US4619909A
Expired / Lapsed
US
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Process for producing monolithic catalyst for purifying exhaust gases
Assignee: Nippon Shokubai Co Ltd
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Filing: 1985-02-08
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Granted: 1986-10-28
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Expires: 2005-02-08
Abstract
Abstract A monolithic catalyst for purification of exhaust gases is produced by a process which comprises coating a monolithic support with an aqueous slurry composition comprising a powder of active alumina, at least one compound of a platinum-group element selected from the group consisting of platinum, palladium and rhodium, and a powder of cerium hydroxide.
Inventors
- 👤 Tetsuji Ono
- 👤 Shoichi Ichihara
- 👤 Tomohisa Ohta
- 👤 Sadao Terui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:40
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J23/40; B01J23/63; B01J37/00; B01J37/02; B01J37/024; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
80 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing at least one compound of a platinum-group element selected from the group consisting of platinum, palladium and rhodium on a powder of active alumina, then fixing the platinum-group element to the active alumina by calcination or reduction, dispersing the resulting material and a powder of cerium hydroxide in water, coating the resulting aqueous slurry composition on a monolithic support, and drying the coating monolithic support.
Claim 2
Dependent Claim
80 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing at least one compound of a platinum-group element selected from the group consisting of platinum, palladium and rhodium on a powder of active alumina, then fixing the platinum-group element to the active alumina by calcination or reduction, dispersing the resulting material and a powder of cerium hydroxide in water, coating the resulting aqueous slurry composition on a monolithic support, and drying the coating monolithic support.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the amount of the cerium hydroxide powder supported is 5 to 100 g/liter of catalyst as CeO 2 .
Claim 4
Dependent Claim
42 words
The process of claim 1 wherein the cerium hydroxide powder has a primary particle diameter of substantially 0.1 to 0.8 micron, a secondary particle diameter of substantially 0.3 to 20 microns, and a water content of not more than 40% by weight.
Claim 5
Dependent Claim
49 words
The process of claim 1 wherein together with cerium hydroxide, a lanthanum compound other than lantonum carbonate is used in an amount of not more than 30% by weight, as La 2 O 3 , based on the total weight of CeO 2 and La 2 O 3 .
Claim 6
Dependent Claim
99 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing a platinum compound and/or a palladium compound and optionally a rhodium compound on a powder of active alumina, then fixing the platinum-group element or elements to active alumina, dispersing the resulting material and a powder of cerium hydroxide in water, coating the resulting aqueous slurry composition on a monolithic support followed by drying and calcining the coated monolithic support followed by drying and calcining the coated monolithic support and thereafter depositing a rhodium compound on the coated surface of the support followed by drying.
Claim 7
Dependent Claim
99 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing a platinum compound and/or a palladium compound and optionally a rhodium compound on a powder of active alumina, then fixing the platinum-group element or elements to active alumina, dispersing the resulting material and a powder of cerium hydroxide in water, coating the resulting aqueous slurry composition on a monolithic support followed by drying and calcining the coated monolithic support followed by drying and calcining the coated monolithic support and thereafter depositing a rhodium compound on the coated surface of the support followed by drying.
Claim 8
Dependent Claim
14 words
The process of claim 5 wherein the rhodium compound is a water-soluble rhodium compound.
Claim 9
Dependent Claim
33 words
The process of claim 5 wherein the rhodium compound is deposited by using an ammoniacal alkaline aqueous solution of a water-soluble rhodium compound having a pH in the range of 6 to 8.
Claim 10
Dependent Claim
126 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing a platinum compound and/or a palladium compound and optionally a rhodium compound on a powder of active alumina, then fixing the platinum-group element or elements to the active alumina, dispersing the resulting material and a powder of cerium hydroxide in water to prepare a first aqueous slurry composition, separately depositing a rhodium compound on a powder of active alumina, then fixing rhodium to the active alumina, dispersing the resulting material in water to form a second aqueous slurry composition, coating the first aqeuous slurry composition on a monolithic support followed by drying and calcining the coated monolithic support and then coating the second aqueous slurry composition on it, followed by drying.
Claim 11
Dependent Claim
126 words
A process for producing a monolithic catalyst for purification of exhaust gases, which comprises depositing a platinum compound and/or a palladium compound and optionally a rhodium compound on a powder of active alumina, then fixing the platinum-group element or elements to the active alumina, dispersing the resulting material and a powder of cerium hydroxide in water to prepare a first aqueous slurry composition, separately depositing a rhodium compound on a powder of active alumina, then fixing rhodium to the active alumina, dispersing the resulting material in water to form a second aqueous slurry composition, coating the first aqeuous slurry composition on a monolithic support followed by drying and calcining the coated monolithic support and then coating the second aqueous slurry composition on it, followed by drying.
Claim 12
Dependent Claim
32 words
The process of claim 8 wherein the amount of rhodium compound deposited in the final step is 1/2 to 1 times the amount of the rhodium compound supported on the finished catalyst.
Claim 13
Dependent Claim
38 words
The process of any one of claims 1, 5 or 8 wherein the fixing of said platinum-group element to said alumina is by means of reduction of said platinum-group element with a reducing agent in a wet state.
Claim 14
Dependent Claim
47 words
The process of any one of claims 1, 5 or 8 wherein said platinum-group element is fixed to said alumina and said slurries are fixed to said monolithic support by drying at a temperature of not more than 200° C. and calcining at 200° to 900° C.
Claim 15
Dependent Claim
15 words
The process of claim 11 wherein calcination is carried out at 300° to 700° C.
References Cited (Backward Citations)
US4231893A
Cited
JPS5626547A
Cited
JPS5756041A
Cited
JPS5787839A
Cited
US4528279A
Cited
US4331565A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |