Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-30T20:29:10.534Z Has data issue: false hasContentIssue false
  • English
  • Français

Structural Defects In Cerium Oxide Catalytic Support Studied by Pulsed Neutron Diffraction

Published online by Cambridge University Press:  15 February 2011

E. Mamontov ,
T. Egami  and
R. Brezny
E. Mamontov
Affiliation:
MSE Department, University of Pennsylvania, Philadelphia, PA 19104, mamontov@soll.lrsm.upenn.edu
T. Egami
Affiliation:
MSE Department, University of Pennsylvania, Philadelphia, PA 19104, mamontov@soll.lrsm.upenn.edu
R. Brezny
Affiliation:
Grace Davison, Columbia, MD 21044
Get access

Abstract

We studied the structure of coarse and nano-scale powders of CeO2 using pulsed neutron scattering. The diffraction data were analyzed using Rietveld refinement, and were also Fourier-transformed to obtain the pair-distribution function (PDF). The Frenkel type oxygen defects consisting of vacancies in the oxygen sublattice and oxygen ions in the octahedral interstitial sites of the fluorite structure were observed in cerium oxide for the first time. The interstitial oxygen ions were found to recombine with vacancies when the sample underwent thermal treatment at 1073 K. We suggest that these defects are directly involved in the oxygen storage mechanism of ceria used in automotive catalytic converters.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 549: Symposium FF – Advanced Catalytic Materials - 1998 , 1998 , 185
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Dmowski, W., Toby, B.H., Egami, T., Subramanian, M.A., Gopalakrishnan, J., and Sleight, A.W., Phys. Rev. Lett. 61, 2608 (1988).Google Scholar
2. Egami, T. and Billinge, S.J.L, Prog. Mater. Res. 38, 359 (1994).Google Scholar
3. Rosenfeld, H.D. and Egami, T., Ferroelectrics 150, 183 (1993).Google Scholar
4. Egami, T., J. Phys. Chem. Solids 56, 1407 (1995).Google Scholar
5. Warren, B.E., X-ray Diffraction (Dover Publications, New York, 1990), p. 120.Google Scholar
6. Von Dreele, R.B., Jorgensen, J.D., and Windsor, C.G., J. Appl. Cryst. 15, 581 (1982).Google Scholar
7. Toby, B.H. and Egami, T., Acta Cryst. A 48, 336 (1992).Google Scholar
8. Press, W.H., Teukolsky, S.A., Vetterling, W.T., and Flannery, B.P., Numerical Recipes in FORTRAN: The Art of Scientific Computing, 2nd ed. (Cambridge University Press, New York, 1992), p. 436.Google Scholar
9. Cheetham, A.K., Fender, B.E.F., and Cooper, M.J., J. Phys. C: Solid St. Phys. 4, 3107 (1971).Google Scholar
10. West, A.R., Solid State Chemistry and its Applications (John Wiley & Sons, UK, 1995), p. 331.Google Scholar