Benzimidazole-based hyper-cross-linked poly(ionic liquid)s for efficient CO2 capture and conversion

Porous materials with high Brunauer-Emmett-Teller (BET) surface area ( S BET ) and abundant ionic active sites facilitate efficient CO 2 capture and conversion. Herein, a kind of novel benzimidazole-based hyper-cross-linked poly(ionic liquid)s (HPILs) were developed via the hyper-cross-linking strategy and the as-prepared HPILs possessed high S BET (485–780 m 2 /g), plentiful micro/mesoporosity, and abundant ionic active sites. The HPILs showed noteworthy CO 2 uptake (79–143 mg/g at 273 K and 1.0 bar), moderate isosteric heats (32–45 kJ/mol), and acceptable CO 2 /N 2 selectivity (IAST: 23–46). Intriguingly, HPILs-Cl-2 exhibited excellent catalytic activity for CO 2 cycloaddition and 99% of propylene oxide was successfully converted to cyclic carbonates under mild conditions (70 °C, 0.1 MPa CO 2 , 9 h). This synthetic strategy is of great importance for the functionalized hyper-cross-linked polymers and the synthesized HPILs are promising for efficient CO 2 capture and conversion under mild conditions.