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 CO 2 hydrogenation to CO. In this study, we report that atomically dispersed Co-doped In 2 O 3 catalysts exhibit improved catalytic performance, methanol selectivity, and reaction stability compared to pristine In 2 O 3 . 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 In 2 O 3, where Co acts as an electron donor to In 2 O 3 . This interaction effectively prevents the excessive reduction of In 2 O 3, stabilizes the surface structure, and ensures long-term reaction stability. Furthermore, isolated Co sites adjacent to oxygen vacancy not only strengthen CO 2 adsorption activation but also facilitate H 2 adsorption dissociation and provide more hydrides to participate in C–H hydrogenations via the formate pathway, thereby achieving high rates of CO 2 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 In 2 O 3 catalysts.