Targeted Weaving of Triazine Ionic Polymers Within the Pores of Covalent Organic Frameworks for Enhanced CO2 Conversion.

The chemical conversion of carbon dioxide (CO2) is crucial for mitigating global warming and creating economic value. A particularly promising approach is the cycloaddition of CO2 with epoxides to produce cyclic carbonates. Nevertheless, designing green and highly efficient heterogeneous catalysts remains a key challenge in this process. Based on a function-oriented molecular design strategy, this study developed a series of composite materials, COF-TIPs-X (X = 1, 2, 3, or 4), by precisely controlling the grafting density of triazine ionic polymers (TIPs) onto the framework of covalent organic frameworks (COFs). The resulting hybrid materials exhibit significantly enhanced CO2 catalytic performance compared to the pristine COFs, which is attributed to their porous structures enriched with accessible ionic and basic nitrogen sites. Under metal-free, solvent-free, and cocatalyst-free conditions, these materials efficiently catalyze the conversion of CO2 into various cyclic carbonates, achieving yields of up to 99%. Importantly, the chemical grafting approach imparts remarkable stability to COF-TIPs-3, as evidenced by its sustained catalytic activity over five consecutive cycles. This study provides valuable insights into the development of ionic-COFs materials for efficient CO2 conversion.