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

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.