Strong ElectronicInteraction between In₂O₃ and Isolated Co SitesEnhancing CO₂ Hydrogenationto Methanol

Abstract

Co single-atom catalysts have been demonstrated to be promising in advanced oxidation processes and CO₂ hydrogenation to CO. In this study, we report that atomically dispersed Co-doped In₂O₃ catalysts exhibit improved catalytic performance, methanol selectivity, and reaction stability compared to pristine In₂O₃. Experimental results confirm that the isolated Co sites are extremely stable and difficult to aggregate in reducing environments, attributed to a strong electronic interaction between Co and In₂O₃, where Co acts as an electron donor to In₂O₃. This interaction effectively prevents the excessive reduction of In₂O₃, stabilizes the surface structure, and ensures long-term reaction stability. Furthermore, isolated Co sites adjacent to oxygen vacancy not only strengthen CO₂ adsorption activation but also facilitate H₂ adsorption dissociation and provide more hydrides to participate in C–H hydrogenations via the formate pathway, thereby achieving high rates of CO₂ conversion and methanol formation. This work elucidates the properties of the active structure at the atomic level, providing a fundamental understanding of the structure–performance relationship over atomically dispersed Co-doped In₂O₃ catalysts.