Zabilska, AnnaZabilskiy, MaximNuguid, Rob Jeremiah G.Clark, Adam H. H.Sadykov, Ilia I. I.Nachtegaal, MaartenKroecher, OliverSafonova, Olga V. V.2023-04-242023-04-242023-04-242023-03-2310.1002/anie.202301297https://infoscience.epfl.ch/handle/20.500.14299/197078WOS:000955428900001Supported vanadia (VOx) is a versatile catalyst for various redox processes where ceria-supported VOx have shown to be particularly active in the oxidative dehydrogenation (ODH) of alcohols. In this work, we clarify the origin of the volcano-shaped ethanol ODH activity trend for VOx/CeOx catalysts using operando quick V K- and Ce L-3- edge XAS experiments performed under transient conditions. We quantitatively demonstrate that both vanadium and cerium are synergistically involved in alcohol ODH. The concentration of reversible Ce4+/Ce3+ species was identified as the main descriptor of the alcohol ODH activity. The activity drop in the volcano plot, observed at above ca. 3 V nm(-2) surface loading (ca. 30 % of VOx monolayer coverage), is related to the formation of spectator V4+ and Ce3+ species, which were identified here for the first time. These results might prove to be helpful for the rational optimization of VOx/CeO2 catalysts and the refinement of the theoretical models.Chemistry, MultidisciplinaryChemistryheterogeneous catalysisoxidative dehydrogenationreaction mechanismssupported catalystsx-ray absorption spectroscopyvanadium-oxide catalystsmethanol oxidationceriareactivityclusterstext::journal::journal article::research article