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US4944273A Expired / Lapsed US ⏱️ 0.0 years remaining

Zeolites as specific adsorbents for NOX and CO

Assignee: Robert Bosch GmbH
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Filing: 1989-02-21
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Granted: 1990-07-31
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Expires: 2009-02-21
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Abstract

Abstract The use of zeolites rich in silicic acids having an Si:Al ratio of 1:1 to 100:1 as specific adsorbents for NO X or CO is proposed. Because of their property of specifically adsorbing NO X or CO, these zeolites, in particular those zeolites doped with such metals as Ca, Co, Ni, Fe, Cu, Ag, Pt or Ru, and having the above mentioned ratio of Si to Al, are especially suitable for the production of specific NO X or CO sensors based on semiconductors. Such sensors can be used as sensors for exhaust gases of automotive vehicles, for example.

Inventors

  • 👤 Detlef Baresel
  • 👤 Peter Scharner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 09:09
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 53 words
A method of selectively adsorbing a nitrogen oxide or carbon monoxide from a gas containing nitrogen oxide or carbon monoxide comprising contacting said gas with a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide.
Claim 2
Independent Claim 53 words
A method of selectively adsorbing a nitrogen oxide or carbon monoxide from a gas containing nitrogen oxide or carbon monoxide comprising contacting said gas with a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide.
Claim 3
Dependent Claim 47 words
The method of claim 1, wherein said zeolite is doped with an effective amount of doping metal selected from the group consisting of Na, Ca, Co, Ni, Fe, Cu, Ag, Pt an Ru to render said zeolite a specific adsorbent for the nitrogen oxide or carbon monoxide.
Claim 4
Dependent Claim 18 words
The method of claim 2, wherein the effective amount is 0.01 to 10 mole % of doping metals.
Claim 5
Dependent Claim 14 words
The method of claim 3, wherein the doping metal is Ca, Ag or Cu.
Claim 6
Dependent Claim 16 words
The method of claim 4, wherein the doping metal is Co, Ni, Fe, Pt or Ru.
Claim 7
Dependent Claim 41 words
The method of claim 1, wherein said zeolite is doped with an effective amount of a doping metal selected from the group consisting of transfer metal cations, to render said zeolite a specific adsorber for the nitrogen oxide or carbon monoxide.
Claim 8
Dependent Claim 17 words
The method of claim 6, wherein the effective amount is 0.01 to 10 mole % of doping.
Claim 9
Dependent Claim 75 words
A sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite.
Claim 10
Dependent Claim 75 words
A sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite.
Claim 11
Dependent Claim 20 words
The sensor of claim 8, wherein said semiconductor is an FET transistor and said zeolite is coated on its gate.
Claim 12
Dependent Claim 48 words
The sensor of claim 9, wherein said zeolite is doped with an effective amount of a doping metal selected from the group consisting of Na, Ca, Co, Ni, Fe, Cu, Ag, Pt and Ru to render said zeolite a specific adsorber for the nitrogen oxide or carbon monoxide.
Claim 13
Dependent Claim 18 words
The sensor of claim 10, wherein the effective amount is 0.01 to 10 mole % of doping metals.
Claim 14
Dependent Claim 14 words
The sensor of claim 11, wherein the doping metal is Ca, Ag or Cu.
Claim 15
Dependent Claim 15 words
The sensor of claim 11, wherein the doping metal is Ni, Fe, Pt or Ru.
Claim 16
Dependent Claim 41 words
The sensor of claim 9, wherein said zeolite is doped with an effective amount of a doping metal selected from the group consisting of transfer metal cations to render said zeolite a specific adsorber for the nitrogen oxide or carbon monoxide.
Claim 17
Dependent Claim 17 words
The sensor of claim 14, wherein the effective amount is 0.01 to 10 mole % of doping.
Claim 18
Dependent Claim 149 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite and wherein said semiconductor is an FET transistor and said zeolite is coated on its gate.
Claim 19
Dependent Claim 149 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite and wherein said semiconductor is an FET transistor and said zeolite is coated on its gate.
Claim 20
Dependent Claim 201 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite, and wherein said semiconductor is an FET transistor and said zeolite is coated on its gate; and said zeolite is doped with an effective amount in the range of 0.01 to 10 mole % of a doping metal selected from the group consisting of Na, Ca, Co, Ni, Fe, Cu, Ag, Pt and Ru to render said zeolite a specific adsorber for the nitrogen oxide or carbon monoxide.
Claim 21
Dependent Claim 201 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite, and wherein said semiconductor is an FET transistor and said zeolite is coated on its gate; and said zeolite is doped with an effective amount in the range of 0.01 to 10 mole % of a doping metal selected from the group consisting of Na, Ca, Co, Ni, Fe, Cu, Ag, Pt and Ru to render said zeolite a specific adsorber for the nitrogen oxide or carbon monoxide.
Claim 22
Dependent Claim 186 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite and wherein said semiconductor is a field effect (FET) transistor and said zeolite is coated on its gate; and said zeolite is doped with an effective amount of a doping metal selected from the group consisting of transfer metal cations to render said zeolite a specific adsorber for the nitrogen or carbon monoxide.
Claim 23
Dependent Claim 186 words
In an internal combustion engine fuel supply control means of the type having a sensor means to generate a signal in proportion to levels of nitrogen oxides or carbon monoxide in exhaust gases from said engine and being operable to control the fuel/air ratio being introduced into the engine for combustion, the improvement wherein said sensor means comprises a sensor specific for a nitrogen oxide or carbon monoxide comprising a semiconductor having a control element; and a zeolite rich in silicic acid with an Si:Al ratio of 1:1 to 100:1, and which is a specific adsorbent for the nitrogen oxide or the carbon monoxide coated on said control element to influence the electrical characteristics of said semiconductor in proportion to the amount of the nitrogen oxide or carbon monoxide adsorbed by said zeolite and wherein said semiconductor is a field effect (FET) transistor and said zeolite is coated on its gate; and said zeolite is doped with an effective amount of a doping metal selected from the group consisting of transfer metal cations to render said zeolite a specific adsorber for the nitrogen or carbon monoxide.

References Cited (Backward Citations)

US3702886A Cited
GB1334243A Cited
US3999122A Cited
US4250345A Cited
US4347732A Cited
US4453151A Cited
US4703646A Cited
US4759210A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-07-30 1994-01-29 1994-07-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-07-30 1998-01-29 1998-07-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-07-30 2002-01-29 2002-07-31 $7700.00 Window Closed / Lapsed

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