Scaling relations of CO2 hydrogenation and dissociation on single metal atom doped In2O3 catalysts with promoted oxygen vacancy sites†

In this work, we conducted a computational study on single atom doped In₂O₃ catalysts with 12 transition metals (Fe–Cu, Ru–Ag, Os–Au) through density functional theory (DFT) calculations, by investigating the dissociation of H₂, and the dissociation and hydrogenation of CO₂. From the thermodynamic-kinetic scaling relationships such as Brønsted–Evans–Polanyi (BEP) and transition-state scaling (TSS) relations, we establish the descriptors for the energy barriers and improve our understanding of the synergistic catalytic effect of oxygen vacancies and single atoms. We find that the adsorption energy of the H adatom on the perfect surface can serve as an effective descriptor for the dissociation energy barrier of H₂ on this surface, and the formation energy of the oxygen vacancy can serve as an effective descriptor for the energy barrier of CO₂ hydrogenation to HCOO as well as the energy barrier of CO₂ direct dissociation.