Selective CO₂-to-CO Conversion Enabled by Ultrathin Nitrogen-Modified Graphene Confined Cobalt-Cobalt Oxide Nanocomposites with Prominent Electron Synergy

Developing and fabricating cost-effective materials for efficient thermocatalytic reduction of CO2 to CO under mild conditions is a promising and practical way to sustainable and green low-carbon energy systems, which remains a challenge. Herein, a facile high-temperature pyrolysis strategy for the synthesis of efficient ultrathin nitrogen-modified graphene confined cobalt oxide (CoOx@NG) nanocomposites with prominent electron synergistic effect on inner Co & horbar;CoO core and confinement of N-modified graphene shell is reported. The electronic and/or geometric structures of active metallic Co and coordinatively unsaturated CoO species are modulated by the graphene confinement effect. The electron-rich N dopant in the graphene shell enhances the surface electron density of the catalyst, thus regulating the adsorption of acidic CO2 molecules. The engineered CoOx@NG shows an outstanding selective CO2-to-CO efficiency, with a conversion of 19.5% and a near full CO selectivity at 523 K as well as excellent stability for 150 h on stream. Moreover, the in-depth insights into the material microstructure, electron synergy, structure-activity relationships, key intermediate species, and a three-step reaction mechanism involving the rate-determining step of C & boxH;O bond cleavage for critical *C & boxH;O species via (CO2)-C-13 isotope and in situ spectroscopy are also demonstrated.