Model building of metal oxide surfaces and vibronic coupling density as a reactivity index: Regioselectivity of CO₂ adsorption on Ag-loaded Ga₂O₃

Abstract

The step-by-step hydrogen-terminated (SSHT) model is proposed as a model for the surfaces of metal oxides. Using this model, it is found that the vibronic coupling density (VCD) can be employed as a reactivity index for surface reactions. As an example, the regioselectivity of CO₂ adsorption on the Ag-loaded Ga₂O₃ photocatalyst surface is investigated based on VCD analysis. The cluster model constructed by the SSHT approach reasonably reflects the electronic structures of the Ga₂O₃ surface. The geometry of CO₂ adsorbed on the Ag-loaded Ga₂O₃ cluster has a bent structure, which is favorable for its photocatalytic reduction to CO.