1999/01/01 by E. Fonda, Emiliano Fonda, D. Andreatta +3 · 2 citations
Materials Science · Physics and Astronomy · #Catalytic Processes in Materials Science #Electron and X-Ray Spectroscopy Techniques #X-ray Spectroscopy and Fluorescence Analysis
paper · pdf · doi:10.1107/s0909049598010280
openalex publication_date 1999/01/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Cerium oxide (IV) (CeO2) is extensively employed in heterogeneous catalysis, particularly as a promoter of noble metal action in three-way catalysts. For this reason there is a great scientific and economical interest in the development of any possible chemical or structural analysis technique that could provide information on these systems. EXAFS spectroscopy has revealed itself as a powerful technique for structural characterization of such catalysts. Unfortunately, good quality K-edge spectra of cerium are not yet easily obtainable because of the high photon energy required (>40 keV). On the other hand, at lower energies it is easy to collect very good spectra of the L3 edge (5.5 keV), but L3-edge spectra of cerium (IV) are characterized by the presence of two undesired additional phenomena that interfere with EXAFS analysis: final-state mixed-valence behaviour and intense multi-electron excitations. Here, a comparative analysis of the K, L3, L2 and L1 edges of Ce in CeO2 has been made and a procedure for obtaining structural parameters from L3-edge EXAFS, even in the presence of these features, has been developed. This procedure could allow further studies of catalytic compounds containing tetravalent cerium surrounded by oxygen ligands.