Method of purifying exhaust gas and catalyst for purifying exhaust gas
US6191061A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1999 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Dec 29, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2255/912
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In an exhaust gas in an oxygen-rich atmosphere, a method of purifying an exhaust gas and a catalyst for purifying an exhaust gas, which can exhibit a high NO.sub.x conversion securely, are provided. Disclosed is a method of purifying an exhaust gas that reduces and purifies NO.sub.x in an exhaust gas in an oxygen-rich atmosphere. Here, as a catalyst for purifying an exhaust gas, a loading layer comprising zeolite is loaded with alumina sulfate and cerium sulfate-zirconium composite oxide, and Pt is loaded on these. And, in a temperature range where HC are not oxidized, the HC are adsorbed and held by the zeolite, the HC, which the zeolite releases at the temperature increment, are subjected to cracking by the zeolite, the alumina sulfate and the cerium sulfate-zirconium composite oxide, and the thus produced low-grade HC are turned into reducing agents, thereby reducing and purifying the NO.sub.x in the exhaust gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.