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

Abstract 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 (CoO_x@NG) nanocomposites with prominent electron synergistic effect on inner Co─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 CoO_x@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═O bond cleavage for critical *C═O species via ¹³CO₂ isotope and in situ spectroscopy are also demonstrated.