Catalyst for cleaning exhaust gas
US6090744A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1997 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Mar 27, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In the exhaust gas purifying catalyst (3), palladium is contained as a catalytic component and cerium oxide and (Ce, Pr) compound oxide is contained as a promoter. Now, the weight ratio of cerium oxide to (Ce, Pr) compound oxide is set between 9/1 and 7/3, and the ratio of praseodymium to cerium in the (Ce, Pr) compound oxide is set between 3 mol % and 50 mol %. In this way, because in this exhaust gas purifying catalyst (3), palladium with high low-temperature activity is used for a catalytic component, the exhaust gas purifying performance at low temperature is improved. And because cerium oxide and (Ce, Pr) compound oxide improves catalytic activity of palladium at high temperature, the exhaust gas purifying performance at high temperature, in particular, NOx purifying performance, is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.