Selective catalytic reduction type catalyst
US7906449B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 2008 |
| Grant date | Mar 15, 2011 |
| Priority date | — |
| Expiry date | May 5, 2028 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J29/7615
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention is a selective catalytic reduction type catalyst for purifying nitrogen oxides in exhaust gas exhausted from lean combustion engines using ammonia or urea as a reducing agent, it is provided with a selective catalytic reduction type catalyst The catalyst comprises a lower-layer catalyst layer (A) having an oxidative function for nitrogen monoxide (NO) in exhaust gas and an upper-layer catalyst layer (B) having an adsorbing function for ammonia on the surface of a monolithic structure type carrier (C), and that the lower-layer catalyst layer (A) comprises a noble metal component (i), an inorganic base material constituent (ii) and zeolite (iii), and the upper-layer catalyst layer (B) comprises substantially none of component (i) but the component (iii).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.