US4191618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of halogens in an electrolysis cell with catalytic electrodes bonded to an ion transporting membrane and an oxygen depolarized cathode
Assignee: De Nora SpA
•
Filing: 1978-07-06
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Granted: 1980-03-04
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Expires: 1998-07-06
Abstract
Abstract A halogen such as chlorine is generated by the electrolysis of aqueous halides in an electrolysis cell which includes an anode and a cathode separated by an ion transporting membrane. At least the cathode, which is a mass of noble metal catalytic particles and particles of a suitable binder, is bonded to the surface of the membrane. An oxygen containing gaseous stream is brought into contact with the bonded cathode to depolarize the cathode and prevent or limit discharge of hydrogen at the cathode, thereby substantially reducing the cell voltage.
Inventors
- 👤 Thomas G. Coker
- 👤 Russell M. Dempsey
- 👤 Anthony B. LaConti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:16
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/24; C25B1/34; C25B1/46; C25B9/00; C25B9/17; C25B9/19
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
99 words
A process of generating halogens by the electrolysis of aqueous halides which comprises electrolyzing an aqueous halide between an anode and a cathode electrode separated by an ion exchanging liquid and gas impervious membrane, said cathode comprising electroconductive catalytic material bonded to said membrane to provide a gas permeable electrode which forms part of a unitary electrode-membrane structure, applying a potential to the electrodes through separate electron conductive current collectors in physical contact with the electrochemically active catalytic material, passing an oxygen containing gaseous stream over said cathode to depolarize the cathode to prevent hydrogen evolution at said cathode.
Claim 2
Dependent Claim
99 words
A process of generating halogens by the electrolysis of aqueous halides which comprises electrolyzing an aqueous halide between an anode and a cathode electrode separated by an ion exchanging liquid and gas impervious membrane, said cathode comprising electroconductive catalytic material bonded to said membrane to provide a gas permeable electrode which forms part of a unitary electrode-membrane structure, applying a potential to the electrodes through separate electron conductive current collectors in physical contact with the electrochemically active catalytic material, passing an oxygen containing gaseous stream over said cathode to depolarize the cathode to prevent hydrogen evolution at said cathode.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the electrocatalyst is covered by a porous hydrophobic layer to prevent the formation of a water film over said electrode to ensure thereby penetration of oxygen to the electrocatalyst.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein the cathode catalyst comprises a mass of particles of a platinum group metal.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein said platinum group metal particles include reduced thermally stabilized electroconductive oxides thereof.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein said bonded catalytic cathodes are covered by a hydrophobic conductive film.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein said electrocatalytic material in said cathode is supported in a conductive screen.
Claim 8
Dependent Claim
20 words
The process of claim 6 wherein the screen supported catalytic material in said cathode is covered by a hydrophobic film.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the anode comprises an electrocatalytic material bonded to the surface of said membrane.
Claim 10
Dependent Claim
23 words
The process of claim 8 wherein said bonded electrocatalytic material in the anode comprises a mass of particles of a platinum group metal.
Claim 11
Dependent Claim
16 words
The process of claim 9 wherein said platinum group electrocatalytic particles include electroconductive reduced oxides thereof.
Claim 12
Dependent Claim
22 words
The process of claim 1 wherein oxygen is supplied to the cathode is at least at the stoichiometric rate for water formation.
Claim 13
Dependent Claim
19 words
The process of claim 11 wherein the oxygen flow to the cathode ranges between 1.5 and 3 times stoichiometric.
Claim 14
Dependent Claim
125 words
A process of generating chlorine which comprises electrolyzing an aqueous solution of hydrochloric acid between an anode and cathode electrode separated by an ion exchanging membrane said cathode comprising a layer of catalytic particles bonded to the ion exchanging membranes to provide a gas permeable electrode which forms a unitary electrode-membrane structure, applying a potential to the electrodes through separate electron conductive current collectors in physical contact with the electrochemically active actalytic particles, passing an oxygen containing gaseous stream over said cathode to depolarize the electrode cathode to form water and thereby prevent hydrogen discharge at said cathode, and said anode electrode comprises a plurality of electrocatalytic particles bonded to the surface of the ion exchange membrane to provide a gas and electrolyte permeable electrode.
