CA1259052A - Durable electrode for electrolysis and process for production thereof - Google Patents

Durable electrode for electrolysis and process for production thereof

Info

Publication number
CA1259052A
CA1259052A CA000475042A CA475042A CA1259052A CA 1259052 A CA1259052 A CA 1259052A CA 000475042 A CA000475042 A CA 000475042A CA 475042 A CA475042 A CA 475042A CA 1259052 A CA1259052 A CA 1259052A
Authority
CA
Canada
Prior art keywords
electrode
oxide
intermediate layer
group
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000475042A
Other languages
French (fr)
Inventor
Hiroshi Asano
Kazuhiro Hirao
Takayuki Shimamune
Ryuta Hirayama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
De Nora Permelec Ltd
Original Assignee
Permelec Electrode Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP59038733A external-priority patent/JPS60184690A/en
Priority claimed from JP59038734A external-priority patent/JPS60184691A/en
Application filed by Permelec Electrode Ltd filed Critical Permelec Electrode Ltd
Application granted granted Critical
Publication of CA1259052A publication Critical patent/CA1259052A/en
Expired legal-status Critical Current

Links

Abstract

ABSTRACT OF THE DISCLOSURE

An electrolytic electrode which exhibits high durability when used in electrochemical processes in which the generation of oxygen is involved and a process for the production of the same. The electrolytic electrode comprises (a) an electrode substrate of an electrically-conductive metal;
(b) an electrode coating of an electrode- active substance; and (c) an intermediate layer provided between the electrode substrate (a) and the electrode coating (b), wherein the intermediate layer (a) comprises a mixed oxide of:
(i) an oxide of at least one member selected from the group consisting of titanium (Ti) and tin (Sn), each having a valence number of 4, and (ii) an oxide of at least one member selected from the group consisting of aluminum (Al), gallium (Ga), iron (Fe), cobalt (Co), nickel (Ni) and Thallium (Tl), each having a valence number of 2 or 3, and platinum (Pt) dispersed in said mixed oxide.

Description

~s~s~

DURABLE ELECTRODE FOR ELECTROLYSIS
AND PROCESS FOR PRODUCTION THEREOF

The present invention relates to electrodes for electrolysis (hereinafter referred to as "electrolytic electrodes") and a process for the production of the same.
5More particularly, the present invention relates to electrolytic electrodes showing high durability, i.e., a long service life, when used in electrochemical processes, e.g., an aqueous solution in which the generation of oxygen at the anode is involved, and a process for the 10production of the same.
BACKGROUND OF THE INVENTION
Heretofore, electrolytic electrodes comprising a substrate of valve metals, e.g., titanium (Ti), have been used as superior insoluble metal electrodes in the field 15of electrochemistry. In particular, they have been widely used as anodes for the generation of chlorine in the salt (sodium chloride) electrolytic industry. In addition to Ti, tantalum ~Ta), niobium (Nb), zirconium (Zr), hafnium (Hf), vanadium (V), molybdenum (Mo), tungsten (W), etc.
20are known as valve metals.
These metal electrodes are produced by coating metallic titanium with various electrochemically active 13~

~g~52 1 substances such as platinum group metals and their oxides.
Examples of such platinum group metals and their oxides are described in, e.g., U.S. Patent Nos. 3,632,498 and 3,711,385. These electrodes can maintain a low chlorine overvoltage over a long period of time as electrodes for the generation of chlorine.
Howèver, when the above metal electrodes are used as anodes in electrolysis for the generation of oxygen or electrolysis in which the generation of oxygen is involved, the anode overvoltage gradually increases.
In extreme cases, the anode is passivated and thus it becomes impossible to continue the electrolysis.
The phenomenon of passivation of the anode is believed to be caused mainly by the formation of electrically non-conductive titanium oxides that result from (1) the oxidation of the titanium base material with oxygen by the electrode coating-constituting oxide substance itself; (2) oxygen diffusion-permeating through the electrode coating; or (3) the electrolyte.
Formation of such electrically non-conductive oxides in the interface between the base material and the electrode coating causes the electrode coating to peel off. This creates problems such as a breakdown of the electrode.
Electrochemical processes in which the anode ~S90~

1 product is oxygen, or where oxygen is generated at the anode as a side reaction, include: (1) electrolysis using a sulfuric acid bath, a nitric acid bath, an alkali bath or the like; (2) electrolytic separation of chromium (Cr), copper (Cu), zinc (Zn), or the like; (3) various types of electroplating; (4) electrolysis of dilute salt water, sea water, hydrochloric acid, or the like; and (5) electrolysis for the production of chlorate, and so forth.
These processes are all industrially important. However, the above-described problems have hindered metal electrodes from being used in these processes.
U.S. Patent No. 3,775,284 discloses a technique to overcome passivation of the electrode due to permeation of oxygen. In this technique, a barrier layer of a platinum (Pt)-iridium (Ir) alloy, or of an oxide of coba lt (Co), manganese (Mn), lead (Pb), palladium (Pd), and Pt is provided between the electrically-conductive substrate and the electrode coating.
The substances forming the intermediate barrier layer prevent the diffusion-permeation of oxygen during electrolysis to some extent. However, these substances are electrochemically very active and therefore, react with the electrolyte passing through the electrode coating. This produces electrolytic products, e.g., gas, on the surface of the intermediate barrier layer which ~259052 gives rise to additional problems. For example, the adhesion of the electrode coating is deteriorated due to physical and chemical influences of the electrode coatiny peeling off before the life of the substance of the electrode coating is over. Another problem is the corrosion resistance of the resulting electrodes is poor. Thus, the method disclosed in U.S. Patent No.
3,775,284 fails to produce electrolytic electrodes which have high durability.
Japanese Patent Application (OPI) No. 40381/76 (the term "OPI" used herein refers to a "Published Unexamined Patent Application") of Hooker Chemical and Plastics Corp. was published on April 5, 1976 and discloses an intermediate coating layer comprising tin oxide coped with antimony oxide for coating the anode.
However, the anode used is an anode intended for the generation of chlorine, and hence an electrode provided with an intermediate coating forming substance disclosed in the above publication does not show the generation of oxygen.
U.S. Patent No. 3,773,555 discloses an electrode in which a layer of an oxide of, e.g., Ti, and a layer of a platinum group metal or an oxide thereof are laminated and coated on the electrode. However, this electrode has the problem that when it is used in electrolysis in which the generation of o~ygen is involved, passivation occurs.

