US5141906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for purifying exhaust gas
Assignee: Toyota Motor Corp
•
Filing: 1991-06-28
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Granted: 1992-08-25
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Expires: 2011-06-28
Abstract
Abstract A catalyst for purifying an exhaust gas comprising a zeolite catalyst ion-exchanged with a transition metal, which is heat-treated in a gas stream containing a sulfur oxide, optionally followed by washing with a glycol.
Inventors
- 👤 Shinichi Takeshima
- 👤 Toshiaki Tanaka
- 👤 Kiyohiko Oishi
- 👤 Tokuta Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:24
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/064; B01J29/072; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
53 words
A catalyst for purifying an exhaust gas, comprising a zeolite catalyst ion exchanged with a transition metal selected from the group consisting of Cu, Co, Cr, Ni, Fe, Mg and Mn, said ion-exchanged zeolite catalyst being heat-treated at a temperature of 500° to 700° C. in a gas stream containing a sulfur compound.
Claim 2
Dependent Claim
53 words
A catalyst for purifying an exhaust gas, comprising a zeolite catalyst ion exchanged with a transition metal selected from the group consisting of Cu, Co, Cr, Ni, Fe, Mg and Mn, said ion-exchanged zeolite catalyst being heat-treated at a temperature of 500° to 700° C. in a gas stream containing a sulfur compound.
Claim 3
Dependent Claim
19 words
A catalyst as claimed in claim 1, wherein said zeolite has a pore size of 5° to 10° Å.
Claim 4
Dependent Claim
25 words
A catalyst as claimed in claim 1, wherein the transition metal is at least one component selected from the group consisting of Cu and Co.
Claim 5
Dependent Claim
14 words
A catalyst as claimed in claim 1, wherein the sulfur compound is hydrogen sulfide.
Claim 6
Dependent Claim
40 words
A catalyst for purifying an exhaust gas, comprising a zeolite catalyst ion exchanged with a transition metal, said ion-exchanged zeolite catalyst being heat-treated in a gas stream containing a sulfur compound, wherein the heat-treated catalyst is washed with a glycol.
Claim 7
Dependent Claim
40 words
A catalyst for purifying an exhaust gas, comprising a zeolite catalyst ion exchanged with a transition metal, said ion-exchanged zeolite catalyst being heat-treated in a gas stream containing a sulfur compound, wherein the heat-treated catalyst is washed with a glycol.
Claim 8
Dependent Claim
13 words
A catalyst as claimed in claim 5, wherein the glycol is ethylene glycol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-25 | 1996-02-24 | 1996-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-25 | 2000-02-24 | 2000-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-25 | 2004-02-24 | 2004-08-25 | $7700.00 | Window Closed / Lapsed |