Selective Photocatalytic Conversion of CO2 to Formate by Dimeric Cu(II) Complexes

Abstract Efficient and selective molecular catalysts for visible-light-driven CO₂ conversion to liquid or solid fuels are highly desired to achieve carbon neutralization. Although catalysts utilizing earth-abundant metals have shown some progress for CO and formate production, their conversion efficiency and product selectivity are still quite lacking for practical applications. In this study, we report binuclear Cu complexes of bridging ligands containing two pyridyltriazole units developed during the study of the active sites of related metalloenzymes. Surprisingly, the dimeric complexes with a flexible cavity between two coppers exhibit high activity in catalytic CO₂ reduction, converting CO₂ to formate with high selectivity and efficiency under visible light irradiation. The turnover number and formate selectivity were 43000 and >99%, respectively. The results of the study suggest that a deep understanding of the effect of the ligand environment and structural factors of metal compounds on catalytic activity when used as a catalyst will be helpful.