Chelation and Stabilization of Dynamic Single- Atom Cu in Metal–Organic Frameworks for Selective Hydrogenation Reactions

Selective hydrogenation of unsaturated carbonyl compounds into alcohols is of great importance in the fine chemical industry. Herein, we reported a robust and reusable single-atom Cu catalyst, Cu1@MOF-303, fabricated by a covalent attachment of Cu atoms to the adjacent pair of unsaturated N atoms from two neighboring organic ligands in a metal–organic framework for the selective hydrogenation of aldehydes/ketones, exhibiting high activity with complete conversion and 95% selectivity accompanied by a high product formation rate of 23.6 h–1. A combination of experimental and theoretical studies revealed that the distinctive electronic and structural attributes rendered Cu1@MOF-303 capable of adsorbing targeted functional groups in reactants and desorbing desired products preferentially due to the atomically dispersed Cu species chelated and stabilized by N atoms as well as the dynamic changes by breaking the interfacial Cu–N bonds on reactant adsorption and making these bonds on product desorption, thereby enhancing the catalytic activity and stability.