Platinum-bismuth catalysts for treating engine exhaust
US7611680B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2007 |
| Grant date | Nov 3, 2009 |
| Priority date | — |
| Expiry date | Jan 7, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An engine exhaust catalyst containing precious metal nanoparticles is promoted with bismuth. The bismuth promotion improves the catalyst's CO oxidation performance. Also, by varying the amount of bismuth that is added, the NO conversion rate that can be realized with the catalyst can be controlled. The control over the NO conversion rate is important because the passive regenerative performance of a particulate filter used in engine exhaust systems is based on the amount NO2 that is present in the exhaust stream that reaches the particulate filter. The amount of NO2 being produced needs to be optimized (not necessarily maximized) so that adequate particulate filter regeneration performance can be maintained while avoiding unused, toxic NO2 from being exhausted into the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.