Patent US4624940A successfully refreshed from Google Patents.
US4624940A
Expired / Lapsed
US
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High temperature catalyst compositions for internal combustion engine
Assignee: BASF Catalysts LLC
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Filing: 1985-04-12
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Granted: 1986-11-25
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Expires: 2005-04-12
Abstract
Abstract Catalysts having three types of particles dispersed on a monolith have surprising oxidation and three-way activity even after exposure to temperatures above 1000° C. The particle types are: (1) palladium dispersed on stabilized alumina; (2) ceria-containing promoter particles and (3) washcoat stabilization particles.
Inventors
- 👤 Chung-Zong Wan
- 👤 Joseph C. Dettling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:50
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; B01J23/58; B01J37/00; B01J37/02; B01J37/024; B01J37/0248; B01J37/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
168 words
A catalyst effective at least for oxidation of carbon monoxide and unburned hydrocarbons in an exhaust stream, said catalyst remaining effective after exposure to a temperature greater than 1000° C., said catalyst comprising particles from each of the following three classes dispersed on a ceramic monolithic substrate: (a) stabilized gamma alumina support particles having palladium dispersed thereon, said gamma alumina support particles being stabilized by a method selected from the group consisting of: (i) incorporation of a combination of lanthana and baria into said particles and (ii) impregnation of said particles with an aqueous dispersion of a high molecular weight polyorganosiloxane followed by heating to a temperature which is effective to decompose said polyorganosiloxane; (b) promoter particles effective for promotion of combustion of carbon monoxide, said promoter consisting essentially of an oxide selected from the group consisting of bulk ceria, bulk zirconia and mixtures thereof; and (c) washcoat stabilization particles consisting essentially of a mixed oxide selected from the group consisting of cordierite, mullite, and magnesium aluminum titanate.
Claim 2
Dependent Claim
168 words
A catalyst effective at least for oxidation of carbon monoxide and unburned hydrocarbons in an exhaust stream, said catalyst remaining effective after exposure to a temperature greater than 1000° C., said catalyst comprising particles from each of the following three classes dispersed on a ceramic monolithic substrate: (a) stabilized gamma alumina support particles having palladium dispersed thereon, said gamma alumina support particles being stabilized by a method selected from the group consisting of: (i) incorporation of a combination of lanthana and baria into said particles and (ii) impregnation of said particles with an aqueous dispersion of a high molecular weight polyorganosiloxane followed by heating to a temperature which is effective to decompose said polyorganosiloxane; (b) promoter particles effective for promotion of combustion of carbon monoxide, said promoter consisting essentially of an oxide selected from the group consisting of bulk ceria, bulk zirconia and mixtures thereof; and (c) washcoat stabilization particles consisting essentially of a mixed oxide selected from the group consisting of cordierite, mullite, and magnesium aluminum titanate.
Claim 3
Dependent Claim
31 words
The catalyst of claim 1 wherein the weight of promoter dispersed on said substrate is at least about 5 percent of the total weight of the particles dispersed on said substrate.
Claim 4
Dependent Claim
39 words
The catalyst of claim 2 wherein the amount of palladium on the alumina particles dispersed on said monolithic substrate is sufficient to provide at least 5 grams of palladium per cubic foot of volume occupied by said monolithic substrate.
Claim 5
Dependent Claim
39 words
The catalyst of claim 2 wherein the amount of palladium on the alumina particles dispersed on said monolithic substrate is sufficient to provide at least 10 grams of palladium per cubic foot of volume occupied by said monolithic substrate.
Claim 6
Dependent Claim
39 words
The catalyst of claim 2 wherein the amount of palladium on the alumina particles dispersed on said monolithic substrate is sufficient to provide at least 15 grams of palladium per cubic foot of volume occupied by said monolithic substrate.
Claim 7
Dependent Claim
39 words
The catalyst of claim 1 wherein the amount of palladium on the alumina particles dispersed on said monolithic substrate is sufficient to provide at least 5 grams of palladium per cubic foot of volume occupied by said monolithic substrate.
Claim 8
Dependent Claim
33 words
The catalyst of claim 1 wherein the weight of CeO 2 promoter dispersed on said substrate is at least about 20 percent of the total weight of the particles dispersed on said substrate.
Claim 9
Dependent Claim
33 words
The catalyst of claim 1 wherein the weight of CeO 2 promoter dispersed on said substrate is at least about 25 percent of the total weight of the particles dispersed on said substrate.
Claim 10
Dependent Claim
72 words
The catalyst of any one of claims 1 through 8 wherein said monolithic substrate consists essentially of cordierite, mullite or magnesium aluminum titanate, said gamma alumina support particles are stabilized with a combination of lanthana and baria, said promoter particles consist essentially of ceria and said washcoat stabilization particles consist essentially of cordierite, the amount of lanthana and baria each being about at least 0.3% of the weight of the gamma alumina.
Claim 11
Dependent Claim
26 words
The catalyst of claim 9 wherein the ceria content of the gamma alumina particles upon which the palladium is deposited is less than 0.5% by weight.
Claim 12
Dependent Claim
63 words
The catalyst of claim 9 wherein the amount of stabilized gamma alumina on the monolithic substrate is from about 0.2 g/in 3 to about 5 g/in 3 , the amount of washcoat stabilization particles present on the monolith is from about 0.05 to about 1.0 g/in 3 and the amount of promoter present is between about 0.1 and about 2.0 g/in 3 .
Claim 13
Dependent Claim
85 words
The catalyst of any one of claims 1 through 8 wherein said monolithic substrate consists essentially of cordierite, mullite or magnesium aluminum titanate, said gamma alumina support particles have been stabilized by contacting with an aqueous dispersion of polyorganosiloxane and calcining, said promoter particles consist essentially of ceria or zirconia and said washcoat stabilization particles consist essentially of cordierite, the amount of SiO 2 remaining after calcining being from about 4 to 15% of the combined weight of the gamma alumina and SiO 2 .
Claim 14
Dependent Claim
26 words
The catalyst of claim 12 wherein the ceria content of the gamma alumina particles upon which the palladium is deposited is less than 0.5% by weight.
Claim 15
Dependent Claim
63 words
The catalyst of claim 12 wherein the amount of stabilized gamma alumina on the monolithic substrate is from about 0.2 g/in 3 to about 5 g/in 3 , the amount of washcoat stabilization particles present on the monolith is from about 0.05 to about 1.0 g/in 3 and the amount of promoter present is between about 0.1 and about 2.0 g/in 3 .
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) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |