Composite oxide, process for producing the same, and exhaust gas reducing co-catalyst
US7247597B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 2002 |
| Grant date | Jul 24, 2007 |
| Priority date | — |
| Expiry date | Feb 18, 2024 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N2570/16
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A composite oxide includes CeO2, ZrO2 and a metallic oxide being free from reacting with CeO2 and ZrO2 at 700° C. or more, preferably at 900° C. or more and further preferably at 1,000° C. or more. The composite oxide has a regulatory oriented phase, such as a pyrochlore phase, etc., in which at least a part of Ce cations and Zr cations are oriented regularly. The composite oxide makes a catalytic support. The CeO2—ZrO2 composite oxide and the reaction-free metallic oxide make barriers each other which suppress the granular growth when the composite oxide is subjected to high-temperature heat in a reducing heat treatment to form the regulatory oriented phase. The regulatory oriented phase improves the oxygen storage-and-release capability of the catalytic support. Thus, it is possible to simultaneously attain a large a specific surface area and a high oxygen storage-and-release capability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.