Hydrogen bond donor functionalized poly(ionic liquids)@MIL-101 for the CO2 capture and improving the catalytic CO2 conversion with epoxide

Hydrogen bond donor functionalized poly(ionic liquids) were incorporated into MIL-101 framework for synthesis of composites PIL-R@MIL-101 (R = COOH, OH, NH2). The effect of different hydrogen bond donors on CO2-epoxide cycloaddition reaction was discussed through XPS, NH3-TPD characterizations. Thereinto, PIL-COOH@MIL-101 showed efficient catalytic performance in the cycloaddition reaction of CO2 and epichlorohydrin, 92.7% substrate conversion was obtained under 70 °C, 1.0 MPa, cocatalyst- and solvent-free conditions for 2.5 h. The improved activity was benefited from the synergistic effects of Lewis acidic Cr centers, carboxyl group, and nucleophilic Br-, together with the high surface area (1178 m2/g), and good CO2 affinity. In addition, PIL-COOH@MIL-101 also showed facile recovery method by easy centrifugation and good recycling stability. Considering the good CO2 affinity, excellent catalytic performance in CO2 cycloaddition reaction, better thermal and recycling stabilities, the facilely prepared functionalized poly(ionic liquid)@MIL-101 composite would exhibit promising application prospect in CO2 capture and conversion.