Structure of nano-sized CeO2 materials: combined scattering and spectroscopic investigations

DOI: 10.1002/cphc.201600697

Authors: Huw R. Marchbank (University College London (UCL)) , Adam H. Clark (University College London (UCL)) , Timothy I. Hyde (Johnson Matthey Technology Centre) , Helen Y. Playford (ISIS Facility, Rutherford Appleton Laboratory) , Matthew G. Tucker (ISIS; Diamond Light Source; Spallation Neutron Source) , David Thompsett (Johnson Matthey Technology Centre) , Janet M. Fisher (Johnson Matthey Technology Centre) , Karena W. Chapman (Advanced Photon Source) , Kevin A. Beyer (Advanced Photon Source) , Manuel Monte (ESRF-The European Synchrotron) , Alessandro Longo (ESRF-The European Synchrotron; CNR-ISMN) , Gopinathan Sankar (University College London)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Chemphyschem , VOL 17 , PAGES 3494 - 3503

State: Published (Approved)
Published: November 2016

Abstract: The structure of several nano-sized ceria, CeO2, systems was investigated using neutron and X-ray diffraction and X-ray absorption spectroscopy. Whilst both diffraction and total pair distribution functions (PDFs) revealed that in all of the samples the occupancy of both Ce4+ and O2− are very close to the ideal stoichiometry, the analysis using Reverse Monte Carlo technique revealed significant disorder around oxygen atoms in the nano-sized ceria samples in comparison to the highly crystalline NIST standard. In addition, the analysis revealed that the main differences observed in the pair correlations from various X-ray and neutron diffraction techniques were attributable to the particle size of the CeO2 prepared by the reported three methods. Furthermore, detailed analysis of the Ce L3- and K-edge EXAFS data support this finding; in particular the decrease in higher shell coordination numbers with respect to the NIST standard, is attributed to differences in particle size.

Journal Keywords: ceria; EXAFS; pair distribution functions; Reverse Monte Carlo; Rietveld analysis

Subject Areas: Chemistry, Physics, Materials

Facility: BM26A at ESRF; 11-ID-B at Advanced Photon Source

Added On: 02/12/2016 10:44

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Automotive Physics Physical Chemistry Catalysis Chemistry Materials Science Engineering & Technology Nanoscience/Nanotechnology

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