Imidazolium- and Triazine-Based Ionic Polymers As Recyclable Catalysts for Efficient Fixation of CO2 into Cyclic Carbonates

In this work, a series of imidazolium- and triazine-based ionic polymers were synthesized by solvothermal and ball-milling methods. The structures of these IPs were characterized by FTIR, XPS, SEM, XRD, TGA, and the catalytic activity of IPs was evaluated for the cycloaddition reaction of CO2 and epoxides under solvent- and additive-free conditions. These IPs synthesized by solvothermal or ball-milling methods show satisfactory catalytic activity, giving the yield of cyclic carbonates up to 99 %. Furthermore, the IPs catalyst could be easily reused and there was not significant decrease in catalytic activity. In addition, a plausible catalytic mechanism was also proposed. As a result, the ball-milling synthesis of ionic polymers for CO2 conversion is expected to replace traditional solvothermal synthesis due to the straightforward and green synthesis route.