EP0211233A1
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EP
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Exhaust gas cleaning catalyst and process for production thereof
Assignee: Nippon Shokubai Co Ltd
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Filing: 1986-07-01
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Granted: —
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Expires: 2006-07-01
Abstract
Abstract An exhaust gas cleaning catalyst composed of a refractory three-dimensional structure and a catalytically active substance supported thereon. That surface or part of the catalystwhich makes contact with an exhaust gas is formed of numerous irregularly arranged protrusions composed of a refractory inorganic powder having a particle diameter of 5to 300 micrometers or a mixture of it with refractory inorganic fibers and the catalytically active substance supported on the protrusions. The catalyst can be produced, for example, by preparing an aqueous slurry from the refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with the refractory inorganic fibers and a suitable dispersant, forming numerous irregularly arranged protrusions on that surface or part of a refractory three-dimensional structure which makes contact with an exhaust gas by using the resulting slurry, drying the structure option- allyfollowed by calcination, depositing the catalytically active substance, and drying the calcining and resulting structure.
Inventors
- 👤 Koichi Saito
- 👤 Kenji Ueda
- 👤 Yasuo Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 21:53
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; B01D39/2003; B01D39/2017; B01D39/2027; B01D39/2041; B01D39/2051; B01D39/2072; B01D39/2082; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/944; B01J; B01J37/00; B01J37/02; B01J37/024; B01D2239/00; B01D2239/04; B01D2239/0442; B01D2239/0471; B01D2239/0478; B01D2239/06; B01D2239/0645; B01D2239/10; B01D2239/12; B01D2239/1225; B01D2239/1233; B01D2239/1241; B01J35/00; B01J35/50; B01J35/56
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
An exhaust gas cleaning catalyst composed of a refractory three-dimensional structure and a catalytically active substance supported thereon, wherein that surface or part of the catalyst which makes contact with an exhaust gas is formed of numerous irregularly arranged . protrusions composed of a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers and the catalytically active substance supported on the protrusions.
Claim 2
Dependent Claim
74 words
An exhaust gas cleaning catalyst composed of a refractory three-dimensional structure and a catalytically active substance supported thereon, wherein that surface or part of the catalyst which makes contact with an exhaust gas is formed of numerous irregularly arranged . protrusions composed of a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers and the catalytically active substance supported on the protrusions.
Claim 3
Dependent Claim
31 words
The catalyst of claim 1 wherein the refractory three-dimensional structure is a ceramic foam, an open- flow ceramic honeycomb, a wall-flow honeycomb monolithic body, a metal honeycomb or a metal foam.
Claim 4
Dependent Claim
80 words
The catalyst of claim 1 wherein the refractory three-dimensional structure is a ceramic monolithic wall-flow honeycomb composed of a number of gas flow channels in which the flow channels are composed of channels having an open inlet portion and a closed outlet portion and channels having a closed inlet portion and an open outlet portion alternately and adjacently arranged and the flow channel walls adjacent to each other are composed of a porous partition wall having a gas filter function.
Claim 5
Dependent Claim
39 words
The catalyst of claim 1 wherein the refractory inorganic powder is a powder of at least one material selected from the group consisting of active alumina, silica, titania, zirconia, silica-alumina, alumina- zirconia, alumina-titania, silica-titania, silica- zirconia, titania-zirconia and zeolite.
Claim 6
Dependent Claim
49 words
The catalyst of claim 1 wherein the refractory inorganic fibers are at least one kind of fibers selected from the group consisting of fibers and whiskers of glass, alumina, silica, silicon nitride (Si3N4)' silicon carbide (SiC), potassium titanate, rock wool, zirconia, titanium carbide, iron, nickel, tungsten and calcium phosphate.
Claim 7
Dependent Claim
37 words
The catalyst of claim 1 wherein the average diameter and average length of the refractory inorganic fibers are from 1/300 to 1/5, and from 1/10 to 20 times the average particle diameter of refractory inorganic powder, respectively.
Claim 8
Dependent Claim
28 words
The catalyst of claim 1 wherein the weight ratio of the refractory inorganic powder and the refractory inorganic fibers is in the range of from 1:0.05 to 1:1.
Claim 9
Dependent Claim
42 words
The catalyst of claim 1 wherein the catalytically active substance is at least one substance selected from the group consisting of platinum, rhodium, palladium, vanadium, iron, cobalt, nickel, molybdenum, tungsten, niobium, phosphorus, lead, zinc, tin, copper, chromium, manganese, cerium, lanthanum and silver.
Claim 10
Dependent Claim
15 words
The catalyst of claim 8 wherein the catalytically active substance is platinum, rhodium, or palladium.
Claim 11
Dependent Claim
65 words
The catalyst of claim 1 wherein the catalytically active substance is a mixture of at least one element selected from the group consisting of platinum, rhodium and palladium and at least one element selected from the group consisting of vanadium, iron, cobalt, nickel, molybdenum, tungsten, niobium, phosphorus, lead, zinc, tin, copper, chromium, manganese, cerium, lanthanum, silver, barium, magnesium, calcium, strontium, potassium, sodium, cesium and rubidium.
Claim 12
Dependent Claim
120 words
ll. A process for producing an exhaust gas cleaning catalyst comprising a refractory three-dimensional structure and a catalytically active substance supported thereon, which comprises depositing the catalytically active substance on a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers, preparing an aqueous slurry from the resulting structure and at least one dispersant selected from the group consisting of alumina sol, titania sol, zirconia sol, silica sol, soluble boehmite and soluble organic polymer compounds, forming numerous irregularly arranged protrusions on that surface or part of the refractory three-dinmensional structure which makes contact with an exhaust gas by using the resulting slurry, and drying and calcining the resulting structure.
Claim 13
Dependent Claim
120 words
ll. A process for producing an exhaust gas cleaning catalyst comprising a refractory three-dimensional structure and a catalytically active substance supported thereon, which comprises depositing the catalytically active substance on a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers, preparing an aqueous slurry from the resulting structure and at least one dispersant selected from the group consisting of alumina sol, titania sol, zirconia sol, silica sol, soluble boehmite and soluble organic polymer compounds, forming numerous irregularly arranged protrusions on that surface or part of the refractory three-dinmensional structure which makes contact with an exhaust gas by using the resulting slurry, and drying and calcining the resulting structure.
Claim 14
Dependent Claim
124 words
A process for producing an exhaust gas cleaning catalyst comprising a refractory three-dimensional structure and a catalytically active substance supported thereon, which comprises preparing an aqueous slurry from a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers and at least one dispersant selected from the group consisting of alumina sol, titania sol, zirconia sol, silica sol, soluble boehmite and soluble organic polymeric compounds, forming numerous irregularly arranged protrusions on that surface or part of the refractory three-dimensional structure which makes contact with an exhaust gas by using the resulting slurry, drying the structure, optionally calcining it, depositing the catalytically active substance on the structure, and drying and calcining the resulting structure.
Claim 15
Dependent Claim
124 words
A process for producing an exhaust gas cleaning catalyst comprising a refractory three-dimensional structure and a catalytically active substance supported thereon, which comprises preparing an aqueous slurry from a refractory inorganic powder having a particle diameter of 5 to 300 micrometers or a mixture of it with refractory inorganic fibers and at least one dispersant selected from the group consisting of alumina sol, titania sol, zirconia sol, silica sol, soluble boehmite and soluble organic polymeric compounds, forming numerous irregularly arranged protrusions on that surface or part of the refractory three-dimensional structure which makes contact with an exhaust gas by using the resulting slurry, drying the structure, optionally calcining it, depositing the catalytically active substance on the structure, and drying and calcining the resulting structure.
References Cited (Backward Citations)
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