Material with a channel structure for eliminating oxides of nitrogen
US6797247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2002 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Sep 4, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J23/34
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention concerns materials for eliminating oxides of nitrogen NO and NO2 present in exhaust gases, in particular from the internal combustion engines of automotive vehicles operating in a medium that is super-stoichiometric in oxidizing agents, which can adsorb oxides of nitrogen then desorb the oxides of nitrogen by elevating the temperature with respect to the adsorption temperature or by passage of a rich mixture, the materials comprising mixed oxides the metals of which are in octahedral co-ordination, with the octahedra connecting together so that the structure generates micropores in the form of channels. The channel width of the materials is such that the sides are composed of 2 and/or 3 octahedra. These materials adsorb oxides of nitrogen by insertion and do not become poisoned in contact with oxides of sulfur and carbon contained in the gases. In the presence of a group VIII metal or another suitable element such as iron, zinc or aluminum, these materials are capable of eliminating oxides of nitrogen adsorbed by reduction during passage of a rich mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.