Exhaust gas purifying catalyst
AssigneeCataler Corporation
InventorsTakashi Goto, Kenichi Taki, Satoshi Matsueda
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Abstract
The exhaust gas purifying catalyst presented here includes a substrate and a catalyst coat layer formed on the surface of the substrate. The catalyst coat layer is formed in a laminate structure having two layers, with a first layer being nearer to the surface of the substrate and a second layer being relatively further from this surface. The second layer includes a carrier and a noble metal supported on the carrier. The first layer is a noble metal-free layer that does not contain a noble metal but does contain an OSC material having oxygen storage capacity.
Claims6
An exhaust gas purifying catalyst which is disposed in an exhaust passage of an internal combustion engine and eliminates NOx contained in exhaust gas,
- the exhaust gas purifying catalyst comprising:
- a substrate;
- and a catalyst coat layer formed on a surface of the substrate, wherein
- the catalyst coat layer consists of a first layer formed on the surface of the substrate and a second layer formed on the surface of the first layer,
- the second layer includes a carrier and a noble metal supported on the carrier, and
- the first layer is a noble metal-free layer that does not contain a noble metal but does contain an OSC material having oxygen storage capacity,
- wherein the second layer comprises Rh and Pt, and
- the mass ratio of Rh and Pt (Rh/Pt) contained in the second layer is between 1/1 and 4/1.
Dependencies are inferred from the claim text.