Bifunctional ionic hyper-cross-linked polymers for CO2 capture and catalytic conversion

• This study synthesized a bifunctional ionic hyper-cross-linked polymer. • DHI-CSU-3-Br owns high S BET (1216 m 2 /g) and Br content (0.24 wt%), O content (9.11 wt%). • DHI-CSU-3-Br has good CO 2 capture capacity (134 mg/g, 273 K and 1.0 bar). • These DHI-CSU-Brs had a high CO 2 conversion property under mild conditions (70 ° C 0.1 MPa CO 2 in 4 h). A series of bifunctional ionic hyper-cross-linked polymers were synthesized by the Friedel-Crafts reaction and ionic post-functionalization. The as-prepared polymers had high Brunauer-Emmett-Teller surface areas ( S BET , 623–1345 m 2 /g), considerable bifunctional ionic groups, namely bromide anions, and carboxyl groups. The polymer namely DHI-CSU-3-Br had a good CO 2 capture capacity (134 mg/g, 273 K, and 1.0 bar), moderate isotopic adsorption heat (28–38 kJ/mol), and excellent CO 2 cycloaddition ability. The catalytic experiments showed that 99% of propylene oxide was successfully converted to cyclic carbonate (70 °C, 0.1 MPa CO 2 , and 4 h). The catalytic activity of the polymer was easy to be recovered and it was repeatedly reused 5 times without significant reduction. This synthetic strategy for the preparation of the bifunctional ionic hyper-cross-linked polymers provided an alternative approach for CO 2 capture and catalytic conversion.