EP0152052A2
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EP
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Process for producing monolithic catalyst for purifying exhaust gases
Assignee: Nippon Shokubai Co Ltd
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Filing: 1985-02-05
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Granted: —
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Expires: 2005-02-05
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
- 👤 Ono Tetsuji
- 👤 Ichihara Shoichi
- 👤 Ohata Tomohisa
- 👤 Terui Sadao
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 15:00
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: 12
Claim 1
Independent Claim
53 words
A process for producing a monolithic catalyst for purification of exhaust gases, 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.
Claim 2
Dependent Claim
53 words
A process for producing a monolithic catalyst for purification of exhaust gases, 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.
Claim 3
Dependent Claim
71 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, dispersing the resulting material and a powder of cerium hydroxide in water, and coating the resulting aqueous slurry composition on a monolithic support.
Claim 4
Dependent Claim
71 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, dispersing the resulting material and a powder of cerium hydroxide in water, and coating the resulting aqueous slurry composition on a monolithic support.
Claim 5
Dependent Claim
25 words
The process of claim 1 or 2 wherein the amount of the cerium hydroxide powder supported is 5 to 100 g/liter of catalyst as Ce02.
Claim 6
Dependent Claim
45 words
The process of claim 1, 2 or 3 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 7
Dependent Claim
53 words
The process of claim 1, 2, 3 or 4 wherein together with cerium hydroxide, a lanthanum compound other than lanthanum carbonate is used in an amount of not more than 30% by weight, as La 2 0 3 , based on the total weight of CeO 2 and La 2 0 3 .
Claim 8
Dependent Claim
75 words
A process of any one of claims 1 to 5 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, and thereafter depositing a rhodium compound on the coated surface of the support.
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein the rhodium compound is a water-soluble rhodium compound.
Claim 10
Dependent Claim
35 words
The process of claim 6 or 7 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 11
Dependent Claim
112 words
A process of any one of claims 1 to 5 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 aqueous slurry composition on a monolithic support and then coating the second aqueous slurry composition on it.
Claim 12
Dependent Claim
37 words
The process of any one of claims 6 to 9 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.
References Cited (Backward Citations)
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