Nitrogen oxide-reducing catalyst and method for reducing nitrogen oxide
US7794680B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 2008 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Apr 28, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02C20/30
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A first catalyst for reducing nitrogen oxides comprising a crystalline silicate containing an iron in β-framework structure wherein a SiO2/Fe2O3 mol ratio is 20-300 and at least 80% of the contained iron is an isolated iron ion Fe3+. A second catalyst for reducing nitrogen oxides comprising a crystalline silicate containing an iron in β-framework structure wherein a SiO2/Fe2O3 mol ratio is 20-300 and log(SiO2/Al2O3) by mol is at least 2. A predominant part of the contained iron is isolated iron ion Fe3+ and at least a part thereof preferably has a tetrahedral coordination. These catalysts have high hydrothermal stability and exhibit enhanced activity for reducing nitrogen oxides by a reaction with a reducing agent such as ammonia, urea or an organic amine in a broad temperature range between lower temperature and higher temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.