US4572770A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation and use of electrodes in the electrolysis of alkali halides
Assignee: Dow Chemical Co
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Filing: 1984-06-27
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Granted: 1986-02-25
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Expires: 2004-06-27
Abstract
Abstract A substrate is coated with a solution of metal oxide precursor compounds and an etchant for etching the substrate, the metal oxide precursor compounds are thermally concentrated by removing volatiles therefrom, and the so-concentrated metal oxides precursors are thermally oxidized in-situ on the substrate. The so-formed compositions are useful, e.g., as electrode material in electrochemical apparatuses and processes.
Inventors
- 👤 R. Neal Beaver
- 👤 Carl E. Byrd
- 👤 Lloyd E. Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:59
CPC Classifications
C; C25; C25B; C25B11/00; C25B11/04; C25B11/051; C25B11/073; C25B11/091; C25B11/093
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
170 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a cation exchange membrane to produce an aqueous solution of sodium hydroxide in the catholyte compartment, and chlorine in the anolyte compartment, wherein the cathode of said process is a low hydrogen overvoltage cathode made by applying to an electroconductive substrate a coating solution of nickel oxide and platinum group metal oxide precursor compound(s) and an etchant capable of etching the surface of the substrate and/or any previously applied coating, heating to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previous coating to be concentrated and recoated on the substrate or previously applied coating, and further heating, in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values, thereby obtaining on said substrate an electrocatalytically-active heterogeneous coating of a mixture of the metal oxides.
Claim 2
Dependent Claim
170 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a cation exchange membrane to produce an aqueous solution of sodium hydroxide in the catholyte compartment, and chlorine in the anolyte compartment, wherein the cathode of said process is a low hydrogen overvoltage cathode made by applying to an electroconductive substrate a coating solution of nickel oxide and platinum group metal oxide precursor compound(s) and an etchant capable of etching the surface of the substrate and/or any previously applied coating, heating to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previous coating to be concentrated and recoated on the substrate or previously applied coating, and further heating, in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values, thereby obtaining on said substrate an electrocatalytically-active heterogeneous coating of a mixture of the metal oxides.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the temperature of the anolyte and the catholyte are maintained in the range of about 85° to about 105° C.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the pressure of the anolyte and catholyte compartments are maintained at about atmospheric pressure.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein the pressure of the anolyte and catholyte compartments are maintained at up to about 3 atmospheres pressure.
Claim 6
Dependent Claim
26 words
The process of claim 1 wherein circulation within each anolyte compartment and catholyte compartment is accomplished by displacement of liquids by the gaseous products of electrolysis.
Claim 7
Dependent Claim
25 words
The process of claim 1 wherein the anolyte and catholyte are recirculated through the anolyte and catholyte compartments of the cell by a pumping means.
Claim 8
Dependent Claim
25 words
The process of claim 6 wherein the ratio of the volume of the catholyte pumped to that of the anolyte pumped is greater than unity.
Claim 9
Dependent Claim
37 words
The process of claim 11 wherein the cathode comprises a layer of nickel metal having tightly adhered thereto a heterogeneous metal oxide coating, said heterogeneous metal oxide coating comprising nickel oxide and a platinum group metal oxide.
Claim 10
Dependent Claim
14 words
The process of claim 8 wherein the platinum group metal oxide is ruthenium oxide.
Claim 11
Dependent Claim
28 words
The process of claim 8 wherein the heterogeneous metal oxide coating also contains a modifier metal oxide in addition to the nickel oxide and platinum group metal oxide.
Claim 12
Dependent Claim
21 words
The process of claim 1 wherein the substrate has a layer of Ni between it and the heterogeneous metal oxide structure.
Claim 13
Dependent Claim
166 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a diaphragm to produce an aqueous solution of sodium hydroxide in the catholyte compartment, and chlorine in the anolyte compart-compartment, wherein the cathode of said process is a low hydrogen overvoltage cathode made by applying to an electroconductive substrate a coating solution of nickel oxide and ruthenium oxide precursor compounds and an etchant capable of etching the surface of the substrate and/or any previously applied coating, heating to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previous coating to be concentrated and recoated on the substrate or previously applied coating, and further heating, in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values, thereby obtaining on said substrate an electrocatalytically-active heterogeneous metal oxide structure comprising RuO 2 and NiO.
Claim 14
Dependent Claim
166 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a diaphragm to produce an aqueous solution of sodium hydroxide in the catholyte compartment, and chlorine in the anolyte compart-compartment, wherein the cathode of said process is a low hydrogen overvoltage cathode made by applying to an electroconductive substrate a coating solution of nickel oxide and ruthenium oxide precursor compounds and an etchant capable of etching the surface of the substrate and/or any previously applied coating, heating to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previous coating to be concentrated and recoated on the substrate or previously applied coating, and further heating, in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values, thereby obtaining on said substrate an electrocatalytically-active heterogeneous metal oxide structure comprising RuO 2 and NiO.
Claim 15
Dependent Claim
23 words
The process of claim 12 wherein the heterogeneous metal oxide structure comprises, predominantly, RuO 2 and NiO along with a modifier metal oxide.
Claim 16
Dependent Claim
26 words
The process of claim 12 wherein the heterogeneous metal oxide structure comprises, predominantly, RuO 2 and NiO along with ZrO 2 as a modifier metal oxide.
Claim 17
Dependent Claim
42 words
The process of claim 12 wherein the substrate has a layer of Ni between it and the heterogeneous metal oxide structure, wherein said heterogeneous metal oxide structure comprises, predominantly, RuO 2 and NiO, along with ZrO 2 as a modifier metal oxide.
Claim 18
Dependent Claim
86 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a cation exchange membrane to produce an aqueous solution of soldium hydroxide in the catholyte compartment, and chlorine in the anolyte compartment, wherein the cathode of said process comprises a low hydrogen overvoltage cathode comprising a nickel metal substrate having tightly adhered thereto a heterogeneous mixture of metal oxides, said mixture comprising nickel oxide and at least one platinum group metal oxide.
Claim 19
Dependent Claim
86 words
A process for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and a catholyte compartment separated by a cation exchange membrane to produce an aqueous solution of soldium hydroxide in the catholyte compartment, and chlorine in the anolyte compartment, wherein the cathode of said process comprises a low hydrogen overvoltage cathode comprising a nickel metal substrate having tightly adhered thereto a heterogeneous mixture of metal oxides, said mixture comprising nickel oxide and at least one platinum group metal oxide.
Claim 20
Dependent Claim
18 words
The process of claim 16 wherein the heterogeneous mixture of metal oxides comprises nickel oxide and ruthenium oxide.
Claim 21
Dependent Claim
20 words
The process of claim 16 wherein the heterogeneous mixture of metal oxides also contains zirconium oxide as a modifier oxide.
Claim 22
Dependent Claim
27 words
The process of claim 16 wherein the nickel metal substrate is of a configuration comprised of expanded mesh, punched plate, woven wire, sintered metal, plate, or sheet.
Claim 23
Dependent Claim
18 words
The process of claim 16 wherein the nickel metal substrate is of a configuration comprised of expanded mesh.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |