Method of purifying exhaust gas from internal combustion engine
US5997830A · kind A · utility
19Cited by
5References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 13, 1997 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Jun 13, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This method comprises bringing exhaust gas from an internal combustion engine, which is operated at a fuel-lean air/fuel ratio, in contact with an iridium-containing catalyst in a first zone and then in contact with a platinum-containing catalyst in a second zone situated downstream of the first zone. This method is effective for exhaust gas from lean burn engines over a wide temperature range of 200 to 500.degree. C., produces less N.sub.2 O in a low-temperature range of 200 to 300.degree. C., and can purify exhaust gas stably and effectively even at a high temperature of 700.degree. C. or over.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.