Lean NO.sub.x catalyst/trap method
US5874057A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1995 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Jul 12, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N2570/16
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A NO.sub.x abatement composition comprises a NO.sub.x abatement catalyst and a NO.sub.x sorbent material which are dispersed in proximity to, but segregated from, each other on a common refractory carrier member (10). The NO.sub.x sorbent material comprises a basic oxygenated metal compound and optionally further comprises ceria. The NO.sub.x abatement catalyst contains a catalytic metal component including a platinum metal catalytic component. The catalytic metal component is segregated from the NO.sub.x sorbent material, which may be one or more of metal oxides, metal carbonates, metal hydroxides and mixed metal oxides. At least the catalytic metal component and the NO.sub.x sorbent material must be on, or comprise separate, particles; the particles may either be admixed or may be disposed in separate layers (20a, 20b) on the carrier member (10). A NO.sub.x abatement method employs the composition and includes periodically adjusting the gas being treated between lean and stoichiometric/rich operating cycles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.