Oxidation‐State Analysis of Ceria by X‐ray Photoelectron Spectroscopy. Issue 5 (20th February 2015)

• Record Type: Journal Article
• Authors: Allahgholi, Aschkan; Flege, J. Ingo; Thieß, Sebastian; Drube, Wolfgang; Falta, Jens
• Is Part Of: Chemphyschem. Volume 16:Issue 5(2015)
• Page Start: 1083
• Page End: 1091
• Publication Date: 2015-02-20
• Subjects: cerium oxide -- mixed oxides -- photoelectron spectroscopy -- superposition -- thin films; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201402729
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Three different methods to determine the oxide‐phase concentration in mixed cerium oxide by hard X‐ray photoelectron spectroscopy are applied and quantitatively compared. Synchrotron‐based characterization of the O 1s region was used as a benchmark to introduce a method based on the weighted superposition of the Ce 3d spectra of the pure Ce 3+ and Ce 4+ phases, which was shown to lead to reliable and highly accurate determination of the mean oxidation state in mixed cerium oxides. The results obtained reveal a linear relation between the third distinct final state ( u ′′′) satellite peak intensity of the Ce 4+ phase and the Ce 4+ concentration by proper inclusion of Ce 3+ ‐related plasmon satellite peaks, which contradicts previous claims of nonlinear behavior. In contrast, quantitative conventional peak‐fitting procedures were shown to be well suited for the Ce 2p region due to its relatively simple structure. Additional satellite features observed in the Ce 3d spectrum of CeO2 were proposed to originate from plasmon contributions. Abstract : Radiating results: A comprehensive, comparative study of the mixed cerium oxide system targeting quantification of the average oxidation state is presented on the basis of Ce 3d, Ce 2p3/2, and O 1s core‐level photoemission data acquired by using hard X‐ray synchrotron radiation. A superposition method is applied for the Ce 3d core‐level region by using weighted measured spectra representative of the pure Ce 3+ and Ce 4+ phases.