(651g) Copper Based Catalysts with Balanced Active Sites for Carbon-Oxygen Hydrogenolysis Reactions

Hydrogenolysis of carbon-oxygen (C–O) bonds (e.g., esters, ethers, furfural, and CO₂) has emerged as a versatile synthetic tool in organic methodology, as it could produce a variety of products (e.g., chemicals, fuels, and polymers).1 Copper-based catalysts have been intensively explored for hydrogenation reactions as the copper sites account for the selective hydrogenation of carbon-oxygen bonds and relatively inactive for the hydrogenolysis of carbon-carbon bonds. Despite extensive studies of C-O hydrogenolysis reactions, there is still a debate regarding the nature of active sites of Cu-based catalysts. Work on understanding the active sites of copper catalysts for hydrogenation of dimethyl oxalate (DMO),2 furfural, CO₂ indicted that both Cu⁰ and Cu⁺ species were crucial to the activity of Cu-based catalysts. However, researchers were not able to establish a relationship between activity and Cu⁰/Cu⁺ active species since the strong reductive H₂ and oxidising C=O make the Cu⁰ and Cu⁺ species unstable in the reaction.

We renctly present on efficient approaches for fabrication of a series of nanocatalysts and nanoreactors with stable and balanced Cu⁰ and Cu⁺ active species. We chose the hydrogenation of DMO (a highly exothermic and heat-sensitive system), and hydrogenation of CO₂(the symmetrical molecule with C=O bond) as probe reactions for a better under-standing of properties of active sites and the structure-activity relationship.4 The results indicated a synergy between copper and the oxide components and the balanced surface Cu⁰ and Cu⁺ species can greatly improve the catalytic C-O hydrogenolysis performance of the catalysts.