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 CO 2 adsorption on the Ag-loaded Ga 2 O 3 photocatalyst surface is investigated based on VCD analysis. The cluster model constructed by the SSHT approach reasonably reflects the electronic structures of the Ga 2 O 3 surface. The geometry of CO 2 adsorbed on the Ag-loaded Ga 2 O 3 cluster has a bent structure, which is favorable for its photocatalytic reduction to CO.