US4136059A
Expired / Lapsed
US
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Method for producing highly dispersed catalytic platinum
Assignee: RTX Corp
•
Filing: 1977-12-12
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Granted: 1979-01-23
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Expires: 1997-12-12
Abstract
Abstract Method for the production of highly dispersed electrochemically active platinum particles having an average diameter below about 50 A for use in electrodes for fuel cells. Platinum particles are formed by mixing chloroplatinic acid and sodium dithionite in water to provide a platinum containing colloidal dispersion which may be absorbed on a support material. Hydrogen peroxide can be mixed with the chloroplatinic acid and sodium dithionite to improve the stability of the platinum containing colloidal dispersion.
Inventors
- 👤 Vinod M. Jalan
- 👤 Calvin L. Bushnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:23
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/90; H01M4/92; H01M4/925; B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/42; B01J35/00; B01J35/20; B01J35/23; B01J35/40; B01J35/45; B01J37/00; B01J37/02; B01J37/0201; B01J37/0211; H01M4/926; H01M2004/8678; H01M2004/8684; H01M2004/8689; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
33 words
A method for producing a highly dispersed platinum containing dispersion comprising: mixing in an aqueous medium chloroplatinic acid or a salt thereof and sodium dithionite to provide a dispersion of platinum containing particles.
Claim 2
Independent Claim
33 words
A method for producing a highly dispersed platinum containing dispersion comprising: mixing in an aqueous medium chloroplatinic acid or a salt thereof and sodium dithionite to provide a dispersion of platinum containing particles.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein said particles have an average diameter of less than 50 A.
Claim 4
Dependent Claim
29 words
A method according to claim 2 wherein said chloroplatinic acid or salt thereof and said sodium dithionite are mixed in a weight ratio of about 2:1 to about 1:5.
Claim 5
Dependent Claim
22 words
A method according to claim 3 wherein said method is carried out at a temperature between about 20° C and 80° C.
Claim 6
Dependent Claim
30 words
A method according to claim 4 wherein said chloroplatinic acid or salt thereof is added in an aqueous solution having a concentration range of about 5 to about 100 g/l.
Claim 7
Dependent Claim
27 words
A method according to claim 5 wherein said sodium dithionite is added in an aqueous solution having a concentration range of about 10 to about 100 g/l.
Claim 8
Independent Claim
60 words
A method for producing a highly dispersed platinum containing dispersion comprising: (a) forming an aqueous solution of chloroplatinic acid or a salt thereof; and (b) adding hydrogen peroxide and an aqueous solution of sodium dithionite to solution (a) to form a highly dispersed platinum containing dispersion comprising platinum containing particles having an average diameter of less than about 50 A.
Claim 9
Independent Claim
60 words
A method for producing a highly dispersed platinum containing dispersion comprising: (a) forming an aqueous solution of chloroplatinic acid or a salt thereof; and (b) adding hydrogen peroxide and an aqueous solution of sodium dithionite to solution (a) to form a highly dispersed platinum containing dispersion comprising platinum containing particles having an average diameter of less than about 50 A.
Claim 10
Dependent Claim
29 words
A method according to claim 7 wherein said chloroplatinic acid or salt thereof and said sodium dithionite are mixed in a weight ratio of about 2:1 to about 1:5.
Claim 11
Dependent Claim
27 words
A method according to claim 7 wherein said hydrogen peroxide is added to said (a) solution prior to the addition of said aqueous solution of sodium dithionite.
Claim 12
Dependent Claim
27 words
A method according to claim 7 wherein said aqueous solution of sodium dithionite is added to said (a) solution prior to the addition of said hydrogen peroxide.
Claim 13
Dependent Claim
22 words
A method according to claim 8 wherein said method is carried out at a temperature between about 20° C and 80° C.
Claim 14
Dependent Claim
25 words
A method according to claim 11 wherein said chloroplatinic acid or salt thereof is in a concentration range of about 5 to about 100 g/l.
Claim 15
Dependent Claim
22 words
A method according to claim 12 wherein said sodium dithionite is in a concentration range of about 10 to about 100 g/l.
Claim 16
Independent Claim
75 words
A method for producing a platinum catalyst on a support material for use in fuel cells comprising: (a) mixing an aqueous solution of chloroplatinic acid or a salt thereof and an aqueous solution of sodium dithionite thereby providing a highly dispersed platinum containing dispersion; (b) adsorbing said dispersion on a support material to provide a platinum catalyst on a support material; and (c) separating the platinum catalyst on a support material from the aqueous solution.
