Process for producing exhaust-gas-purifying catalyst
US5866500A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1995 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | Jul 27, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for producing an exhaust-gas-purifying catalyst includes the steps of immersing a porous support into a solution including a noble metal catalyst ingredient, thereby preparing a support with a noble metal catalyst ingredient loaded thereon, and thermally treating the noble-metal-catalyst-ingredient-loaded support at a temperature of 800.degree. C. or more in non-oxidizing atmosphere. In the thermally-treating step, the noble metal catalyst ingredient is prevented from being oxidized to its oxide, and accordingly it is inhibited from migrating in vapor phase. Further, in the thermally-treating step, pores of the porous support are contracted so that they surround the noble metal catalyst ingredient closely therein. All in all, the noble metal catalyst ingredient is prevented from sintering. Thus, the resulting exhaust-gas-purifying catalyst is of superb heat-resistance, and it can be applied to elevated temperatures of 800.degree. C. or more in fuel-lean atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.