US5354720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction in the quantity of NOx in lean exhaust gas of motor vehicle engines
Assignee: DMC2 Degussa Metals Catalysts Cerdec AG
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Filing: 1993-03-04
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Granted: 1994-10-11
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Expires: 2013-03-04
Abstract
Abstract A catalyst is described for reducing the quantity of nitrogen oxides in lean exhaust gas of motor vehicle engines. The catalyst contains, on a structure reinforcing body, a first catalytic coating of an aluminum oxide and/or cerium oxide of large surface area impregnated with a mixture of iridium and platinum as catalytically active noble metal components. A second catalytic coating including a zeolite of the mordenite type containing copper and/or iron is applied to the first coating layer.
Inventors
- 👤 Jurgen Leyrer
- 👤 Egbert Lox
- 👤 Bernd Engler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:11
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J21/00; B01J21/02; B01J21/04; B01J37/00; B01J37/02; B01J37/024; B01J37/0244; B01J37/0246; F; F02; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
A catalyst for reducing a quantity of nitrogen oxides in lean exhaust gas of motor vehicle engines, comprising: an inert, structure reinforcing body; a first catalytic coating on said body, the coating including aluminum oxide and/or cerium oxide of large surface area, optionally stabilized with rare earth metals and/or silicon dioxide, as a carrier for catalytically active noble metal components and noble metals including at least platinum and iridium; and a second catalytic coating of zeolite on the first catalytic coating; wherein the noble metal components of the first catalytic layer include iridium and platinum in a ratio by weight of from 1:10 to 10:1, and wherein the zeolite is a temperature stable zeolite of mordenite containing copper and/or iron, wherein the zeolite has an SiO 2 : Al 2 O 3 molar ratio in the range of 10-50.
Claim 2
Dependent Claim
139 words
A catalyst for reducing a quantity of nitrogen oxides in lean exhaust gas of motor vehicle engines, comprising: an inert, structure reinforcing body; a first catalytic coating on said body, the coating including aluminum oxide and/or cerium oxide of large surface area, optionally stabilized with rare earth metals and/or silicon dioxide, as a carrier for catalytically active noble metal components and noble metals including at least platinum and iridium; and a second catalytic coating of zeolite on the first catalytic coating; wherein the noble metal components of the first catalytic layer include iridium and platinum in a ratio by weight of from 1:10 to 10:1, and wherein the zeolite is a temperature stable zeolite of mordenite containing copper and/or iron, wherein the zeolite has an SiO 2 : Al 2 O 3 molar ratio in the range of 10-50.
Claim 3
Dependent Claim
37 words
A catalyst according to claim 1, wherein aluminum oxide and silicon dioxide are present, and the total SiO 2 content of the stabilized aluminum oxide is greater than 0.1% by weight, based on the aluminum oxide weight.
Claim 4
Dependent Claim
28 words
A catalyst according to claim 2, wherein the total SiO 2 content is in the range of 0.1 to 15% by weight, based on the aluminum oxide weight.
Claim 5
Dependent Claim
28 words
A catalyst according to claim 2, wherein the total SiO 2 content is in the range of 4.5 to 11.5% by weight, based on the aluminum oxide weight.
Claim 6
Dependent Claim
23 words
A catalyst according to claim 1, wherein the SiO 2 : Al 2 O 3 molar ratio is in the range of 15-30.
Claim 7
Dependent Claim
21 words
A catalyst according to claim 1, wherein the zeolite is charged with the elements copper and/or iron within its ion capacity.
Claim 8
Dependent Claim
29 words
A catalyst according to claim 6, wherein the zeolite contains a total of from 0.1 to 3.0% by weight copper and/or iron, based on the weight of the zeolite.
Claim 9
Dependent Claim
29 words
A catalyst according to claim 6, wherein the zeolite contains a total of from 1.0 to 7.5% by weight copper and/or iron, based on the weight of the zeolite.
Claim 10
Dependent Claim
30 words
A catalyst according to claim 7, wherein the zeolite contains at least 0.5% by weight and at most 5.5% by weight of copper, based on the weight of the zeolite.
Claim 11
Dependent Claim
30 words
A catalyst according to claim 8, wherein the zeolite contains at least 0.5% by weight and at most 5.5% by weight of copper, based on the weight of the zeolite.
Claim 12
Dependent Claim
30 words
A catalyst according to claim 7, wherein the zeolite contains at least 0.5% by weight and at most 7.5% by weight of iron, based on the weight of the zeolite.
Claim 13
Dependent Claim
30 words
A catalyst according to claim 8, wherein the zeolite contains at least 0.5% by weight and at most 7.5% by weight of iron, based on the weight of the zeolite.
Claim 14
Dependent Claim
17 words
A catalyst according to claim 1, wherein the structure reinforcing body is a ceramic or metallic carrier.
Claim 15
Dependent Claim
16 words
A catalyst according to claim 1, wherein the structure reinforcing body is a monolithic honeycomb carrier.
Claim 16
Dependent Claim
34 words
A catalyst according to claim 13, wherein both the first catalytic coating and the second catalytic coating are applied in a quantity in the range of from 50-150 grams per liter of catalyst volume.
Claim 17
Dependent Claim
34 words
A catalyst according to claim 14, wherein both the first catalytic coating and the second catalytic coating are applied in a quantity in the range of from 50-150 grams per liter of catalyst volume.
Claim 18
Dependent Claim
32 words
A catalyst according to claim 1, wherein the aluminum oxide and/or cerium oxide is formed into a layer on the structure reinforcing body, and then this layer is impregnated with noble metals.
Claim 19
Dependent Claim
34 words
A catalyst according to claim 1, wherein the aluminum oxide and/or cerium oxide and the noble metals are formed into a suspension, and the suspension forms the first coating on the structure reinforcing body.
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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) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |