US4120821A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for conversion of engine exhaust gas
Assignee: Nissan Motor Co Ltd
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Filing: 1976-08-12
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Granted: 1978-10-17
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Expires: 1996-08-12
Abstract
Abstract A catalyst, which has high and long-lasting activity on both the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides particularly when an internal combustion engine is operated at an air-fuel ratio around a stoichiometric ratio, consists of a carrier of active alumina, 0.05-0.2 Wt% platinum, 0.0015-0.045 Wt% rhodium and 0.002-5 Wt% boron.
Inventors
- 👤 Akio Iizuka
- 👤 Michiichi Taguchi
- 👤 Muneyuki Kubo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:12
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/46; B01J23/464; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
95 words
A catalyst for simultaneous oxidation of hydrocarbons and carbon monoxide and reduction of nitrogen oxides in exhaust gas of an internal combustion engine, consisting essentially of a carrier which is made of active alumina at least in a surface portion thereof, 0.05-0.2 Wt% of the carrier of platinum, 0.0015-0.045 Wt% of the carrier of rhodium and 0.002-5 Wt% of the carrier of boron said catalyst being produced by impregnating said carrier with three thermally decomposable compounds of, respectively, platinum, rhodium and boron and then baking the impregnated carrier at temperatures not higher than 650° C.
Claim 2
Dependent Claim
95 words
A catalyst for simultaneous oxidation of hydrocarbons and carbon monoxide and reduction of nitrogen oxides in exhaust gas of an internal combustion engine, consisting essentially of a carrier which is made of active alumina at least in a surface portion thereof, 0.05-0.2 Wt% of the carrier of platinum, 0.0015-0.045 Wt% of the carrier of rhodium and 0.002-5 Wt% of the carrier of boron said catalyst being produced by impregnating said carrier with three thermally decomposable compounds of, respectively, platinum, rhodium and boron and then baking the impregnated carrier at temperatures not higher than 650° C.
Claim 3
Dependent Claim
24 words
A catalyst as claimed in claim 1, wherein the amount of boron is in the range from 0.002 to 0.5 Wt% of the carrier.
Claim 4
Dependent Claim
41 words
The catalyst as claimed in claim 1, wherein said three decomposable compounds are chloroplatinic acid, rhodium trichloride and boric acid, and said baking of the impregnated carrier being performed in a stream of hydrogen at temperatures between 150° and 500° C.
Claim 5
Dependent Claim
24 words
A catalyst as claimed in claim 3, wherein the amount of boron is in the range from 0.002 to 0.5 Wt% of said catalyst.
Claim 6
Independent Claim
82 words
A method for the preparation of an anti-pollution catalyst for internal combustion engine exhaust gases which comprises the steps of: (a) impregnating an active alumina carrier with a thermally decomposable compound of each of platinum, rhodium and boron in amounts of each to provide upon decomposition, based upon the weight of carrier of 0.05-0.2 wt % of platinum, 0.0015- 0.045 wt % of rhodium and 0.002-5 wt % of boron; (b) baking the impregnated carrier at temperatures not higher than 650° C.
Claim 7
Independent Claim
82 words
A method for the preparation of an anti-pollution catalyst for internal combustion engine exhaust gases which comprises the steps of: (a) impregnating an active alumina carrier with a thermally decomposable compound of each of platinum, rhodium and boron in amounts of each to provide upon decomposition, based upon the weight of carrier of 0.05-0.2 wt % of platinum, 0.0015- 0.045 wt % of rhodium and 0.002-5 wt % of boron; (b) baking the impregnated carrier at temperatures not higher than 650° C.
Claim 8
Dependent Claim
27 words
The method according to claim 5 wherein said baking of the impregnated carrier is performed in a stream of hydrogen at temperatures between 150° and 500° C.
Claim 9
Dependent Claim
41 words
The catalyst as claimed in claim 1, wherein said three decomposable compounds are chloroplatinic acid, rhodium tricholoride and boric acid, and said baking of the impregnated carrier being performed in a stream of air at temperatures between 500° and 650° C.
Claim 10
Dependent Claim
24 words
A catalyst as claimed in claim 7, wherein the amount of boron is in the range from 0.002 to 0.5 Wt% of said catalyst.
Claim 11
Dependent Claim
42 words
The catalyst as claimed in claim 1, wherein said three decomposable compounds are chloroplatinic acid, rhodium tricholoride and boric acid, and said baking of the impregnated carrier being performed in a stream of 100% steam at temperatures between 400° and 550° C.
Claim 12
Dependent Claim
24 words
A catalyst as claimed in claim 9, wherein the amount of boron is in the range from 0.002 to 0.5 Wt% of said catalyst.
Claim 13
Dependent Claim
47 words
The catalyst as claimed in claim 1, wherein said three decomposable compounds are chloroplatinic acid, rhodium tricholoride and boric acid, and said baking of the impregnated carrier being performed in a stream of a 50/50 mixture of air and steam at temperatures between 450° and 600° C.
Claim 14
Dependent Claim
24 words
A catalyst as claimed in claim 11, wherein the amount of boron is in the range from 0.002 to 0.5 Wt% of said catalyst.
Claim 15
Dependent Claim
27 words
The method according to claim 5 wherein said baking of the impregnated carrier is performed in a stream of air at temperatures between 500° and 650° C.
Claim 16
Dependent Claim
28 words
The method according to claim 5 wherein said baking of the impregnated carrier is performed in a stream of 100% steam at temperatures between 400° and 550° C.
Claim 17
Dependent Claim
33 words
The method according to claim 5 wherein said baking of the impregnated carrier is performed in a stream of a 50/50 mixture of air and steam at temperatures between 450° and 600° C.
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) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |