Exhaust gas purification apparatus for an internal combustion engine
US5313792A · kind A · utility
32Cited by
6References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1992 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Sep 18, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purification system includes a transition metal/zeolite first catalyst, a three-way second catalyst, and a noble metal-type third catalyst arranged in that order in the direction of exhaust gas flow in an exhaust conduit of an internal combustion engine capable of fuel combustion at lean air-fuel ratios. NOx which has not been purified by the transition metal/zeolite first catalyst is oxidized by the three-way second catalyst into NO.sub.2, which the noble metal-type third catalyst can easily decompose into N.sub.2 and O.sub.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.