Chemical Fixation of CO2 Into Cyclic Carbonates via Porous Hyper-Crosslinked Polymers Containing Salen(Zn) and Multi-Ionic Sites

The integration of CO 2 capture and conversion into a single heterogeneous catalyst represents a pivotal step toward sustainable carbon resource utilization. Herein, we report a facile synthesis of porous hyper-crosslinked polymers (Salen(Zn)-iHCP) containing salen(Zn) complex and multi-ionic sites via a one-pot Friedel–Crafts alkylation and quaternization strategy. This strategy elegantly overcomes the porosity limitations typically encountered during direct polymerization of charged ionic monomers. The resulting Salen(Zn)-iHCP features a high specific surface area, good CO 2 -selective affinity, and a uniform distribution of proximal Lewis acidic Zn(II) centers and nucleophilic Br − sites. Owing to the synergistic effect between the Zn and Br − sites, coupled with a good CO 2 adsorption capacity, Salen(Zn)-iHCP exhibits high catalytic activity for the cycloaddition of CO 2 with various epoxides in the absence of any additives and solvents. At 100°C and 1.0 MPa, Salen(Zn)-iHCP2 achieves 99% conversion of epichlorohydrin with 97% yield of corresponding cyclic carbonate. Notably, Salen(Zn)-iHCP2 maintains high activity even using simulated flue gas (15% CO 2 in 85% N 2 ) as the carbon source and demonstrates robust recyclability over five cycles. This work provides a promising strategy for constructing high‑performance heterogeneous catalysts for integrated CO 2 capture and conversion.