Composite oxide having oxygen absorbing and desorbing capability and method for preparing the same
US5945370A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Dec 5, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2002/88
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A composite oxide having oxygen absorbing and desorbing capability containing 90 to 100 weight % total of cerium, zirconium, and hafnium based on a total amount of metals contained in the composite oxide, the total amount of cerium, zirconium, and hafnium consisting of 14.0 to 70.5 at % cerium, 29.49 to 72.5 at % zirconium, and 0.01 to 13.5 at % hafnium, wherein degree of solid solution of the composite oxide is not lower than 70%, and wherein the composite oxide has reducing property that not less than 90% of tetravalent cerium contained in the composite oxide is reduced into trivalent cerium when the composite oxide is held at 600.degree. C. under a reducing atmosphere; and a method for preparing the composite oxide including the steps of preparing a composite salt from a starting material solution wherein 85 weight % or more of the cerium ions are Ce.sub.4+ by coprecipitation, and subjecting the resulting precipitate to a particular calcining steps including reducing calcination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.