US4024079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing a catalyst for treatment of exhaust gases
Assignee: Nissan Motor Co Ltd
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Filing: 1976-01-29
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Granted: 1977-05-17
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Expires: 1996-01-29
Abstract
Abstract A catalyst is prepared by firstly impregnating a carrier with a solution of a catalytically active metal compound and a sulfur compound and thereafter treating the impregnated carrier in a stream of high temperature steam.
Inventors
- 👤 Toshiki Okuyama
- 👤 Sakae Kawagoshi
- 👤 Tadashi Ikemi
- 👤 Kiyomi Shimonuri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:25
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/0215; B01J37/0219; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/944
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
158 words
A method of preparing a catalyst for treating exhaust gases produced by combustion of hydrocarbon fuel, comprising: coating a substantially chemically inert and substantially catalytically inactive refractory carrier with a liquid containing a sulfur-containing compound of at least one catalytically active metal, said sulfur-containing compound being produced by mixing and reacting in a solvent at least one compound of catalytically active metal and at least one compound selected from the group consisting of ammonium thioglycolate, ammonium thiosulfate and sodium thiosulfate so that the gram atom ratio of the catalytically active metal to the sulfur in the compound thereof is in the range from 1:1 to 1:20; drying said carrier coated with said sulfur-containing compound of at least one catalytically active metal; and heat-treating the dried coated carrier in a stream of steam at a temperature ranging from 300° C to 600° C to decompose the compound and fix the catalytically active metal on the surface of the carrier.
Claim 2
Independent Claim
158 words
A method of preparing a catalyst for treating exhaust gases produced by combustion of hydrocarbon fuel, comprising: coating a substantially chemically inert and substantially catalytically inactive refractory carrier with a liquid containing a sulfur-containing compound of at least one catalytically active metal, said sulfur-containing compound being produced by mixing and reacting in a solvent at least one compound of catalytically active metal and at least one compound selected from the group consisting of ammonium thioglycolate, ammonium thiosulfate and sodium thiosulfate so that the gram atom ratio of the catalytically active metal to the sulfur in the compound thereof is in the range from 1:1 to 1:20; drying said carrier coated with said sulfur-containing compound of at least one catalytically active metal; and heat-treating the dried coated carrier in a stream of steam at a temperature ranging from 300° C to 600° C to decompose the compound and fix the catalytically active metal on the surface of the carrier.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1, in which the solvent in the coating step is water.
Claim 4
Dependent Claim
42 words
A method as claimed in claim 1, in which the catalytically active metal is selected from the group consisting of Pt, Pd, Rh, and Ru. 4. A method as claimed in claim 1, in which the refractory carrier is made of ceramic
Claim 5
Dependent Claim
14 words
material. 5. A method as claimed in claim 4, in which the ceramic material
Claim 6
Dependent Claim
25 words
is selected from the group consisting of alumina and cordierite. 6. A method as claimed in claim 4, in which the refractory carrier is of
Claim 7
Dependent Claim
14 words
spherical type. 7. A method as claimed in claim 4, in which the refractory
Claim 8
Dependent Claim
14 words
carrier is a monolith of honeycomb shape. 8. A method as claimed in claim
Claim 9
Dependent Claim
30 words
2, in which the monolith is coated with activated alumina. 9. A method as claimed in claim 1, in which the gram atom ratio is in the range from 1:2
Claim 10
Dependent Claim
45 words
to 1:6. 10. A method as claimed in claim 1, in which the heat-treating step is carried out by use of the steam in the amount ranging from 1 to 20 times as much as the volume of the carrier when converted to liquid water
Claim 11
Dependent Claim
29 words
at 25° C. 11. A method as claimed in claim 1, in which the heat-treating step is carried out for a time ranging from 20 minutes to 3 hours.
References Cited (Backward Citations)
US3931054A
Cited
US3972829A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |