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US5073532A
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Catalyst for purifying exhaust gases from internal combustion engines and method of making the catalyst
Assignee: DMC2 Degussa Metals Catalysts Cerdec AG
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Filing: 1990-07-30
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Granted: 1991-12-17
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Expires: 2010-07-30
Abstract
Abstract A catalyst is described made of active aluminum oxide with additives of CeO2, ZrO2, and Fe2O3 and/or NiO as carrier and an active phase, applied thereon and consisting of platinum, palladium and/or rhodium, and a base metal, which is obtainable by impregnation of the additive-containing carrier with solutions of salts of the metals for the active phase, wherein the base metal of the active phase is cerium, by drying, and by heating to 250 DEG to 650 DEG C. The catalyst can be used for the oxidation and/or reduction of exhaust gases from internal combustion engines.
Inventors
- 👤 Rainer Domesle
- 👤 Bernd Engler
- 👤 Edgar Koberstein
- 👤 Peter Schubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:04
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J23/54; B01J23/56; B01J23/63; B01J23/70; B01J23/89; B01J23/8933; B01J23/894; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
196 words
A method of making a catalyst for the purification of exhaust gases from internal combustion engines comprising forming a support by impregnating aluminum oxide from the transition series with an aqueous solution of a cerium salt and a zirconium salt and optionally an iron salt and/or a nickel salt, or impregnating with an aqueous suspension of oxides, hydroxides, or carbonates of cerium, zirconium, and optionally iron and/or nickel; tempering the support by heating in air at a temperature from 500 to 900°, impregnating the support with an aqueous solution of a salt or a noble metal and a base metal wherein the noble metal is platinum, palladium or rhodium or mixtures thereof and the base metal is cerium, the amount of noble metal component being from 0.03 to 3 weight percent and the amount of cerium being 0.01 to 150% by weight based on the total weight of the noble metal and cerium in the form of cerium oxide being an amount from 0.0007 to 0.35 gram per liter of carrier volume, contacting the so impregnated support with a hydrogen gas stream at a temperature from 250 to 650° C. and thereby forming the carrier catalyst.
Claim 2
Independent Claim
196 words
A method of making a catalyst for the purification of exhaust gases from internal combustion engines comprising forming a support by impregnating aluminum oxide from the transition series with an aqueous solution of a cerium salt and a zirconium salt and optionally an iron salt and/or a nickel salt, or impregnating with an aqueous suspension of oxides, hydroxides, or carbonates of cerium, zirconium, and optionally iron and/or nickel; tempering the support by heating in air at a temperature from 500 to 900°, impregnating the support with an aqueous solution of a salt or a noble metal and a base metal wherein the noble metal is platinum, palladium or rhodium or mixtures thereof and the base metal is cerium, the amount of noble metal component being from 0.03 to 3 weight percent and the amount of cerium being 0.01 to 150% by weight based on the total weight of the noble metal and cerium in the form of cerium oxide being an amount from 0.0007 to 0.35 gram per liter of carrier volume, contacting the so impregnated support with a hydrogen gas stream at a temperature from 250 to 650° C. and thereby forming the carrier catalyst.
Claim 3
Dependent Claim
147 words
A catalyst for purifying exhaust gases from internal combustion engines comprising a support composed of aluminum oxide from the transition series, which contains 5 to 70 weight % CeO 2 and 1.6 to 1.9 weight % ZrO 2 , 1 to 10 weight % Fe 2 O 3 , and 0 to 20 weight % NiO 2 , and a catalytically active phase deposited on the support, said phase consisting of 0.03 to 3 weight % of a noble metal selected from the group of platinum, palladium and rhodium or mixtures thereof, in combination with a base metal, cerium, the amount of cerium being 0.01 to 150% by weight, based on the total weight of noble metal and cerium in the form of cerium oxide being an amount from 0.0007 to 0.35 gram per liter of carrier volume; said catalyst produced by the method of claim 1.
Claim 4
Dependent Claim
21 words
The catalyst according to claim 2 wherein the weight ratio of platinum and/or palladium to the rhodium is 2:1 to 20:1.
Claim 5
Dependent Claim
23 words
The catalyst according to claim 2 which is produced by impregnating the support with an aqueous solution comprising a cerium and zirconium salt.
Claim 6
Dependent Claim
21 words
The catalyst according to claim 4 wherein the solution also contains an iron salt or a nickel salt, or mixture thereof.
Claim 7
Dependent Claim
28 words
The catalyst according to claim 2 wherein the support is mixed with an aqueous suspension of the oxides or hydroxides or carbonates of cerium, zirconium, iron and nickel.
Claim 8
Dependent Claim
22 words
The catalyst according to claim 4 wherein the support after impregnation is tempered in air by heating to 500 to 900° C.
Claim 9
Dependent Claim
35 words
The catalyst according to claim 4 wherein after impregnating, an additional impregnating of the support is done with an aqueous solution of a salt of the noble metal and the base metal and then drying.
Claim 10
Dependent Claim
23 words
The catalyst according to claim 2 wherein the support is treated in a hydrogen-containing gas stream at temperatures from 250 to 650° C.
Claim 11
Dependent Claim
12 words
The catalyst according to claim 2 deposited on a honeycomb ceramic substrate.
Claim 12
Dependent Claim
12 words
The catalyst according to claim 2 deposited on a honeycomb metal substrate.
Claim 13
Dependent Claim
26 words
The catalyst according to claim 2 wherein the catalytically active phase is present in an amount of 5 to 30% by weight based on the support.
Claim 14
Dependent Claim
12 words
The catalyst according to claim 2 wherein the support is lattice-stabilized alumina.
Claim 15
Dependent Claim
20 words
The method according to claim 13 wherein the support is deposited on a honeycomb shaped carrier of ceramic or metal.
Claim 16
Dependent Claim
9 words
A catalyst produced by the method of claim 14.
Claim 17
Dependent Claim
27 words
The method of claim 13 wherein said impregnated support is contacted with a hydrogen gas stream at a temperature from 250 to 650° C. for 4 hours.
Claim 18
Dependent Claim
131 words
A catalyst of improved light off behavior for purifying exhaust gases from internal combustion engines comprising a support composed of aluminum oxide from the transition series, which contains 5 to 70 weight % CeO 2 and 1.6 to 1.9 weight % ZrO 2 , 0 to 10 weight % Fe 2 O 3 , and 0 to 20 weight % NiO 2 , and a catalytically active phase deposited on the support, said phase consisting of 0.03 to 3 weight % of a noble metal selected from the group of platinum, palladium and rhodium or mixtures thereof, in combination with a base metal, cerium, the amount of cerium being 0.01 to 150% by weight, based on the total weight of noble metal; said catalyst produced by the method of claim 1.
Claim 19
Dependent Claim
34 words
A method of improving the lean activity of catalysts for purifying exhaust gases from internal combustion engines, said method comprises contacting the catalyst of claim 2 with said exhaust gases for conversion of pollutants.
References Cited (Backward Citations)
US4239656A
Cited
DE2907106A1
Cited
US4299734A
Cited
US4316822A
Cited
US4367166A
Cited
US4617794A
Cited
US4801620A
Cited
US4661329A
Cited
US4957710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |