Silver promoted close-coupled NOx absorber
US8920756B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2012 |
| Grant date | Dec 30, 2014 |
| Priority date | — |
| Expiry date | Nov 27, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A50/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Ag/Al2O3 materials may be packaged in a suitable flow-through reactor, in combination with another material selected as a passive NOx adsorber material (PNA), both the silver material and the adsorber material being close coupled to the exhaust manifold of a diesel engine, and upstream of other catalytic devices, such as a diesel oxidation catalyst and a selective reduction catalyst for NOx. The silver catalyst material uses hydrogen in a cold-start engine exhaust and serves to oxidize NO to NO2 in the relatively low temperature, hydrocarbon-containing, exhaust during a short period following the engine cold start, and to temporarily store NOx during the start-up period. After the flowing exhaust gas stream has heated the PNA and the downstream catalytic devices, the silver yields its nitrogen oxides for conversion to nitrogen by the then-operating devices before NOx is discharged to the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.