Abstract
Pulsed neutron diffraction measurements on nano-scale powder of ceria, CeO2, uncovered new structural features which appear to be intimately related to the function of this material as an oxygen storage medium in automotive three-way catalytic converters. The results of the pair-distribution function (PDF) analysis and the Rietveld refinement of the neutron diffraction data indicate the presence of interstitial oxygen defects in the octahedral sites of the fluorite structure. The defects were found to disappear following high-temperature treatment. It is suggested that these weakly bound interstitial oxygen defects provide oxygen mobility that facilitates the oxygen storage capacity of ceria in the catalytic converters.
| Original language | English |
|---|---|
| Pages (from-to) | 1345-1356 |
| Number of pages | 12 |
| Journal | Journal of Physics and Chemistry of Solids |
| Volume | 61 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2000 |
| Externally published | Yes |
Funding
The authors are thankful to S. Short for assistance in carrying out experiment, J. Mitchell for technical assistance, and R. Brezny and M. Koranne for providing the sample and for useful discussion. The assistance by W. Dmowski is also acknowledged. The research was supported by the US Department of Energy and the National Science Foundation through the Automotive Initiative Grant DE-FG02-96ER14682.A000. This work has benefited from the use of the Intense Pulsed Neutron Source at Argonne National Laboratory which is funded by the US Department of Energy, BES-Materials Science, under Contract W-31-109-ENG-38.
| Funders | Funder number |
|---|---|
| BES-Materials | W-31-109-ENG-38 |
| US Department of Energy | |
| National Science Foundation | DE-FG02-96ER14682 |
| Argonne National Laboratory |