Hydrothermally stable catalyst for improved lean NOx reduction
US6936562B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2003 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Nov 10, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Certain metal-exchanged SUZ-4 zeolites have been prepared that have catalytic activity for the reduction of NOx in the exhaust of a hydrocarbon or alcohol fueled engine operated under fuel lean conditions. Initially the SUZ-4 zeolite contains alkali metal cations such as Li+, Na+, K+ and/or Cs+. These alkali metal cation-containing zeolites are partially exchanged with at least one of copper (II), silver (I), iron (III) or cobalt (II) ions. The resulting partially exchanged SUZ-4 zeolites display such activity and are stable under extreme hydrothermal aging conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.