Patent DE244386C successfully refreshed from Google Patents.
Patent US5298280A successfully refreshed from Google Patents.
US5298280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing an electrode by electroless deposition
Assignee: Olin Corp
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Filing: 1991-08-01
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Granted: 1994-03-29
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Expires: 2011-08-01
Abstract
Abstract A process for fabricating a porous, high surface area electrode and the use of that electrode in an electrolytic cell for manufacturing chlorine-free chlorine dioxide from dilute alkali metal chlorite solutions in a single step is disclosed. The electrolytic cell uses a porous flow-through anode and a cathode separated by a suitable separator.
Inventors
- 👤 Jerry J. Kaczur
- 👤 David W. Cawlfield
- 👤 Julian F. Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:15
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/24; C25B1/26; C25B9/00; C25B9/17; C25B9/19
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
206 words
A method of fabricating a porous, high surface area electrode used as an anode comprising the steps of: (a) removing any oxide film coating from a valve metal substrate wherein said substrate has a porous, geometrically structured surface area; (b) forming a plating solution comprising a solution of a precious metal salt and a reducing agent wherein the molar ratio of said reducing agent to said precious metal salt is from about 0.1:1 to about 500:1 and the pH of said plating solution is from about 0.025 to about 5; (c) forming an electrocatalytic precious metal-plated electrode substrate having a porous, geometrically structured surface area by electrolessly plating said precious metal onto the oxide-free surfaces of said electrode substrate for a time to cover about 10 to about 95% of the surface area of said electrode substrate with said electrocatalytic precious metal; said electrocatalytic precious metal coating having grain crystals distributed on the surface of said substrate and said plated electrode substrate having a fill density of less than 60% and a surface area to volume ratio of greater than 10 cm 2 /cm 3 ; (d) removing said plated electrode substrate from said plating solution; and (e) subjecting said plated electrode to rinsing and drying.
Claim 2
Independent Claim
206 words
A method of fabricating a porous, high surface area electrode used as an anode comprising the steps of: (a) removing any oxide film coating from a valve metal substrate wherein said substrate has a porous, geometrically structured surface area; (b) forming a plating solution comprising a solution of a precious metal salt and a reducing agent wherein the molar ratio of said reducing agent to said precious metal salt is from about 0.1:1 to about 500:1 and the pH of said plating solution is from about 0.025 to about 5; (c) forming an electrocatalytic precious metal-plated electrode substrate having a porous, geometrically structured surface area by electrolessly plating said precious metal onto the oxide-free surfaces of said electrode substrate for a time to cover about 10 to about 95% of the surface area of said electrode substrate with said electrocatalytic precious metal; said electrocatalytic precious metal coating having grain crystals distributed on the surface of said substrate and said plated electrode substrate having a fill density of less than 60% and a surface area to volume ratio of greater than 10 cm 2 /cm 3 ; (d) removing said plated electrode substrate from said plating solution; and (e) subjecting said plated electrode to rinsing and drying.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said valve metal is selected from the group consisting of titanium, niobium, zirconium, and tantalum.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said valve metal is titanium.
Claim 5
Dependent Claim
44 words
The method of claim 1 wherein said plating solution comprises a mixture of a solution of chloroplatinic acid with a solution of a reducing agent selected from the group consisting of hypophosphites, formaldehyde, hydrazine, formic acid, borohydride, amine boranes, derivatives thereof, and salts thereof.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein said valve metal oxide film coating is removed in step (a) by means of an acid etch.
Claim 7
Dependent Claim
29 words
The method of claim 5 wherein the acid used in said acid etch is selected from the group consisting of hydrochloric acid, sulfuric acid, oxalic acid, or hydrofluoric acid.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein said plating solution additionally contains a wetting agent.
Claim 9
Dependent Claim
14 words
The method of claim 7 wherein said wetting agent is a sulfonic acid salt.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein said plating solution additional contains a complexing agent.
Claim 11
Dependent Claim
15 words
The method of claim 9 wherein said complexing agent is ethylenediaminetetraacetic acid salts or amines.
Claim 12
Dependent Claim
24 words
The method of claim 1 wherein said plating solution contains a precious metal content of between about 0.01 to about 100 grams per liter.
Claim 13
Dependent Claim
19 words
The method of claim 1 wherein the pH of said plating solution is from about 0.05 to about 4.0.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein step (c) is carried out at a temperature from about 5° C. to 150° C.
Claim 15
Dependent Claim
24 words
The method of claim 1 wherein about 15% to about 90% of surface area of said substrate is plated with said electrocatalytic precious metal.
Claim 16
Dependent Claim
29 words
The method of claim 1 wherein plated electrode after removing step (d) and before rinsing step (e) is neutralized of any acidity by immersion into a dilute alkali bath.
Claim 17
Dependent Claim
15 words
The method of claim 1 wherein said rinsing step is carried out with deionized water.
Claim 18
Dependent Claim
47 words
The method of claim 1 wherein plated electrode is treated to enhance the adhesion of the precious metal coating to the electrode substrate, said treatment selected from the group consisting of heat annealing under a vacuum, alloying under a vacuum, chemical treatments, and a second plating procedure.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-03-28 | 1997-09-27 | 1998-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-28 | 2001-09-27 | 2002-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-28 | 2005-09-27 | 2006-03-29 | $7700.00 | Window Closed / Lapsed |