US4900712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic washcoat and method of preparation of the same
Assignee: Prototech Inc
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Filing: 1988-09-30
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Granted: 1990-02-13
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Expires: 2008-09-30
Abstract
Abstract The invention is concerned with a method of adsorbing uniformly onto preformed high surface area crystalline alumina one or more catalytically active non-noble (doping) oxide(s) and preferably alumina-stablilizing non-noble doping oxide(s), both from substantially neutral aqueous colloidal solutions thereof, drying and calcining the doped alumina to form an improved washcoating composition for receiving additionally catalytic noble metal particles.
Inventors
- 👤 Amiram Bar-Ilan
- 👤 Martin E. Morrill, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:25
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/0215; B01J37/0221
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
91 words
The method of preparing a washcoating composition for use as a component of a catalytic coating which comprises the steps of preparing an aqueous colloidal solution of particles of one or more catalytically active non-noble metal doping oxide(s), contacting said solution with particles of a preformed washcoat base comprising a high surface area crystalline alumina, thereby uniformly adsorbing said doping particles thereon, limiting the amount of said doping oxide particles to amounts less than about 20% by weight of said doped preformed particles, and drying and calcining said doped preformed particles.
Claim 2
Independent Claim
91 words
The method of preparing a washcoating composition for use as a component of a catalytic coating which comprises the steps of preparing an aqueous colloidal solution of particles of one or more catalytically active non-noble metal doping oxide(s), contacting said solution with particles of a preformed washcoat base comprising a high surface area crystalline alumina, thereby uniformly adsorbing said doping particles thereon, limiting the amount of said doping oxide particles to amounts less than about 20% by weight of said doped preformed particles, and drying and calcining said doped preformed particles.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said solution is prepared as a stable substantially neutral colloidal solution.
Claim 4
Dependent Claim
53 words
The method of claim 1 wherein said solution is prepared as a freshly made transient colloidal solution, wherein preformed particles are stirred and wherein said solution is added promptly thereto, thereby causing its dopant oxide particles to be adsorbed uniformly by said alumina particles prior to coalescence and precipitation of said dopant oxides.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein at least two doping oxides are used.
Claim 6
Dependent Claim
29 words
The method of claim 4 wherein said doping oxides are selected from the group consisting of titania, zirconia, iron oxide, cerium oxide, lanthanum oxide, nickel oxide and chromium oxide.
Claim 7
Dependent Claim
35 words
The method of claim 5 wherein said solution comprises at least one of titania and zirconia whereby the surface area loss during sintering of said preformed particles under exposure to high temperatures is slowed substantially.
Claim 8
Dependent Claim
31 words
The method of claim 5 wherein said doping oxides in said solution comprise at least one oxide selected from ceria, chromium oxide, iron oxide and nickel oxide additionally having catalytic activity.
Claim 9
Dependent Claim
57 words
In a method of producing a catalytic structure comprising a support, a high surface area alumina-containing washcoat preformed thereon and a noble metal catalyst, the improvement of adsorbing onto said washcoat uniform particles of at least one catalytically active non-noble metal doping oxide and at least one alumina-stabilizing non-noble metal doping oxide, both from aqueous colloidal solutions.
Claim 10
Dependent Claim
57 words
In a method of producing a catalytic structure comprising a support, a high surface area alumina-containing washcoat preformed thereon and a noble metal catalyst, the improvement of adsorbing onto said washcoat uniform particles of at least one catalytically active non-noble metal doping oxide and at least one alumina-stabilizing non-noble metal doping oxide, both from aqueous colloidal solutions.
Claim 11
Dependent Claim
27 words
A method as claimed in claim 8 and in which said doping oxides are provided in amounts less than about 20% by weight of said doped washcoat.
Claim 12
Dependent Claim
17 words
The method of claim 1 and in which catalytic noble metal is applied to said doped washcoating.
Claim 13
Dependent Claim
42 words
A wash-coated catalytic support comprising a high surface area preformed crystalline alumina-containing washcoat base, a predominant amount of which carries uniformly adsorbed catalytically active colloidal particles of one or more non-noble metal doping oxides in amounts less than about 20% by weight.
Claim 14
Dependent Claim
42 words
A wash-coated catalytic support comprising a high surface area preformed crystalline alumina-containing washcoat base, a predominant amount of which carries uniformly adsorbed catalytically active colloidal particles of one or more non-noble metal doping oxides in amounts less than about 20% by weight.
Claim 15
Dependent Claim
19 words
A washcoated catalytic support as claimed in claim 11 and in which the adsorbed dopant oxide particles are calcined.
Claim 16
Dependent Claim
25 words
A washcoated catalytic support as claimed in claim 12 and in which said doping oxide comprises one of the colloidal particles of titania and zirconia.
Claim 17
Dependent Claim
23 words
A washcoated catalytic support as claimed in claim 12 and in which at least two doping oxides are adsorbed by said alumina particles.
Claim 18
Dependent Claim
53 words
A washcoated catalytic support as claimed in 12 and in which said doping oxides are selected from the group consisting of colloidal particle titania, zirconia, iron oxide, cerium oxide, lanthanum oxide, nickel oxide and chromium oxide adsorbed in amounts less than about 20% of the total weight of doping oxides and preformed particles.
Claim 19
Dependent Claim
22 words
A washcoated catalytic support as claimed in claim 12 and in which noble metal is deposited on said adsorbed doping oxide particles.
Claim 20
Dependent Claim
38 words
A washcoated catalytic support comprising a high surface area preformed crystalline alumina-containing washcoat base, a predominant amount of which carries, uniformly adsorbed, a catalytically active non-noble colloidal metal doping oxide and an alumina-stabilizing non-noble colloidal metal doping oxide.
Claim 21
Dependent Claim
38 words
A washcoated catalytic support comprising a high surface area preformed crystalline alumina-containing washcoat base, a predominant amount of which carries, uniformly adsorbed, a catalytically active non-noble colloidal metal doping oxide and an alumina-stabilizing non-noble colloidal metal doping oxide.
References Cited (Backward Citations)
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