Strong Electronic Interaction between In ₂ O ₃ and Isolated Co Sites Enhancing CO ₂ Hydrogenation to Methanol

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.