Patent US4490219A successfully refreshed from Google Patents.
US4490219A
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Method of manufacture employing electrochemically dispersed platinum catalysts deposited on a substrate
Assignee: International Business Machines Corp
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Filing: 1982-10-07
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Granted: 1984-12-25
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Expires: 2002-10-07
Abstract
Abstract A substrate such as carbon, graphite, or various semiconductors is coated with a "two-dimensional" thin film form of flat isolated crystallites of platinum, palladium or silver to form a catalyst useful in a fuel cell. The method of formation of the catalyst is to place the substrate in an electrolyte such as H 2 PtCl 6 about 1% and one molar sulfuric acid. The potentiostatic pulse plating method is employed. A high potential pulse of very short duration is followed by a low potential of substantial duration. The very high potential nucleates crystals at various randomly distributed nucleation sites such as imperfections in the surface of the substrate. The resulting catalyst has a large surface area of hexagonal crystals about 20 to 40 Angstroms in diameter.
Inventors
- 👤 Perminder S. Bindra
- 👤 David N. Light
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:28
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/90; H01M4/92; H01M4/925; H01M4/926; B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/48; B01J23/50; B01J37/00; B01J37/34; B01J37/348; C; C25; C25B; C25B11/00; C25B11/04; C25B11/051; C25B11/073; C25B11/075; C25B11/081; H01M2300/00; H01M2300/0002; H01M2300/0005; H01M2300/0014; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y10; Y10S; Y10S204/00; Y10S204/09
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
106 words
A method of forming a catalyst comprising plating a substrate plated with thin, dispersed crystallites of a metal in a system including an anode electrode and a cathode electrode, said method comprising, applying a nucleation pulse to said cathode electrode, said nucleation pulse having a potential above the nucleation potential of said metal relative to said anode electrode, and said nucleation pulse having a duration on the order of the microsecond range, and then applying a growth pulse having a potential below said nucleation potential for a longer period of time an order of magnitude longer than said nucleation pulse, to add mass to said crystallites.
Claim 2
Independent Claim
106 words
A method of forming a catalyst comprising plating a substrate plated with thin, dispersed crystallites of a metal in a system including an anode electrode and a cathode electrode, said method comprising, applying a nucleation pulse to said cathode electrode, said nucleation pulse having a potential above the nucleation potential of said metal relative to said anode electrode, and said nucleation pulse having a duration on the order of the microsecond range, and then applying a growth pulse having a potential below said nucleation potential for a longer period of time an order of magnitude longer than said nucleation pulse, to add mass to said crystallites.
Claim 3
Independent Claim
79 words
A method of deposition of a plurality of crystals of a catalyst on a substrate by applying a nucleation plating potential initially, said nucleation potential being above the nucleation potential of said metal, application of said nucleation potential being followed by a sharply lower potential, below said nucleation potential of said metal for a longer period of time an order or magnitude longer than said nucleation pulse to form flat isolated crystallites of said catalyst metal on said substrate.
Claim 4
Independent Claim
79 words
A method of deposition of a plurality of crystals of a catalyst on a substrate by applying a nucleation plating potential initially, said nucleation potential being above the nucleation potential of said metal, application of said nucleation potential being followed by a sharply lower potential, below said nucleation potential of said metal for a longer period of time an order or magnitude longer than said nucleation pulse to form flat isolated crystallites of said catalyst metal on said substrate.
Claim 5
Dependent Claim
83 words
An article of manufacture comprising a catalyst formed by plating a substrate with thin, dispersed crystallites of a metal by the steps of applying a nucleation pulse to a cathode electrode, said nucleation pulse having a potential above the nucleation potential of said metal relative to said anode electrode, and then applying a growth pulse having a potential below said nucleation potential for a longer period of time an order of magnitude longer than said nucleation pulse, to add mass to said crystallites.
Claim 6
Dependent Claim
83 words
An article of manufacture comprising a catalyst formed by plating a substrate with thin, dispersed crystallites of a metal by the steps of applying a nucleation pulse to a cathode electrode, said nucleation pulse having a potential above the nucleation potential of said metal relative to said anode electrode, and then applying a growth pulse having a potential below said nucleation potential for a longer period of time an order of magnitude longer than said nucleation pulse, to add mass to said crystallites.
Claim 7
Dependent Claim
91 words
An article of manufacture comprising a deposit of a plurality of crystals of a catalyst on a substrate, said crystals having been deposited by applying a nucleation plating potential initially, said nucleation potential being above the nucleation potential of said metal, application of said nucleation potential being followed by a plating potential comprising a sharply lower potential, below said nucleation potential of said metal, for a longer period of time an order of magnitude longer than said nucleation pulse, to form flat isolated crystallites of said catalyst metal on said substrate.
Claim 8
Dependent Claim
91 words
An article of manufacture comprising a deposit of a plurality of crystals of a catalyst on a substrate, said crystals having been deposited by applying a nucleation plating potential initially, said nucleation potential being above the nucleation potential of said metal, application of said nucleation potential being followed by a plating potential comprising a sharply lower potential, below said nucleation potential of said metal, for a longer period of time an order of magnitude longer than said nucleation pulse, to form flat isolated crystallites of said catalyst metal on said substrate.
