Catalyst for purifying oxygen rich exhaust gas
US5990038A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Feb 23, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention relates to a first catalyst for purifying an exhaust gas. The first catalyst has a substrate and a catalytic coating formed thereon. This catalytic coating has first and second grains. The first grain includes a porous carrier supporting thereon at least one of palladium and rhodium. The second grain includes a double oxide supporting thereon at least one of platinum and palladium. This double oxide is represented by a formula of (La.sub.1-x A.sub.x).sub.1-.alpha. BO.sub..delta. where A is at least one element selected from barium, potassium and cesium, B is at least one of iron, cobalt, nickel and manganese, 0<X<1, 0<.alpha.<0.2, and .delta. is a number such that a net electric charge of the first double oxide becomes zero. The invention further relates to a second catalyst similar to the first catalyst. The first grain of the second catalyst includes a porous carrier supporting thereon at least one of platinum, palladium, rhodium and iridium. The second grain of the second catalyst includes a double oxide represented by a formula of (La.sub.1-x A.sub.x).sub.1-.alpha. BZr.sub..beta. O.sub..delta. where A, B, x, .alpha. and .delta. are defined as above and 0<.beta.<1.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.