Cluster models of the VOx/TiO2 supported catalyst

Molecular structures of the active vanadium phase of the VOx/TiO2 supported catalyst are calculated in the framework of the cluster approximation of density functional theory (DFT). It is shown that vanadium can be stabilized on the anatase (001) surface both in the tetrahedral and octahedral coordinations with the formation of monoxo- and dioxoyanadyl structures. The energy of the dioxoyanadyl structure binding to the support surface is 600-800 kJ/mol. The formation of dioxoyanadyl structures from monoxoyanadyl ones with the formation of water molecules is energetically favorable. The effect of support on the electronic state and acidic properties of the supported vanadium phase is discussed.