Exhaust emission purifying catalyst device
US7344684B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2004 |
| Grant date | Mar 18, 2008 |
| Priority date | — |
| Expiry date | Apr 13, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
There is provided an exhaust emission purifying catalyst device which is comprised of a carrier disposed in an exhaust passage and including through holes passed through the carrier in an axial direction (flowing direction), and supporting layers made of fire-resistance inorganic oxide formed on inner surfaces of the through holes. The supporting layers support noble metal and NOx trapping agents which occlude NOx in exhaust gas when the exhaust air-fuel ratio is lean, and emits and reduces the occluded NOx when the exhaust air-fuel ratio is stoichiometric or rich. The amount of the supported noble metal is set to be smaller in an exhaust passage upstream area of the carrier than in an exhaust passage downstream area of the carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.