Exhaust gas purifying catalyst
US7998896B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2006 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Aug 25, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purifying catalyst having a good ignition performance is provided. The exhaust gas purifying catalyst 1 includes a catalyst substrate 3 and a catalyst coating layer 5 which contains a noble metal and a refractory inorganic oxide and is formed on the catalyst substrate. The exhaust gas purifying catalyst is characterized in that the catalyst coating layer 5 includes an upstream portion 11 located upstream and a downstream portion 13 located downstream in a flow direction of an exhaust gas. The upstream portion 11 has a layered structure including an upstream portion inside layer 17 and an upstream portion outside layer 15. The upstream portion inside layer contains a cerium-zirconium composite oxide in which a relative proportion of CeO2 is 50 to 95 wt %, as the refractory inorganic oxide, and the upstream portion outside layer 15 and the downstream portion 13 contain a cerium-zirconium composite oxide in which a relative proportion of ZrO2 is 50 to 95 wt %, as the refractory inorganic oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.