis of cyclic carbonates from various olefins and CO2 under metal- and halogen-free conditions, providing moderate to excellent yields of cyclic carbonates. Furthermore, the catalysts can be easily regenerated at least five times without significant loss of catalytic activity, exhibiting excellent reusability and stability. This work presents an efficient and green method for the design and preparation of SILs catalysts for CO2 conversion.