US5019546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for purifying exhaust gas and method of manufacturing the same
Assignee: Mazda Motor Corp
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Filing: 1990-02-05
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Granted: 1991-05-28
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Expires: 2010-02-05
Abstract
Abstract A catalyst for purifying exhaust gas, comprising a catalyst carrier, a first coating layer formed on a surface of the catalyst carrier and mainly consisting of active alumina oxide containing platinum and rhodium and a second coating layer formed on a surface of the first coating layer and mainly consisting of palladium and composite powder including zirconium oxide and lanthanum oxide fixed on a surface of cerium oxide, and a method of manufacturing the catalyst.
Inventors
- 👤 Hiroshi Murakami
- 👤 Masayuki Koishi
- 👤 Shoko Yatagai
- 👤 Kazuko Yamagata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:04
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/63; B01J37/00; B01J37/02; B01J37/024; F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N2510/00; F01N2510/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
72 words
A catalyst for purifying exhaust gas, comprising: a catalyst carrier; a first coating layer which is formed on a surface of said catalyst carrier and mainly consists of active alumina containing platinum and rhodium; and a second coating layer which is formed on a surface of said first coating layer and mainly consists of palladium and a composite powder including oxides of zirconium and lanthanum fixed on a surface of cerium oxide.
Claim 2
Dependent Claim
72 words
A catalyst for purifying exhaust gas, comprising: a catalyst carrier; a first coating layer which is formed on a surface of said catalyst carrier and mainly consists of active alumina containing platinum and rhodium; and a second coating layer which is formed on a surface of said first coating layer and mainly consists of palladium and a composite powder including oxides of zirconium and lanthanum fixed on a surface of cerium oxide.
Claim 3
Dependent Claim
17 words
A catalyst as claimed in claim 1, wherein said catalyst carrier is formed in a honeycomb structure.
Claim 4
Dependent Claim
20 words
A catalyst as claimed in claim 1, wherein said second coating layer contains 1 to 10 wt. % of zirconium.
Claim 5
Dependent Claim
20 words
A catalyst as claimed in claim 1, wherein said second coating layer contains 1 to 10 wt. % of lanthanum.
Claim 6
Dependent Claim
20 words
A catalyst as claimed in claim 1, wherein said second coating layer contains 5 to 30 wt. % of cerium.
Claim 7
Dependent Claim
28 words
A catalyst as claimed in claim 5, wherein said second coating layer contains 1 to 10 wt. % of zirconium and 1 to 10 wt. % of lanthanum.
Claim 8
Dependent Claim
25 words
A catalyst as claimed in claim 6, wherein said first coating layer contains not less than a total of 1.0 g/l of platinum and rhodium.
Claim 9
Dependent Claim
20 words
A catalyst as claimed in claim 6, wherein said second coating layer contains not less than 0.5 g/l of palladium.
Claim 10
Independent Claim
113 words
A method of manufacturing a catalyst for purifying exhaust gas, comprising the steps of: forming a first coating layer on a surface of a catalyst carrier; said first coating layer mainly consisting of active alumina containing platinum and rhodium; mixing solution of zirconium and solution of lanthanum with cerium so as to obtain a mixture; drying the mixture so as to obtain a solid matter; grinding the solid matter into a composite powder comprising oxides of zirconium and lanthanum are fixed on a surface of cerium oxide; and forming a second coating layer on a surface of said first coating layer; said second coating layer mainly consisting of the composite powder and palladium.
Claim 11
Independent Claim
113 words
A method of manufacturing a catalyst for purifying exhaust gas, comprising the steps of: forming a first coating layer on a surface of a catalyst carrier; said first coating layer mainly consisting of active alumina containing platinum and rhodium; mixing solution of zirconium and solution of lanthanum with cerium so as to obtain a mixture; drying the mixture so as to obtain a solid matter; grinding the solid matter into a composite powder comprising oxides of zirconium and lanthanum are fixed on a surface of cerium oxide; and forming a second coating layer on a surface of said first coating layer; said second coating layer mainly consisting of the composite powder and palladium.
Claim 12
Dependent Claim
17 words
A method as claimed in claim 9, wherein said catalyst carrier is formed in a honeycomb structure.
Claim 13
Dependent Claim
74 words
A method as claimed in claim 9, wherein said first coating layer is produced by the steps of: dipping said catalyst carrier in alumina slurry;. removing said catalyst carrier from the alumina slurry; drying and calcining said catalyst carrier so as to form said first coating layer on the surface of said catalyst carrier; impregnating a platinum compound and a rhodium compound in said first coating layer; and drying and calcining said catalyst carrier.
Claim 14
Dependent Claim
76 words
A method as claimed in claim 9, wherein said second coating layer is produced by the steps of: preparing a slurry of the composite powder; dipping in the slurry said catalyst carrier having said first coating layer formed thereon; removing said catalyst carrier from the slurry; drying and calcining said catalyst carrier; dipping said catalyst carrier in solution of palladium; removing said catalyst carrier from the solution of palladium; and drying and calcining said catalyst carrier.
Claim 15
Dependent Claim
57 words
A method as claimed in claim 9, wherein said second coating layer is produced by the steps of: preparing a slurry of the composite powder mixed with palladium compound; dipping in the slurry said catalyst carrier having said first coating layer formed thereon; removing said catalyst carrier from the slurry; and drying and calcining said catalyst carrier.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |