US4367162A
Expired / Lapsed
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Catalyst for purifying exhaust gases and a method for producing the catalyst
Assignee: Toyota Central R&D Labs Inc
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Filing: 1981-03-04
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Granted: 1983-01-04
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Expires: 2001-03-04
Abstract
Abstract A catalyst for reducing nitrogen oxides, carbon monoxide and hydrocarbons, the noxious components in exhaust gases from internal combustion engines, etc., which comprises: a carrier having a substructure of refractory material in the form of a honeycomb structure, etc., and a porous layer of a powder formed on the surface thereof selected from the group consisting of a powder of zirconium oxide and a mixed powder of zirconium oxide powder with at least one powder selected from the group consisting of alumina, alumina-magnesia spinel and cerium oxide; and a catalyst ingredient supported thereon consisting of cerium oxide and a metal selected from the group consisting of platinum, palladium and mixtures thereof.
Inventors
- 👤 Yoshiyasu Fujitani
- 👤 Hideaki Muraki
- 👤 Shiroh Kondoh
- 👤 Makoto Tomita
- 👤 Tamotsu Nakamura
- 👤 Kouji Yokota
- 👤 Hideo Sobukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:44
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/06; B01J21/066; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/63; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
82 words
A catalyst for reducing nitrogen oxides, carbon monoxide and hydrocarbons, the noxious components in exhaust gases which comprises: a carrier having a substructure of refractory material and a porous layer of a powder formed on the surface thereof of zirconium oxide powder with at least one powder selected from the group consisting of alumina and alumina-magnesia spinel; and a catalyst ingredient supported thereon consisting essentially of cerium oxide and a metal selected from the group consisting of platinum, palladium and mixtures thereof.
Claim 2
Dependent Claim
82 words
A catalyst for reducing nitrogen oxides, carbon monoxide and hydrocarbons, the noxious components in exhaust gases which comprises: a carrier having a substructure of refractory material and a porous layer of a powder formed on the surface thereof of zirconium oxide powder with at least one powder selected from the group consisting of alumina and alumina-magnesia spinel; and a catalyst ingredient supported thereon consisting essentially of cerium oxide and a metal selected from the group consisting of platinum, palladium and mixtures thereof.
Claim 3
Dependent Claim
26 words
The catalyst according to claim 1, wherein said substructure of refractory material is one selected from the group consisting of cordierite, mullite, silicon carbide and α-alumina.
Claim 4
Dependent Claim
29 words
The catalyst according to claim 1, wherein alumina as one of the mixed powder used for the porous layer is selected from the group consisting of α-alumina and δ-alumina.
Claim 5
Dependent Claim
25 words
The catalyst according to claim 1, wherein the form of said substructure is one selected from the group consisting of honeycomb structures, pillars and pellets.
Claim 6
Dependent Claim
26 words
The catalyst according to claim 1, wherein said porous layer formed on the substructure amounts to 5 to 40 percent by weight relative to said substructure.
Claim 7
Dependent Claim
23 words
The catalyst according to claim 1, wherein the thickness of said porous layer formed on the substructure is from 0.05 to 0.5 mm.
Claim 8
Dependent Claim
21 words
The catalyst according to claim 1, wherein an average pore diameter of said porous layer is from 0.01 to 2 microns.
Claim 9
Dependent Claim
32 words
The catalyst according to claim 1, wherein the amount of cerium oxide as a catalyst ingredient supported on said carrier is from 5 g to 100 g per liter of said carrier.
Claim 10
Dependent Claim
28 words
The catalyst according to claim 1, wherein the amount of said metal supported on said carrier is from 0.01 g to 50 g per liter of said carrier.
Claim 11
Dependent Claim
107 words
A method for producing the catalyst of claim 1, which comprises: dipping a substructure in a slurry of zirconium oxide powder with at least one powder selected from the group consisting of alumina and alumina-magnesia spinel, a binder and water to adhere the powder to the surface of the substructure; drying the powder adhered to the substructure; sintering the powder by heating at 600° C. to 900° C. to form a porous layer on the surface of the substructure as a carrier; and supporting cerium oxide and a metal selected from the group consisting of platinum, palladium and mixtures thereof as a catalyst ingredient on the carrier.
Claim 12
Dependent Claim
49 words
The method according to claim 10, wherein the step of supporting cerium oxide and said metal on the porous layer comprises: impregnating the porous layer formed on the substructure with a solution of raw material forming each of the catalyst ingredients; drying the impregnated porous layer; and calcining it.
Claim 13
Dependent Claim
32 words
The method according to claim 11, wherein said raw material of cerium oxide as a catalyst ingredient is one selected from the group consisting of cerium (III) nitrate and cerium (III) chloride.
Claim 14
Dependent Claim
29 words
The method according to claim 11, wherein said raw material of platinum as a catalyst ingredient is one selected from the group consisting of platinum nitrate and chloroplatinic acid.
Claim 15
Dependent Claim
26 words
The method according to claim 11, wherein said raw material of palladium as a catalyst ingredient is one selected from the group consisting of palladium nitrate.
Claim 16
Dependent Claim
26 words
The method according to claim 10, wherein said porous layer formed on the substructure amounts to 5 to 40 percent by weight relative to said substructure.
Claim 17
Dependent Claim
23 words
The method according to claim 10, wherein the thickness of said porous layer formed on the substructure is from 0.05 to 0.5 mm.
Claim 18
Dependent Claim
21 words
The method according to claim 10, wherein an average pore diameter of said porous layer is from 0.01 to 2 microns.
Claim 19
Dependent Claim
32 words
The method according to claim 10, wherein the amount of cerium oxide as a catalyst ingredient supported on said carrier is from 5 g to 100 g per liter of said carrier.
Claim 20
Dependent Claim
28 words
The method according to claim 10, wherein the amount of said metal supported on said carrier is from 0.01 g to 50 g per liter of said carrier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |