US4239656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for purifying exhaust gases and carrier for the catalyst
Assignee: Toyota Central R&D Labs Inc
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Filing: 1979-04-04
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Granted: 1980-12-16
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Expires: 1999-04-04
Abstract
Abstract A catalyst for removing nitrogen oxide, carbon monoxide and hydrocarbon impurities from exhaust gases comprising a porous carrier consisting essentially of alumina-magnesia spinel; and a metal supported thereon selected from the group consisting of platinum, palladium and mixtures thereof.
Inventors
- 👤 Yoshiyasu Fujitani
- 👤 Hideaki Muraki
- 👤 Shiroh Kondoh
- 👤 Kouji Yokota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:45
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/40; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10S; Y10S502/00; Y10S502/524
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
63 words
A catalyst for reducing nitrogen oxide, carbon monoxide and hydrocarbons in exhaust gases, consisting essentially of: a porous alumina-magnesia spinel carrier containing from 0.05 to 20% by weight of ceria based on the spinel, said porous carrier having an average pore diameter of 0.01 to 2 microns; and a metal supported thereon selected from the group consisting of platinum, palladium and mixtures thereof.
Claim 2
Dependent Claim
63 words
A catalyst for reducing nitrogen oxide, carbon monoxide and hydrocarbons in exhaust gases, consisting essentially of: a porous alumina-magnesia spinel carrier containing from 0.05 to 20% by weight of ceria based on the spinel, said porous carrier having an average pore diameter of 0.01 to 2 microns; and a metal supported thereon selected from the group consisting of platinum, palladium and mixtures thereof.
Claim 3
Dependent Claim
25 words
The catalyst of claim 1, wherein the porous carrier contains 1 to 25% by weight of each of alumina and magnesia based on the spinel.
Claim 4
Dependent Claim
48 words
The catalyst of claim 1, wherein the porous carrier contains from 1 to 25% by weight of each of alumina and magnesia based on the spinel and from 0.05 to 20% by weight of ceria based on the total weight of said spinel, said alumina and said magnesia.
Claim 5
Dependent Claim
22 words
The catalyst of claim 1, wherein the content of the metal is from 0.01 to 5% by weight of the porous carrier.
Claim 6
Dependent Claim
50 words
A carrier for a catalyst used for reducing nitrogen oxide, carbon monoxide and hydrocarbons in exhaust gases, which consists essentially of: a porous alumina-magnesia spinel body containing 0.05 to 20% by weight ceria based on the spinel, said porous body having an average pore diameter of 0.01 to 2 microns.
Claim 7
Dependent Claim
50 words
A carrier for a catalyst used for reducing nitrogen oxide, carbon monoxide and hydrocarbons in exhaust gases, which consists essentially of: a porous alumina-magnesia spinel body containing 0.05 to 20% by weight ceria based on the spinel, said porous body having an average pore diameter of 0.01 to 2 microns.
Claim 8
Dependent Claim
39 words
The carrier of claim 5, wherein the porous body contains from 1 to 25% by weight of alumina and magnesia based on the spinel and 0.05 to 20% by weight of ceria based on said spinel, alumina and magnesia.
Claim 9
Dependent Claim
19 words
The carrier of claim 1, wherein the porous body is formed on the surface of a supporting ceramic matrix.
Claim 10
Dependent Claim
28 words
The carrier of claim 7, wherein the supporting ceramic matrix is selected from the group consisting of a sintered α-alumina, a sintered cordierite and a sintered silicon nitride.
Claim 11
Dependent Claim
88 words
A method for preparing the carrier of claim 5, which consists essentially of: mixing a magnesia powder, an alumina powder having an average particle diameter of 0.01 to 2 microns and a powder selected from the group consisting of ceria and a compound convertible to ceria by heating, the ratio of said alumina powder to said magnesia powder ranging from 1.5:1 to 3.5:1 by weight; forming the resulting mixed powder into a desired shape; and calcining the resulting shaped material at a temperature of 1000° to 1600° C.
Claim 12
Dependent Claim
18 words
The method of claim 9, wherein said mixed powdered material is shaped into pellets or a honeycomb structure.
Claim 13
Dependent Claim
19 words
The method of claim 9, wherein said compound convertible to ceria is cerium acetate, cerium carbonate or cerium nitrate.
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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |