Particulate matter-oxidizing material and oxidizing catalyst
US7393808B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2004 |
| Grant date | Jul 1, 2008 |
| Priority date | — |
| Expiry date | Jan 17, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/3418
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A particulate matter-oxidizing material which enhances the rate of oxidizing the particulate matter at low temperatures (not higher than about 300° C.), and of which the action for purifying NOx by reduction at high temperatures (not lower than about 500° C.) is not impaired by the oxidizing action. The oxidizing material contains a cerium-zirconium composite oxide for purifying, by burning, the particulate matter in the exhaust gas from a lean-burn internal combustion engine, wherein the cerium-zirconium composite oxide contains cerium in an amount of 0.1 to 20 mol % based on the total mol number of metal atoms that are contained. Desirably, the cerium-zirconium composite oxide further contains at least one kind of metal (M) selected from the rare earth metals (excluding cerium), and the molar ratio of M/Ce is 0.1 to 10.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.