US4735930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst for the reduction of oxides of nitrogen
Assignee: Saint Gobain Abrasives Inc
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Filing: 1986-02-18
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Granted: 1988-04-05
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Expires: 2006-02-18
Abstract
Abstract A catalyst for the selective reduction of nitrogen oxides to nitrogen in the presence of ammonia in the form of composite bodies formed from a mixture of zirconia (5 to 50% by weight), a zeolite (50 to 90%), a bond material (0 to 30%), and, optionally, a promoter selected from oxides of vanadium and copper in the amount of at least 0.1% by weight.
Inventors
- 👤 William H. Gerdes
- 👤 Charles Lim
- 👤 Thomas Szymanski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:46
CPC Classifications
B; B01; B01J; B01J20/00; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; B01J29/00; B01J29/04; B01J29/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
74 words
A catalyst for the selective reduction of NOx to nitrogen in the presence of ammonia, said catalyst being a shaped coformed mixture of 5 to 50% by weight of zirconia starting material having a surface area of at least 10, preferably greater than 50 square meters per gram and containing at least 50 to 90% of one or more zeolites in the hydrogen or ammonium form and up to 30% of a bonding agent.
Claim 2
Dependent Claim
74 words
A catalyst for the selective reduction of NOx to nitrogen in the presence of ammonia, said catalyst being a shaped coformed mixture of 5 to 50% by weight of zirconia starting material having a surface area of at least 10, preferably greater than 50 square meters per gram and containing at least 50 to 90% of one or more zeolites in the hydrogen or ammonium form and up to 30% of a bonding agent.
Claim 3
Dependent Claim
27 words
A catalyst as in claim 1 containing at least 0.1% by weight of a promoter selected from the group consisting of oxides of vanadium and of copper.
Claim 4
Dependent Claim
16 words
A catalyst as in claim 1 in which said zeolite contains a major portion of clinoptilolite.
Claim 5
Dependent Claim
12 words
A catalyst as in claim 1 in which said zeolite is clinoptilolite.
Claim 6
Dependent Claim
19 words
A catalyst as in claim 1 in which the zirconia is derived from the hydrolysis of a zirconyl salt.
Claim 7
Dependent Claim
25 words
A catalyst as in claim 1 in which said zirconia is derived from the hydrolysis of one or more zirconium salts to ZrO 2 .
Claim 8
Dependent Claim
21 words
A catalyst as in claim 1 in the form of rings, spheres, cross partition rings, stars, saddles, aggregates, honeycombs, or pellets.
Claim 9
Dependent Claim
27 words
A catalyst as in claim 4 containing at least 0.1% by elemental weight of a promoter selected from the group of oxides of vanadium or of copper.
Claim 10
Dependent Claim
20 words
A catalyst as in claim 1 in which the active catalyst composition is coated onto a metal or ceramic support.
References Cited (Backward Citations)
US3345135A
Cited
US3346328A
Cited
US3615166A
Cited
US4085193A
Cited
US3895094A
Cited
US4220632A
Cited
US4473535A
Cited
GB2039863A
Cited
SU831166A1
Cited
JPS5987044A
Cited
US4663300A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |