Probing redox state dynamics at the surface of MoVTeNbO propane oxidation catalysts by X-ray photo-electron spectroscopy. P. Delichere1, B. Deniau1, T.T. Nguyen1, O. Safonova2, J.M.M. Millet1
Résumé
MoVTe(Sb)NbO catalysts are among the best catalysts proposed for propane oxidation to acrylic acid [1]. The active phase of these catalysts, called M1, is a solid solution containing the four metallic cations. It is generally agreed that in this phase V is the paraffin activator and Te or Sb involved in ą-hydrogen abstraction from the olefin that is formed from the alkane. These elements are strategically placed adjacent to each other in the structure. The oxidation state of both elements at the surface has not been ascertained but it has been shown in the case of Sb that they both participated to the oxido-reduction of the phase [2]. In this presentation we report on the in situ characterization by XPS and XANES of Te containing catalysts upon reduction by propane. The goal was to understand the redox state dynamics at their surface.