Exhaust gas purifying catalyst
US8309488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2006 |
| Grant date | Nov 13, 2012 |
| Priority date | — |
| Expiry date | Oct 9, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purifying catalyst includes a catalyst substrate and a catalyst coating layer containing a noble metal and a refractory inorganic oxide. The catalyst coating layer includes an upstream portion located upstream and a downstream portion located downstream in a flow direction of an exhaust gas. The upstream portion has a layered structure including an upstream portion inside layer containing a cerium-zirconium composite oxide in which a relative proportion of CeO2 is 50 to 95 wt %, as the refractory inorganic oxide and an upstream portion outside layer containing a cerium-zirconium composite oxide in which a relative proportion of ZrO2 is 50 to 95 wt %, as the refractory inorganic oxide. The upstream portion outside layer and the downstream portion contain Rh as the noble metal, and an amount of Rh contained in the upstream portion outside layer is larger than an amount of Rh contained in the downstream portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.