EP0430435A2
Expired / Lapsed
EP
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Three-way catalyst for automotive emission control
Assignee: Ford-Werke GmbH
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Filing: 1990-10-25
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Granted: —
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Expires: 2010-10-25
Abstract
Abstract A three-way catalyst for automotive emission control having a mechanical carrier having a support comprised substantially of alumina, a catalytic compound supported on said carrier having a major constituent of palladium, and a discontinuous phase of titanium oxide on or adjacent substantially each exposed particle of the catalytic compound. A method of making a three-way catalyst for automotive emission control, comprising: impregnating with palladium a mechanical carrier having a support comprised substantially of alumina to produce a composite having .05-5.0% palladium; and impregnating the composite with an organo-titanium compound and decomposing such impregnated compound to form a discontinuous titanium oxide phase on or adjacent the exposed portions of said composite.
Inventors
- 👤 Mohinder Singh Chattha
- 👤 William Lewis Henderson Watkins
- 👤 Haren Sarkarlal Gandhi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 20:07
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/44; B01J37/00; B01J37/02; B01J37/024; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
48 words
A three-way catalyst for automotive emission control, comprising, a mechanical carrier having a support comprised substantially of alumina, a catalytic compound on said support having a major constituent of palladium, and a discontinuous phase of titanium oxide substantially on or adjacent each exposed particle of said catalytic compound.
Claim 2
Dependent Claim
48 words
A three-way catalyst for automotive emission control, comprising, a mechanical carrier having a support comprised substantially of alumina, a catalytic compound on said support having a major constituent of palladium, and a discontinuous phase of titanium oxide substantially on or adjacent each exposed particle of said catalytic compound.
Claim 3
Dependent Claim
25 words
A catalyst as claimed in claim 1, in which said carrier is a honeycomb-shaped monolith of cordierite of which alumina is the dominant support phase.
Claim 4
Dependent Claim
28 words
A catalyst as claimed in claim 1, in which said discontinuous titanuim oxide phase is a washcoat constituting up to 8% of the total weight of the catalyst.
Claim 5
Dependent Claim
21 words
A catalyst as claimed in claim 3, in which said catalytic compound forms .05-5.0% of the total weight of the catalyst.
Claim 6
Dependent Claim
25 words
A catalyst as claimed in claim 4, in which said catalytic compound contains palladium which is at least 55% of the weight of the compound.
Claim 7
Dependent Claim
31 words
A catalyst as claimed in claim 1, in which no greater than 40% of the surface area of each exposed particle of catalytic compound is covered by said titanium oxide phase.
Claim 8
Dependent Claim
20 words
A catalyst as claimed in claim 1, in which said discontinuous titanium oxide phase covers 2-20% of said catalytic compound.
Claim 9
Dependent Claim
23 words
A catalyst as claimed in claim 1, in which said discontinuous titanium oxide phase is .1-8.0% of the total weight of the catalyst.
Claim 10
Dependent Claim
23 words
A catalyst as claimed in claim 8, in which said discontinuous titanium oxide phase is .1-2.0% of the total weight of the catalyst.
Claim 11
Independent Claim
63 words
A method of making a three-way catalyst for automotive emission control, the method comprising, impregnating with palladium a mechanical carrier having a support comprised substantially of alumina to produce a composite having .05-5.0% palladium, and impregnating the composite with an organo-titanium compound and decomposing such impregnated compound to form a discontinuous titanium oxide phase on or adjacent the exposed portions of said composite.
Claim 12
Independent Claim
63 words
A method of making a three-way catalyst for automotive emission control, the method comprising, impregnating with palladium a mechanical carrier having a support comprised substantially of alumina to produce a composite having .05-5.0% palladium, and impregnating the composite with an organo-titanium compound and decomposing such impregnated compound to form a discontinuous titanium oxide phase on or adjacent the exposed portions of said composite.
Claim 13
Dependent Claim
56 words
A method as claimed in claim 10, in which palladium is added in a diluted palladium nitrate solution, with the amount of said acid being regulated to achieve pH of 3-5 and a discontinuous Pd coating, and after drying the carrier wetted with said acid, calcining the composite at a temperature in the range of 400-600°C.
Claim 14
Dependent Claim
36 words
A method as claimed in claim 10, in which said organo-titanium compound is dissolved in a liquid for wetting said composite, said wetted composite being calcined at a temperature of 400-600 o C for 4-12 hours.
Claim 15
Dependent Claim
35 words
A method as claimed in claim 12, in which said calcination is staged to include heating to 250-280 o C for 1-1/2 to 2-1/2 hours, and thence heating to 400-600 o C for 5-10 hours.
Claim 16
Dependent Claim
37 words
A method as claimed in claim 10, in which said support is coated prior to or simultaneously with the palladium impregnating step, with an oxide to aid dispersement of the catalyst compound or stabilization of the carrier.
Claim 17
Dependent Claim
27 words
A method as claimed in claim 14, in which said oxide is selected from the group consisting of an oxide of cerium, zirconium, barium, calcium and iron.
Claim 18
Dependent Claim
25 words
A method as claimed in claim 10, in which said carrier is a honeycomb-shaped monolith of cordierite, of which alumina is the dominant support coating.
Claim 19
Dependent Claim
65 words
A method as claimed in claim 10, in which said support is a collection of aggregates prepared by (i) wetting a particulate source of alumina with dilute nitric acid to form a slurry, (ii) drying said slurry to form a cake, and (iii) crushing said cake to an average particle size of 20-40 mesh and then ball milling the slurry before application to the carrier.
Claim 20
Dependent Claim
17 words
A method as claimed in claim 10, in which said discontinuous titanium in said oxide is tetravalent.
Claim 21
Dependent Claim
15 words
A method as claimed in claim 10, in which said organo-titanium compound is titanium butoxide.
References Cited (Backward Citations)
No citation records indexed.
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