In‐situ Synthesis of Ionic Liquids on B‐doped Mesoporous SiO2 Catalyst for Epoxide‐CO2 Cycloaddition

Abstract A series of functionalized ionic liquids (ILs) immobilized on B‐doped mesoporous SiO 2 catalysts were fabricated for effectively converting CO 2 into cyclic carbonates under metal‐absent and cocatalyst‐free conditions. Functionalized imidazolium ILs were in‐situ synthesized by Debus‐Rdziszewski imidazole reaction. Among the prepared catalysts, 5B−SiO 2 −NH 2 −3−I catalyst owing to the synergistic effects of nucleophile, Lewis acid‐base and hydroxyl hydrogen bond donors in the catalyst, presented the better catalytic activity for propylene epoxide to the product of propylene carbonate with 99% yield and selectivity at 110 °C and 2 MPa CO 2 . The catalyst also displayed moderate yield for various mono‐substituent epoxides. Besides, the gradual decline in the product yield during consecutive runs could be easily refreshed by aqueous acidic solution washing.