Exhaust gas purification catalyst, exhaust gas purification apparatus using the same and exhaust gas purification method
US8337791B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 19, 2009 |
| Grant date | Dec 25, 2012 |
| Priority date | — |
| Expiry date | May 18, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purification catalyst, which is suitable as a three way catalyst for efficiently purifying carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in exhaust gas discharged from a gasoline automobile and exhaust gas purification apparatus using the same and an exhaust gas purification method. <The upper layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-zirconium-type composite oxide (C) containing a pyrochlore phase in a crystal structure, wherein the activated metal (A) is rhodium. <The lower layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-containing oxide (C′) having a cubic crystal and/or tetragonal crystal structure as a major crystal structure, wherein the activated metal (A) is palladium, or palladium and platinum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.