Reduction and re-oxidation of molybdena and vanadia: DFT cluster model studies

Catalytic properties of oxide-based catalysts strongly depend on the mobility and reactivity of surface oxygen as well as on oxide ability to provide oxygen as a reactant and its facility to undergo re-oxidation process. To understand the whole process one of the most important information concerns energetics of creation and annihilation of surface oxygen vacancies. In order to obtain such data theoretical calculations by means of DFT method are carried out. Catalytic activity of different surface species that contain oxygen (surface O centers, surface OH and H2O groups, adsorbed O2) in MoO3 and V2O5 systems are examined using cluster model. In addition, tendency towards an aggregation of surface oxygen vacancies is studied.