Highly efficient CO₂ capture and chemical fixation of a microporous (3, 36)-connected <i>txt</i>-type Cu(<scp>ii</scp>)-MOF with multifunctional sites

Incorporating multiple functional sites in porous frameworks to enormously enhance the host-guest interactions is an effective strategy to obtain high-performance CO₂ capture and chemical fixation MOF materials. Herein, we designed and constructed a microporous (3, 36)-connected <i>txt</i>-type Cu(II)-based MOF (HNUST-17) from dicopper(II)-paddlewheel clusters and a novel pyridine-based acylamide-linking V-shape diisophthalate ligand with amino groups. Interestingly, with a high density of multiple strong CO₂-philic sites (open metal sites, acylamide and amino functionalities) integrated in the framework, which have been identified by GCMC (Grand canonical Monte Carlo) simulations and DFT (Density functional theory) calculations, HNUST-17 exhibits high and selective capture for CO₂ over CH₄ and N₂ at ambient temperature. Moreover, HNUST-17 possesses efficiently catalytic activity and recyclability for chemical fixation of CO₂ coupling with epoxides into cyclic carbonates in the presence of tetrabutylammonium bromide as the cocatalyst under mild, solvent-free conditions.