Claim 15
Dependent Claim
125 words
A process of generating chlorine which comprises electrolyzing an aqueous solution of hydrochloric acid between an anode and cathode electrode separated by an ion exchanging membrane said cathode comprising a layer of catalytic particles bonded to the ion exchanging membranes to provide a gas permeable electrode which forms a unitary electrode-membrane structure, applying a potential to the electrodes through separate electron conductive current collectors in physical contact with the electrochemically active actalytic particles, passing an oxygen containing gaseous stream over said cathode to depolarize the electrode cathode to form water and thereby prevent hydrogen discharge at said cathode, and said anode electrode comprises a plurality of electrocatalytic particles bonded to the surface of the ion exchange membrane to provide a gas and electrolyte permeable electrode.
Claim 16
Dependent Claim
25 words
The process of claim 13 wherein the catalytic particles in said bonded anode electrode consists of graphite particles and particles of a platinum group metal.
Claim 17
Dependent Claim
15 words
The process of claim 14 wherein the platinum group metal particles include electroconductive oxides thereof.
Claim 18
Dependent Claim
18 words
The method according to claim 14 wherein said bonded cathode electrode is covered by a conductive hydrophobic layer.
Claim 19
Dependent Claim
28 words
The process of claim 13 wherein the bonded cathode electrode is covered by a hydrophobic layer to prevent formation of an oxygen blocking water film on said electrode.
Claim 20
Dependent Claim
20 words
The process of claim 13 wherein oxygen is supplied to the cathode at a rate in excess of 1.5 stoichiometric.
Claim 21
Dependent Claim
22 words
The process of claim 18 wherein the oxygen flow to the cathode is maintained in the range between 1.5 to 3 stoichiometric.
Claim 22
Dependent Claim
121 words
The process for generating chlorine and alkali which comprises electrolyzing an aqueous alkali metal chloride between an anode and a cathode separated by an ion exchanging membrane, at least the cathode electrode comprising a plurality of electroconductive catalytic particles bonded to said membrane to provide a gas and electrolyte permeable electrode to form a unitary electrode-membrane structure, applying a potential to the electrode through a separate electron conductive current collector in physical contact with the electrochemically active catalytic material bonded to the membrane, passing oxygen bearing gaseous stream to said cathode electrode to depolarize said electrode and to prevent hydrogen discharge at said electrode, said anode comprises a mass of electrocatalytic particles bonded to the surface of the ion exchange membrane.
Claim 23
Dependent Claim
121 words
The process for generating chlorine and alkali which comprises electrolyzing an aqueous alkali metal chloride between an anode and a cathode separated by an ion exchanging membrane, at least the cathode electrode comprising a plurality of electroconductive catalytic particles bonded to said membrane to provide a gas and electrolyte permeable electrode to form a unitary electrode-membrane structure, applying a potential to the electrode through a separate electron conductive current collector in physical contact with the electrochemically active catalytic material bonded to the membrane, passing oxygen bearing gaseous stream to said cathode electrode to depolarize said electrode and to prevent hydrogen discharge at said electrode, said anode comprises a mass of electrocatalytic particles bonded to the surface of the ion exchange membrane.
Claim 24
Dependent Claim
19 words
The process of claim 20 wherein the catalytic particles in the anode are particles of a platinum group metal.
Claim 25
Dependent Claim
21 words
The process of claim 21 wherein the noble metal particles in the anode are electroconductive oxides of said platinum group metal.
Claim 26
Dependent Claim
17 words
The process of claim 22 wherein the noble metal particles are reduced oxides of the noble metal.
Claim 27
Dependent Claim
20 words
The process of claim 20 wherein oxygen is supplied to the cathode at a rate in excess of 1.5 stoichiometric.
Claim 28
Dependent Claim
19 words
The process of claim 24 wherein the oxygen flow rate to the cathode ranges between 1.5 and 3 stoichiometric.
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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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |