The Journal of Physical Chemistry C · 2007 · 34 citations · 32 references
Natural SciencesChemistryMaterials ScienceCatalysisInorganic ChemistrySurface ScienceCatalyst CharacterizationMetal OxidesSurface OxidationSurface ReactivityThin Film OxidationX-ray Photoelectron SpectroscopyOxidation MechanismsOxidation State ChangesOxidation State DependenceOxidation StatesSolution StoichiometrySurface Oxidation MechanismsSurface Oxidation StatesThin Oxide Films
X-ray photoelectron spectroscopy (XPS) has been used to investigate the stoichiometry of CeO 2- x (111) ultrathin films grown on Rh(111), as well as the modification of the average Ce oxidation state by Pd and CO at room temperature. The stoichiometry of three-layer CeO 2- x (111) has been varied between CeO 1.91 and CeO 1.61 by altering the oxygen pressure during Ce deposition. Pd deposition induces a change in the Ce oxidation state that is highly dependent on the initial stoichiometry of the CeO 2- x films. The difference in behavior of CeO 2- x thin films with different oxidation states is ascribed to the presence of a Ce 2 O 3 (0001) termination of the more reduced thin films. CO adsorbs only in the presence of Pd, independent of the stoichiometry of the original film, without changing the oxidation state of the CeO 2- x thin film.
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XPS Study of the reduction of cerium dioxide
Michelangelo Romeo, Klaudia Bąk, Jaâfar El Fallah et al. · Surface and Interface Analysis · 1993 · 660 citations