US4490482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a catalyst for oxidizing carbon monoxide
Assignee: Department of National Defence
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Filing: 1983-10-25
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Granted: 1984-12-25
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Expires: 2003-10-25
Abstract
Abstract A catalyst for recombining oxygen and carbon monoxide in a sealed CO 2 laser includes a stannic oxide base and a coating of at least one metal selected from the group consisting of platinum, palladium, ruthenium, gold and rhodium. The stannic oxide base is produced by preparing a mixture of a stannous salt such as stannous chloride and stannic acid, adding a base to the mixture to produce a mixture of stannic and stannous hydroxide, and adding an oxidizing agent such as hydrogen peroxide to the hydroxide mixture to yield a precipitate of stannic oxide. The stannic oxide is mixed with a catalyst metal salt such as the chloride of one of the metals mentioned hereinbefore, and a reducing agent, e.g. formic acid is added to the oxide and salt mixture to produce the salt, whereby the catalyst metal is deposited on the stannic oxide.
Inventors
- 👤 Pierre Mathieu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:31
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/62; B01J23/622; B01J23/626; H; H01; H01S; H01S3/00; H01S3/02; H01S3/03; H01S3/036
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A method of producing a catalyst of the type including a stannic oxide base and a coating of at least one catalyst metal selected from the group consisting of platinum, palladium, ruthenium, gold and rhodium, said method comprising the steps of: (a) preparing a mixture of a stannous salt and stannic acid; (b) adding a base to said mixture to produce a mixture of stannic and stannous hydroxide; (c) adding an oxidizing agent to said hydroxide mixture to yield a stannic oxide precipitate; (d) mixing said stannic oxide with an aqueous solution of a salt of at least one said catalyst metal; (e) adding a reducing agent to the oxide and salt mixture to reduce the salt, whereby the catalyst metal is deposited on the stannic oxide; and (f) drying the resulting metal coated stannic oxide.
Claim 2
Independent Claim
136 words
A method of producing a catalyst of the type including a stannic oxide base and a coating of at least one catalyst metal selected from the group consisting of platinum, palladium, ruthenium, gold and rhodium, said method comprising the steps of: (a) preparing a mixture of a stannous salt and stannic acid; (b) adding a base to said mixture to produce a mixture of stannic and stannous hydroxide; (c) adding an oxidizing agent to said hydroxide mixture to yield a stannic oxide precipitate; (d) mixing said stannic oxide with an aqueous solution of a salt of at least one said catalyst metal; (e) adding a reducing agent to the oxide and salt mixture to reduce the salt, whereby the catalyst metal is deposited on the stannic oxide; and (f) drying the resulting metal coated stannic oxide.
Claim 3
Dependent Claim
33 words
A method according to claim 1, wherein said stannic acid is prepared by adding a base to a stannic salt to produce a stannic hydroxide gel, and reacting said gel with hydrochloric acid.
Claim 4
Dependent Claim
48 words
A method according to claim 2, wherein ammonium hydroxide is added to an aqueous solution of stannic chloride to precipitate a stannic hydroxide gel; an aqueous solution of hydrochloric acid is added to the gel; and the resulting mixture is boiled until all of the hydroxide is dissolved.
Claim 5
Dependent Claim
25 words
A method according to claim 1, wherein said stannous salt is stannous chloride and said catalyst metal salt is a chloride of the catalyst metal.
Claim 6
Dependent Claim
12 words
A method according to claim 4, wherein said base is ammonium hydroxide.
Claim 7
Dependent Claim
13 words
A method according to claim 5, wherein said oxidizing agent is hydrogen peroxide.
Claim 8
Dependent Claim
14 words
A method according to claim 6, wherein said catalyst metal salt is platinum chloride.
Claim 9
Independent Claim
13 words
A method according to claum 7, wherein said reducing agent is formic acid.
Claim 10
Independent Claim
13 words
A method according to claum 7, wherein said reducing agent is formic acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |