Efficient CO2 fixation under atmospheric pressure using a metal- and halide-free heterogeneous catalyst†

Abstract

The quest for developing heterogeneous catalysts to synthesize cyclic carbonates from epoxides and carbon dioxide (CO₂) has attracted the attention of scientists in the past decade. Particularly, it is challenging to prepare cyclic carbonates using CO₂ under atmospheric pressure without the use of metal ions, additives, solvents, and halide ion-containing cocatalysts. This work reports the development of a metal- and halide-free porous organic polymer (POP) catalyst for the CO₂ fixation reaction. The POP synthesised from terephthaldehyde and 2,4,6-triaminopyrimidine possesses various functional groups (–NH₂, –NH, pyridine-N, etc.) that are known to activate epoxides and CO₂. The as-prepared POP displays excellent catalytic activity in the conversion of different epoxides to their corresponding cyclic carbonates with significant quantitative yields and selectivity. Additionally, the catalyst displays good recyclability without any noteworthy loss of catalytic activity and structural integrity, signifying its heterogeneous nature.