Catalytic Properties of Ionic Covalent Organic Frameworks (COFs) Materials in CO2 Cycloaddition

• • EB-BT(OH) achieves 99% product yield at 120 °C and 2.0 MPa CO2 without co-catalysts, demonstrating industrially relevant performance for cyclic carbonate synthesis. • • The ionic COF integrates acid (hydroxyl), base (nitrogen), and nucleophilic (Br−) sites in a single framework, enabling synergistic catalysis and eliminating the need for additional co-catalysts, reducing process complexity and cost. • • Systematic tuning of hydroxyl content in the COF skeleton reveals a direct correlation between hydrogen bond donor density and catalytic activity, providing quantitative design guidelines for optimizing CCE catalysts. • • The catalyst operates under mild conditions (120 °C, 2.0 MPa) compared to traditional processes, potentially lowering energy consumption and improving process safety for industrial CO2 fixation.