US5063192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for purification of exhaust gases
Assignee: Mazda Motor Corp
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Filing: 1990-07-06
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Granted: 1991-11-05
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Expires: 2010-07-06
Abstract
Abstract A catalyst for the purification of exhaust gases contains a catalyst carrier with a first coat layer formed on a surface of the catalyst carrier and with a second coat layer formed on a surface of the first coat layer. The first coat layer contains an active alumina and a catalyst component comprised of a noble metal such as platinum and rhodium and at least one of zirconium oxide, lanthanum oxide and barium oxide is immobilized on particles of the active alumina, and the second coat layer contains an active alumina, cerium oxide and a catalyst component comprised of another noble metal such as palladium. The oxides of zirconium, lanthanum and/or barium can prevent the alumina particles from aggregating together due to heat, thereby improving heat resistance of the catalyst.
Inventors
- 👤 Hiroshi Murakami
- 👤 Kazuko Yamagata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:08
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01D53/9454; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/58; B01J23/63; B01J37/00; B01J37/02; B01J37/024; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
168 words
A catalyst for the purification of exhaust gases consisting essentially of a catalyst carrier with a first coat layer formed on a surface of the catalyst carrier and with a second coat layer formed on a surface of the first coat layer; wherein the first coat layer consists essentially of an active alumina and a catalyst component comprised of a noble metal and at least one of zirconium oxide, lanthanum oxide and barium oxide is immobilized on particles of the active alumina; the second coat layer consists essentially of an active alumina, cerium oxide and a catalyst component comprised of another noble metal, wherein a ratio of the weight of the active alumina to cerium oxide ranges from approximately 95 to 5 to approximately 70 to 30; and wherein said zirconium oxide, lanthanum oxide or barium oxide is contained in an amount ranging from 1% to 10% by weight based on the weight of a total wash coat of the first coat layer and the second coat layer.
Claim 2
Dependent Claim
168 words
A catalyst for the purification of exhaust gases consisting essentially of a catalyst carrier with a first coat layer formed on a surface of the catalyst carrier and with a second coat layer formed on a surface of the first coat layer; wherein the first coat layer consists essentially of an active alumina and a catalyst component comprised of a noble metal and at least one of zirconium oxide, lanthanum oxide and barium oxide is immobilized on particles of the active alumina; the second coat layer consists essentially of an active alumina, cerium oxide and a catalyst component comprised of another noble metal, wherein a ratio of the weight of the active alumina to cerium oxide ranges from approximately 95 to 5 to approximately 70 to 30; and wherein said zirconium oxide, lanthanum oxide or barium oxide is contained in an amount ranging from 1% to 10% by weight based on the weight of a total wash coat of the first coat layer and the second coat layer.
Claim 3
Dependent Claim
21 words
A catalyst as claimed in claim 1, wherein the noble metal contained in the first coat layer is platinum and/or rhodium.
Claim 4
Dependent Claim
20 words
A catalyst as claimed in claim 1, wherein said another noble metal contained in the second coat layer is palladium.
Claim 5
Dependent Claim
34 words
A catalyst as claimed in claim 1, wherein said noble metal contained in the first coat layer is platinum and rhodium and the another noble metal contained in the second coat layer is palladium.
Claim 6
Dependent Claim
41 words
A catalyst as claimed in claim 3, wherein cerium oxide contained in the second coat layer is contained in the amount ranging from 5% to 30% by weight based on the weight of the catalyst carrier and the first coat layer.
Claim 7
Dependent Claim
24 words
A catalyst as claimed in claim 1, wherein zirconium oxide, lanthanum oxide and barium oxide are immobilized on the particles of the active alumina.
Claim 8
Dependent Claim
22 words
A catalyst as claimed in claim 1, wherein zirconium oxide and lanthanum oxide are immobilized on the particles of the active alumina.
Claim 9
Dependent Claim
22 words
A catalyst as claimed in claim 1, wherein zirconium oxide and barium oxide are immobilized on the particles of the active alumina.
Claim 10
Dependent Claim
24 words
A catalyst as claimed in claim 4, wherein zirconium oxide, lanthanum oxide and barium oxide are immobilized on the particles of the active alumina.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-04 | 1995-05-06 | 1995-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-04 | 1999-05-06 | 1999-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-04 | 2003-05-06 | 2003-11-05 | $7700.00 | Window Closed / Lapsed |