Properties of cerium–zirconium mixed oxides partially substituted by neodymium: Comparison with Zr–Ce–Pr–O ternary oxides
| Autor: | François Gérard, J. Mikulova, Sylvie Rossignol, Daniel Duprez, D. Mesnard, Charles Kappenstein |
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| Rok vydání: | 2006 |
| Předmět: |
Zirconium
Praseodymium Coprecipitation Inorganic chemistry chemistry.chemical_element Condensed Matter Physics Oxygen Electronic Optical and Magnetic Materials Inorganic Chemistry symbols.namesake Cerium chemistry Materials Chemistry Ceramics and Composites symbols Physical chemistry Physical and Theoretical Chemistry Ternary operation Raman spectroscopy Sol-gel |
| Zdroj: | Journal of Solid State Chemistry. 179:2511-2520 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2006.04.051 |
| Popis: | CeO{sub 2} doped with praseodymium, neodymium and/or zirconium atoms were prepared by coprecipitation and by the sol-gel method. Structural properties were investigated by in situ XRD and Raman spectroscopy while oxygen storage capacity (OSC) was measured by transient CO oxidation. All the compounds, except pure Nd{sub 2}O{sub 3}, have a fluorite-type structure as well as a Raman band at 560 cm{sup -1} characteristic of the oxygen vacancies involving non-stoichiometric oxides. The lattice parameter under hydrogen, being dependent on the temperature, revealed two reduction mechanisms: one at a low temperature at the surface and another at a high temperature in the bulk. Ce-Nd binary oxides show a strong tendency towards crystallite aggregation, which reduces accessibility to gases and OSC properties. Zirconium improves the thermal resistance to sintering of both Ce-Nd and Ce-Pr oxides. The Zr-Ce-Pr-O followed by Zr-Ce-Nd-O compounds displaying high oxygen mobility at a low temperature, appear to be very promising for practical applications such as OSC materials. - Graphical abstract: Variation of oxygen vacancies under hydrogen on ternary oxides. |
| Databáze: | OpenAIRE |
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