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US5017538A Expired / Lapsed US ⏱️ 0.0 years remaining

Catalyst for purifying exhaust gas and a method of producing the same

Assignee: Toyota Motor Corp
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Filing: 1989-04-18
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Granted: 1991-05-21
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Expires: 2009-04-18
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Abstract

Abstract In a catalyst for purifying exhaust gas which comprises zeolite carried on a refractory support and containing copper introduced thereinto by ion exchange, the zeolite has each site of ion exchange located on the surface of its supercage, and a square arrangement of four oxygen atoms around a copper ion. A method of producing the catalyst is also disclosed. Zeolite is dipped in a copper carboxylate solution to cause the ion exchange to take place. It is possible to obtain a catalyst having a high power of removing NO x from exhaust gas if the diameter of the supercage of zeolite is appropriately selected in accordance with the size of HC molecules which the exhaust gas contains.

Inventors

  • 👤 Shinichi Takeshima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 13:39
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/08; B01J29/10; B01J29/14; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 77 words
In the method of producing an exhaust gas purification catalyst comprising a zeolite carried on a refractory support and containing copper introduced thereinto by ion exchange so that said zeolite carries copper ions on the surfaces of its super-cage and has a square arrangement of four oxygen atoms around a copper ion, the improvement which comprises dipping said zeolite in a mixed solution of a copper carboxylate and ammonia to cause said ion exchange to take place.
Claim 2
Dependent Claim 77 words
In the method of producing an exhaust gas purification catalyst comprising a zeolite carried on a refractory support and containing copper introduced thereinto by ion exchange so that said zeolite carries copper ions on the surfaces of its super-cage and has a square arrangement of four oxygen atoms around a copper ion, the improvement which comprises dipping said zeolite in a mixed solution of a copper carboxylate and ammonia to cause said ion exchange to take place.
Claim 3
Dependent Claim 18 words
The method of claim 1, wherein said zeolite is of the type selected from among ZSM-5 and ferrierite.
Claim 4
Dependent Claim 10 words
The method of claim 2, wherein said zeolite is ZSM-5.
Claim 5
Dependent Claim 18 words
The method of claim 1, wherein said support is of a material selected from among ceramics and metals.
Claim 6
Dependent Claim 10 words
The method of claim 1, wherein said support is monolithic.
Claim 7
Dependent Claim 12 words
The method of claim 5, wherein said monolithic support is of cordierite.
Claim 8
Independent Claim 62 words
A method for introducing copper in to a zeolite by ion exchange so that said zeolite raises copper ions on the surfaces of its super-cage and has a square arrangement of four oxygen atoms around a copper ion, which method comprises immersing said zeolite in a mixed solution of a copper carboxylate and ammonia to cause the ion exchange to take place.
Claim 9
Independent Claim 62 words
A method for introducing copper in to a zeolite by ion exchange so that said zeolite raises copper ions on the surfaces of its super-cage and has a square arrangement of four oxygen atoms around a copper ion, which method comprises immersing said zeolite in a mixed solution of a copper carboxylate and ammonia to cause the ion exchange to take place.
Claim 10
Dependent Claim 17 words
The method of claim 7, wherein said zeolite is of the type selected from ZSM-5 and ferrierite.
Claim 11
Dependent Claim 10 words
The method of claim 8, wherein said zeolite is ZSM-5.

References Cited (Backward Citations)

US4331644A Cited
US4297328A Cited
JPS60125250A Cited
JPS6111147A Cited
JPS62291258A Cited
JPS63100919A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-05-20 1994-11-19 1995-05-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-05-20 1998-11-19 1999-05-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-05-20 2002-11-19 2003-05-21 $7700.00 Window Closed / Lapsed

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