US5292991A
Expired / Lapsed
US
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Process for removal of hydrocarbons carbon manoxide, and oxides of nitrogen from oxygen-containing waste gas using molecular sieve-palladium-platinum catalyst on a substrate
Assignee: Corning Inc
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Filing: 1993-03-10
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Granted: 1994-03-08
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Expires: 2013-03-10
Abstract
Abstract A process of using a catalyst system for the oxidation of hydrocarbons, carbon monoxide, and the reduction of nitrogen oxides is provided. The unique synergy of the catalyst system, a combination of molecular sieves and noble metals, provides a system that partially or entirely replaces the need for rhodium as a catalyst in three way catalyst systems.
Inventors
- 👤 Irwin M. Lachman
- 👤 Mallanagouda D. Patil
- 👤 Louis S. Socha, Jr.
- 👤 Srinivas H. Swaroop
- 👤 Raja R. Wusirika
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:50
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/064; B01J29/068; B01J37/00; B01J37/02; B01J37/024; B01J37/0246; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
148 words
A process for the removal of hydrocarbons, carbon monoxide, and oxides of nitrogen from oxygen-containing waste gas comprising: A) providing a substrate supporting a catalyst, the catalyst comprising a washcoat consisting of: (1) zeolite selected from the group consisting of ZSM zeolite and silicalite, the zeolite being mixed with high surface area oxide, and (2) a noble metal, the noble metal selected from the group consisting of platinum and palladium, the washcoat being characterized in that substantially all of the noble metal is sited on the high surface area oxide such that both the noble metal and the zeolite are available to catalyze reactants in the waste gas most suited for their respective properties; and B) contacting the waste gas with the noble metal and the zeolite to oxidize hydrocarbons and carbon monoxide to carbon dioxide and water, and to reduce oxides of nitrogen to nitrogen and water.
Claim 2
Dependent Claim
148 words
A process for the removal of hydrocarbons, carbon monoxide, and oxides of nitrogen from oxygen-containing waste gas comprising: A) providing a substrate supporting a catalyst, the catalyst comprising a washcoat consisting of: (1) zeolite selected from the group consisting of ZSM zeolite and silicalite, the zeolite being mixed with high surface area oxide, and (2) a noble metal, the noble metal selected from the group consisting of platinum and palladium, the washcoat being characterized in that substantially all of the noble metal is sited on the high surface area oxide such that both the noble metal and the zeolite are available to catalyze reactants in the waste gas most suited for their respective properties; and B) contacting the waste gas with the noble metal and the zeolite to oxidize hydrocarbons and carbon monoxide to carbon dioxide and water, and to reduce oxides of nitrogen to nitrogen and water.
Claim 3
Dependent Claim
25 words
The process of claim 1, wherein the catalyst consists essentially of 1-95 wt. % zeolite, the balance being high surface area oxide and noble metal.
Claim 4
Dependent Claim
24 words
The process of claim 1, wherein the catalyst consists of 5-60 g/ft 3 noble metal, the balance being high surface area oxide and zeolite.
Claim 5
Dependent Claim
18 words
The process of claim 1, wherein the zeolite is grown on seeds and integrally supported by the substrate.
Claim 6
Dependent Claim
42 words
The process of claim 1, wherein the substrate is a ceramic honeycomb selected from a group consisting of: cordierite, mullite, alumina, titania, zircon, feldspar, quartz, fused silica, clay, aluminum titanate solid solution, silicate, aluminate, zirconia, spinel, glass, glass-ceramic and a combination thereof.
Claim 7
Dependent Claim
12 words
The process of claim 1, wherein the substrate is a metal honeycomb.
Claim 8
Dependent Claim
10 words
The process of claim 6, wherein the metal is preoxidized.
Claim 9
Dependent Claim
34 words
The process of claim 6, wherein the substrate is formed of a sintered powder selected from the group consisting of aluminum, copper, iron, magnesium, nickel, titanium, alloys of these metals, silicon, and stainless steel.
Claim 10
Dependent Claim
29 words
The process of claim 1, wherein the high surface area oxide is selected from the group consisting of hydrolyzed aluminum alkoxide, aluminum chlorhydrate, silica, alumina, zirconia, spinel, and titania.
Claim 11
Dependent Claim
32 words
The process of claim 9, wherein the high surface area oxide is a pseudo-boehmite alumina which has been converted to gamma alumina by firing in the range of 500° to 600° C.
Claim 12
Dependent Claim
25 words
The process of claim 1, wherein the washcoat comprises alumina and silicalite in a silicalite to alumina ratio in the range of 4:1 to 6:1.
Claim 13
Dependent Claim
11 words
The process of claim 5, wherein the silicate is lithium aluminosilicate.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |