Surface chemistry of phase-pure M1 MoVTeNb oxide during operation in selective oxidation of propane to acrylic acid

► The surface of MoVTeNb oxide is characterized by a high number of energetically equivalent sites for propane adsorption. ► Restructuring of the catalyst surface during propane oxidation has been monitored under working conditions. ► Acrylic acid formation correlates with surface depletion in Mo6+ and enrichment in V5+ sites. ► The active ensemble contains V5+ oxo-species in close vicinity to Te4+ sites.