Strategic design of a bifunctional Ag(i)-grafted NHC-MOF for efficient chemical fixation of CO2 from a dilute gas under ambient conditions

Abstract

The chemical fixation of carbon dioxide into valuable products constitutes a promising step toward reducing the atmospheric CO₂ concentration. Consequently, herein we report the strategic design of a bifunctional catalyst by grafting catalytically active Ag(I) ions onto N-heterocyclic carbene (NHC) sites in a MOF for efficient chemical fixation of CO₂ from a dilute gas to oxazolidinones, bio-relevant commodity chemicals. Indeed, Ag(I)@MOF-NHC demonstrated excellent catalytic activity for efficient fixation of CO₂ from a dilute gas (CO₂ : N₂ = 13 : 87%) with alkynes to afford valuable chemicals, oxazolidinones, under RT and atmospheric pressure (balloon) conditions. The superior activity of the Ag(I) anchored MOF over the individual (AgNO₃ and MOF-NHC) components has been ascribed to the synergistic effect between the CO₂-philic NHC and alkynophilic Ag(I) sites exposed in the 1D channels of the MOF. Furthermore, the Ag(I) anchored MOF showed high recyclability without significant loss of catalytic activity and structural rigidity. Overall, this is a unique demonstration of the utilization of dilute CO₂ under environmentally friendly mild conditions and can pave the way for the development of efficient catalytic systems for sustainable utilization of CO₂ from dilute gases.