US3990957A
Expired / Lapsed
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Method of electrolysis
Assignee: PPG Industries Inc
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Filing: 1975-11-17
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Granted: 1976-11-09
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Expires: 1995-11-17
Abstract
Abstract Disclosed is a method of electrolyzing an aqueous alkali metal chloride, which method comprises passing an electrolytic current from an anode of an electrolytic cell through an alkali metal chloride electrolyte to a cathode of the cell, evolving chlorine at the anode and hydrogen at the cathode. The method is characterized by the use of a cathode having a layer of an oxy-compound of a platinum group metal and an alkaline earth metal on an electroconductive cathode substrate.
Inventors
- 👤 Howard H. Hoekje
- 👤 Harlan B. Johnson
- 👤 Ronald D. Chamberlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:35
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C25B11/00; C25B11/04; C25B11/051; C25B11/073; C25B11/091; C25B11/093
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
68 words
In a method of electrolyzing aqueous alkali metal chloride comprising passing an electrolytic current from an anode of an electrolytic cell through the alkali metal chloride electrolyte to a cathode, evolving chlorine at the anode, and evolving hydrogen at the cathode, the improvement wherein said cathode comprises a layer of an oxy-compound of a perovskite forming platinum group metal and an alkaline earth metal on an electroconductive substrate.
Claim 2
Dependent Claim
68 words
In a method of electrolyzing aqueous alkali metal chloride comprising passing an electrolytic current from an anode of an electrolytic cell through the alkali metal chloride electrolyte to a cathode, evolving chlorine at the anode, and evolving hydrogen at the cathode, the improvement wherein said cathode comprises a layer of an oxy-compound of a perovskite forming platinum group metal and an alkaline earth metal on an electroconductive substrate.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the perovskite forming platinum group metal is chosen from the group consisting of osmium, ruthenium, and mixtures thereof.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein the alkaline earth metal is chosen from the group consisting of magnesium, calcium, strontium, barium, and mixtures thereof.
Claim 5
Dependent Claim
34 words
The method of claim 1 wherein the oxy-compound is chosen from the group consisting of magnesium ruthenate, magnesium ruthenite, calcium ruthenate, calcium ruthenite, strontium ruthenate, strontium ruthenite, barium ruthenate, barium ruthenite, and mixtures thereof.
Claim 6
Dependent Claim
53 words
The method of claim 4 wherein the oxy-compound of the perovskite forming platinum group metal and the alkaline earth metal is formed in situ on the surface of the cathode, and the cathode substrate has a layer of a material that is resistant to oxidation during the in situ formation of the oxy-compound.
Claim 7
Dependent Claim
32 words
The method of claim 5 wherein the cathode substrate has a layer of nickel beneath the layer of the oxy-compound of the perovskite forming platinum group metal and the alkaline earth metal.
Claim 8
Dependent Claim
13 words
The method of claim 1 wherein the alkali metal chloride is sodium chloride.
Claim 9
Dependent Claim
94 words
In a method of electrolyzing aqueous alkali metal chloride comprising passing an electrolytic current from an anode of an electrolytic cell through the alkali metal chloride electrolyte to an iron cathode, evolving chlorine at the anode, and evolving hydrogen at the iron cathode at a hydrogen evolution overvoltage above about 0.25 volt at a current density of 100 amperes per square foot, the improvement comprises reducing the hydrogen evolution overvoltage of the cathode by providing a layer of an oxy-compound of a platinum group metal and an alkaline earth metal on the iron cathode.
Claim 10
Dependent Claim
94 words
In a method of electrolyzing aqueous alkali metal chloride comprising passing an electrolytic current from an anode of an electrolytic cell through the alkali metal chloride electrolyte to an iron cathode, evolving chlorine at the anode, and evolving hydrogen at the iron cathode at a hydrogen evolution overvoltage above about 0.25 volt at a current density of 100 amperes per square foot, the improvement comprises reducing the hydrogen evolution overvoltage of the cathode by providing a layer of an oxy-compound of a platinum group metal and an alkaline earth metal on the iron cathode.
Claim 11
Dependent Claim
28 words
The method of claim 8 wherein the platinum group metal is a perovskite forming platinum group metal chosen from the group consisting of osmium, ruthenium, and mixtures thereof.
Claim 12
Dependent Claim
23 words
The method of claim 8 wherein the alkaline earth metal is chosen from the group consisting of calcium, strontium, barium, and mixtures thereof.
Claim 13
Dependent Claim
30 words
The method of claim 8 wherein the oxy-compound is chosen from the group consisting of calcium ruthenate, calcium ruthenite, strontium ruthenate, strontium ruthenite, barium ruthenate, barium ruthenite, and mixtures thereof.
Claim 14
Dependent Claim
53 words
The method of claim 11 wherein the oxy-compound of the perovskite forming platinum group metal and the alkaline earth metal is formed in situ on the surface of the cathode, and the cathode substrate has a layer of a material that is resistant to oxidation during the in situ formation of the oxy-compound.
Claim 15
Dependent Claim
32 words
The method of claim 12 wherein the cathode substrate has a layer of nickel beneath the layer of the oxy-compound of the perovskite forming platinum group metal and the alkaline earth metal.
Claim 16
Dependent Claim
13 words
The method of claim 8 wherein the alkali metal chloride is sodium chloride.
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) | 1979-11-09 | 1980-05-10 | 1980-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-09 | 1984-05-10 | 1984-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-09 | 1988-05-10 | 1988-11-09 | $7700.00 | Window Closed / Lapsed |