Supported vanadia (VOx) is a versatile catalyst for various redox processes, where ceria-supported VOx have shown to be particularly active in 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 L3-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/nm2surface 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
Contact
Dr Olga Safonova
SuperXAS beamline
Operando spectroscopy group
Swiss Light Source, Paul Scherrer Intitute
5232 Villigen-PSI, Switzerland
Telephone: +41 56 310 58 05
E-mail: olga.safonova@psi.ch
Original Publication
Activity Trend Origin of Ethanol Oxidative Dehydrogenation over VOx/CeO2
Anna Zabilska, Maxim Zabilskiy, Rob Jeremiah G. Nuguid, Adam H. Clark, Ilia I. Sadykov, Maarten Nachtegaal, Oliver Kröcher, Olga V. Safonova
Angewandte Chemie Int. Ed., 1 March 2023
DOI:10.1002/anie.202301297