Construction of multifunctional histidine-based hypercrosslinked hierarchical porous ionic polymers for efficient CO2 capture and conversion

Several novel multifunctional histidine-based hypercrosslinked ionic polymers (HIPs) were constructed via a one-pot copolymerization strategy. The resultant HIPs were characterized by various technologies and investigated for the CO 2 adsorption and conversion. Plentiful hydrogen bond donors, nucleophilic ionic sites, and Lewis bases were successfully integrated into the HIPs skeletons. As-prepared histidine-based HIPs possess excellent hierarchical pore structure. The optimal HIP-Br-His exhibits a high CO 2 capture capacity of 2.90 mmol/g at 273 K and 1 bar, much higher than that of corresponding hypercrosslinked polymer HCP-Br without histidine units. Meanwhile, the HIP-Br-His achieves an excellent catalytic activity of 95 % product yield with 99 % product selectivity in CO 2 cycloaddition to propylene oxide under metal-, cocatalyst- and solvent-free and mild conditions (70 °C and 1.0 MPa). Particularly, HIP-Br-His can efficiently capture and convert dilute CO 2 into cyclic carbonates with a satisfactory catalytic performance. The excellent catalytic activity associating with the confirmed good stability, recyclability, and substrate compatibility make the developed histidine-based HIPs a promising heterogeneous catalyst for efficient CO 2 capture and conversion.