Synergistic catalysis of cellulose acetate-poly(ionic liquid) composite catalysts toward CO2 cycloaddition reaction

The conversion of CO 2 into cyclic carbonates is crucial for achieving carbon neutrality and enabling resource recycling. Developing efficient heterogeneous catalysts from renewable biomass is a key direction in green catalysis. This study designed a green and efficient heterogeneous catalyst (MCA-PIL) by acetylating bamboo-derived cellulose to construct a porous cellulose acetate support, followed by immobilization of 1-methyl-3-allylimidazolium bromide. The catalyst was systematically characterized using FTIR, XPS, solid-state 13 C NMR etc., which confirmed its chemical structure, hierarchical porosity, and thermal stability. Under optimized conditions (120 ℃, 1.5 MPa CO 2 , 8 h), MCA‑PIL achieved a 99 % yield of chloropropene carbonate from CO 2 and epichlorohydrin without solvent or co-catalyst. The catalyst exhibited broad substrate scope across various epoxides and maintained high activity over five consecutive cycles. Kinetic studies indicated first-order reaction kinetics with an apparent activation energy of 48.35 kJ·mol −1 . Experimental and density functional theory (DFT) analyses revealed a synergistic three-step mechanism: cooperative activation of the epoxide and CO 2 by surface hydroxyl groups and the imidazolium ring, followed by Br - -induced ring-opening, CO 2 insertion, and cyclization to form the product with concurrent catalyst regeneration. This work provides new design principles for biomass‑based catalysts and demonstrates a synergistic strategy integrating CO 2 valorization with renewable material development.