Claim 17
Independent Claim
75 words
A method for producing a platinum catalyst on a support material for use in fuel cells comprising: (a) mixing an aqueous solution of chloroplatinic acid or a salt thereof and an aqueous solution of sodium dithionite thereby providing a highly dispersed platinum containing dispersion; (b) adsorbing said dispersion on a support material to provide a platinum catalyst on a support material; and (c) separating the platinum catalyst on a support material from the aqueous solution.
Claim 18
Dependent Claim
28 words
A method according to claim 14 wherein hydrogen peroxide is added to said aqueous solution of chloroplatinic acid or salt thereof prior to the addition of sodium dithionite.
Claim 19
Dependent Claim
28 words
A method according to claim 14 wherein hydrogen peroxide is added to said aqueous solution of chloroplatinic acid or salt thereof subsequent to the addition of sodium dithionite.
Claim 20
Dependent Claim
13 words
A method according to claim 14 wherein said support material is carbon black.
Claim 21
Dependent Claim
31 words
A method according to claim 17 wherein said platinum containing dispersion is adsorbed to said carbon black by mixing an aqueous suspension of said carbon black with said platinum containing dispersion.
Claim 22
Dependent Claim
29 words
A method according to claim 18 wherein said chloroplatinic acid or salt thereof and said sodium dithionite are mixed in a weight ratio of about 2:1 to about 1:5.
Claim 23
Dependent Claim
21 words
A method according to claim 19 wherein said method is carried out at a temperature between 20° C and 80° C.
Claim 24
Dependent Claim
25 words
A method according to claim 20 wherein said chloroplatinic acid or salt thereof is in a concentration range of about 5 to about 100 g/l.
Claim 25
Dependent Claim
22 words
A method according to claim 21 wherein said sodium dithionite is in a concentration range of about 10 to about 100 g/l.
Claim 26
Dependent Claim
57 words
An in situ method of producing a platinum catalyst on a support material comprising: (a) forming a mixture of water and a support material; (b) adding to said (a) mixture chloroplatinic acid and sodium dithionite to provide a platinum catalyst on a support material; and (c) separating the platinum catalyst on the support material from the water.
Claim 27
Dependent Claim
57 words
An in situ method of producing a platinum catalyst on a support material comprising: (a) forming a mixture of water and a support material; (b) adding to said (a) mixture chloroplatinic acid and sodium dithionite to provide a platinum catalyst on a support material; and (c) separating the platinum catalyst on the support material from the water.
Claim 28
Dependent Claim
28 words
A method according to claim 23 wherein hydrogen peroxide is added to said aqueous solution of chloroplatinic acid or salt thereof prior to the addition of sodium dithionite.
Claim 29
Dependent Claim
28 words
A method according to claim 23 wherein hydrogen peroxide is added to said aqueous solution of chloroplatinic acid or salt thereof subsequent to the addition of sodium dithionite.
Claim 30
Dependent Claim
13 words
A method according to claim 23 wherein said support material is carbon black.
Claim 31
Dependent Claim
29 words
A method according to claim 26 wherein said chloroplatinic acid or salt thereof and said sodium dithionite are mixed in a weight ratio of about 2:1 to about 1:5.
Claim 32
Dependent Claim
22 words
A method according to claim 27 wherein said method is carried out at a temperature between about 20° C and 80° C.
Claim 33
Dependent Claim
30 words
A method according to claim 28 wherein said chloroplatinic acid or salt thereof is added in an aqueous solution having a concentration range of about 5 to about 100 g/l.
Claim 34
Dependent Claim
27 words
A method according to claim 29 wherein said sodium diothionite is added in an aqueous solution having a concentration range of about 10 to about 100 g/l.
Claim 35
Dependent Claim
28 words
A method according to claim 14 wherein step (c) comprises filtering the platinum catalyst on support material from the water and drying the platinum catalyst on support material.
Claim 36
Dependent Claim
29 words
A method according to claim 23 wherein step (c) comprises filtering the platinum catalyst on support material from the aqueous solution and drying the platinum catalyst on support material.
References Cited (Backward Citations)
US3956469A
Cited
US4031292A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |