Metal-free COF–ionic polymer hybrids for efficient CO2 capture and conversion

The industrial implementation of CO 2 cycloaddition remains hindered by catalysts that require multi-step syntheses, co-catalysts or solvents, and yet offer limited recyclability and scalability. Here, we present a metal-free heterogeneous composite catalyst (PImBr@COF) prepared by a 6 h one-pot ship-in-bottle polymerization of imidazolium ionic liquids within the ordered nanochannels of an imine-linked triazine COF (HO-TAPT-COF). This strategy simultaneously embeds Br – nucleophiles, hydrogen-bond donors (-OH) and CO 2 -philic moieties (imine, triazine groups and imidazolium cations) into a crystalline porous scaffold, creating a cooperative activation environment for epoxide ring-opening and CO 2 coupling. The resulting catalyst achieves a CO 2 /N 2 selectivity boost from 14.2 to 24.7, maintains a CO 2 uptake of 50.6 mg g −1 , and delivers a 99.0 % yield of cyclochloroallyl carbonate under solvent- and cocatalyst-free conditions. Remarkably, both CO 2 capture and catalytic activity show negligible decay after ten cycles. Density functional theory calculations reveal that the confined ionic environment significantly lowers the energy barrier for epoxide activation. This work establishes a rapid, scalable and broadly applicable route for constructing multifunctional COF-based catalysts for sustainable CO 2 utilization.