Claim 9
Independent Claim
144 words
A method of forming a catalyst comprising plating a substrate plated with thin, dispersed crystallites of platinum comprising, applying a nucleation pulse to a cathode electrode said crystals having been deposited by applying a plating potential of less than or equal to about -0.3 V vs SCE, said nucleation pulse having a duration on the order of a few microseconds, said nucleation pulse having a potential above the nucleation potential of said platinum relative to the anode electrode and then applying a growth pulse having a potential below said nucleation potential said growth pulse having a potential greater than or equal to about 0.1 V vs SCE for a longer period of time to add mass to said crystallites, said growth pulse having a duration of about one to several milliseconds to form flat, isolated tabular crystallites of said platinum catalyst on said substrate.
Claim 10
Independent Claim
144 words
A method of forming a catalyst comprising plating a substrate plated with thin, dispersed crystallites of platinum comprising, applying a nucleation pulse to a cathode electrode said crystals having been deposited by applying a plating potential of less than or equal to about -0.3 V vs SCE, said nucleation pulse having a duration on the order of a few microseconds, said nucleation pulse having a potential above the nucleation potential of said platinum relative to the anode electrode and then applying a growth pulse having a potential below said nucleation potential said growth pulse having a potential greater than or equal to about 0.1 V vs SCE for a longer period of time to add mass to said crystallites, said growth pulse having a duration of about one to several milliseconds to form flat, isolated tabular crystallites of said platinum catalyst on said substrate.
Claim 11
Independent Claim
117 words
A method for deposition of a plurality of crystals of a catalyst on a substrate by applying a plating potential, said potential being above the nucleation potential of said platinum initially said nucleation potential being less than or equal to about -0.3 V vs SCE, said nucleation potential comprising a pulse having a duration on the order of a few microseconds, followed by application of a plating potential pulse less than said nucleation potential of said platinum said plating potential being greater than or equal to about +0.1 V vs SCE said plating potential pulse having a duration of about one to several milliseconds to form flat, isolated tabular crystallites of said platinum catalyst on said substrate.
Claim 12
Independent Claim
117 words
A method for deposition of a plurality of crystals of a catalyst on a substrate by applying a plating potential, said potential being above the nucleation potential of said platinum initially said nucleation potential being less than or equal to about -0.3 V vs SCE, said nucleation potential comprising a pulse having a duration on the order of a few microseconds, followed by application of a plating potential pulse less than said nucleation potential of said platinum said plating potential being greater than or equal to about +0.1 V vs SCE said plating potential pulse having a duration of about one to several milliseconds to form flat, isolated tabular crystallites of said platinum catalyst on said substrate.
Claim 13
Dependent Claim
133 words
An article of manufacture comprising a catalyst formed by plating a substrate with thin, dispersed crystallites of platinum by the steps of applying a nucleation pulse to a cathode electrode said nucleation pulse having a potential above the nucleation potential of said platinum relative to the anode electrode, said nucleation pulse having a duration on the order of a few microseconds, said nucleation potential being less than or equal to about -0.3 V vs SCE, and then applying a growth pulse having a potential below said nucleation potential said growth pulse having a potential greater than or equal to about +0.1 V vs SCE, said growth pulse being applied for a longer period of time with a duration on the order of about one to several milliseconds to add mass to said crystallites.
Claim 14
Dependent Claim
133 words
An article of manufacture comprising a catalyst formed by plating a substrate with thin, dispersed crystallites of platinum by the steps of applying a nucleation pulse to a cathode electrode said nucleation pulse having a potential above the nucleation potential of said platinum relative to the anode electrode, said nucleation pulse having a duration on the order of a few microseconds, said nucleation potential being less than or equal to about -0.3 V vs SCE, and then applying a growth pulse having a potential below said nucleation potential said growth pulse having a potential greater than or equal to about +0.1 V vs SCE, said growth pulse being applied for a longer period of time with a duration on the order of about one to several milliseconds to add mass to said crystallites.
Claim 15
Dependent Claim
130 words
An article of manufacture comprising a deposit of a plurality of hexagonal crystals of a platinum catalyst on a substrate, said crystals having been deposited by applying a nucleation pulse with a voltage of about -0.3 V vs SCE or less said nucleation pulse having a duration on the order of a few microseconds, said potential being above the nucleation potential of said platinum initially, followed by a plating growth pulse of a sharply lower potential less than said nucleation potential of said platinum of greater than or equal to about +0.1 V vs. SCE said growth pulse lasting for a period with a duration on the order of about one to several milliseconds, whereby the deposits comprise flat, tabular, hexagonal, isolated crystallites of said platinum catalyst on said substrate.
Claim 16
Dependent Claim
130 words
An article of manufacture comprising a deposit of a plurality of hexagonal crystals of a platinum catalyst on a substrate, said crystals having been deposited by applying a nucleation pulse with a voltage of about -0.3 V vs SCE or less said nucleation pulse having a duration on the order of a few microseconds, said potential being above the nucleation potential of said platinum initially, followed by a plating growth pulse of a sharply lower potential less than said nucleation potential of said platinum of greater than or equal to about +0.1 V vs. SCE said growth pulse lasting for a period with a duration on the order of about one to several milliseconds, whereby the deposits comprise flat, tabular, hexagonal, isolated crystallites of said platinum catalyst on said substrate.
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 |