,, ., ~ .
, .

~2~9~5~:

S UMMARY OF THE I NVENT I ON
The present invention provides the ability to overcome the above-described problems. ~ore specifically, an object of the present invention is to provide electrolytic electrodes which are especially suitable for use in electrolysis in which the generation of oxygen is involved, i.e., which resist passivation and have high durability.
Another object of the present invention is to provide a process for producing such electrolytic electrodes.
The above described objects are met by:
(I) An elecrtrolytic electrode comprising (a) an electrode substrate of an electrically-conductive metal;
(b3 an electrode coating of an electrode active substance; and (c3 an intermediate layer provided between the electrode substrate and the electrode coating, wherein the intermediate layer (c) comprises a mixed oxide of (i) an oxide of at least one member selected from the group consisting of titanium (Ti) and tin (Sn), each having a valence number of 4, and (ii) an oxide of at least one member selected from the group consisting of aluminum (Al), gallium (Ga), iron (~e), cobalt (Co), nickel (Ni) and ~90~ii2 1 thallium (Tl), each having a valence number of 2 or 3, and platinum (Pt~ dispersed in the mixed oxide; and (II) A process for producing an electrolytic electrode, comprising the steps of:
(1) coating an electrode substrate of an electrically conductive metal with a solution containing (i) salt(s) of Ti and/or Sn, (ii) salt(s) of at least one metal selected from the ~roup consisting of Al, Ga, Fe, Co, Ni and Tl, and (iii) a salt of Pt to provide a coated substrate;
(2) heating in an oxidizing atmosphere the electrode substrate coated with said solution in step (1), thereby forming on the electrode substrate an intermediate layer comprising a mixed oxide of (i) an oxide of at least one member selectecl from the group consisting of Ti and Sn, and (ii) an oxide of at least one member selectecl from the group consisting of Al, Ca, Fe, Co, Ni, Tl, and Pt dispersed in the mixed oxide, and
(3) subsequently coating the inter~ediate layer with a layer of an electrode active substance.
DETAI~E_D_DESCRIPTION OF THE INVENTION
The present invention is based on the discovery , ~ . :' .

. . .

-~ -52 1 that the provision of the intermediate layer between the substra-te and the electrode coating enables one to obtain an electrode which can be used with sufficient durability as an anode for electrochemical processes in which the generation of oxygen is involved.
The intermediate layer of the present invention is corrosion-resistant and is electrochemically inactive.
A unction of the intermediate layer is to protect the electrode substrate, e.g., Ti, so as to prevent passivation of the electrode without reducing its electrical conductivity. At the same time, the intermediate layer acts to enhance the adhesion or bonding between the base material and the electrode coating~
Accordingly, the present invention provides electrolytic electrodes which have sufficient durability when used in electrolysis for the generation of oxygen or electrolysis in which oxygen is generated as a side reaction. Such processes have heretofore been considered difficult to perform with conventional electrodes.
The present invention is explained in greater detail below.
In the production of the electrode substrate of the present invention, corrosion-resistant, electrically-conductive metals, e.g., Ti, Ta, Nb, and Zr, and their base alloys can be used. Suitable examples are metallic 1 Ti, and Ti-base alloys, e.g., Ti-Ta-Nb and Ti-Pd, which have heretofore been commonly used. The electrode base material can be in any suitable form such as in the form of a plate, a perforated plate, a rodr or a net-like member.
The electrode substrate of the present invention may be of a type coated with a platinum group metal such as Pt or a valve metal such as Ta and Nb in order to increase corrosion resistance or enhance the bonding between the substrate and the intermediate layer.
The intermediate layer is provided on the above-described electrode substrate and comprises a composite having Pt dispersed in a mixed oxide of an oxide of Ti and/or Sn having a valence number of 4 and an oxide of at least one member selected from the group consisting of Al, Ga, Fe, Co, Ni and Tl having a valence number of 2 or 3.
An electrolytic electrode comprising an electrode substrate of an electrically conductive metal such as Ti and an electrode coating of a metal oxide, wherein an intermediate layer of a mixed oxide of an oxide of Ti and/or Sn and an oxide of Ta and/or Nb is provided between the substrate and the electrode coating is disclosed in U.S. Patent Nos. 4,471,006 and 4,484,999.
This electrode is resistant to passivation and excels in durability. The intermediate layer used in the electrode : ~.

~s~0~2 1 exhibits good conductivity as an N-type semiconductor.
However, since the intermediate layer has limited carrier concentration, further improvement with respect to conductivity was desired.
Due to the concept of providing an intermediate layer possessing much higher conductivity -than the intermediate layer of the electrode of these patents, the present invention has made it possible to produce an electrode which eliminates the drawback suffered by the electrode of these patents and offers still higher conductivity and durability.
As the substance to make up the intermediate layer contemplated by this invention, a composite having Pt dispersed in a mixed oxide of an oxide of Ti and/or Sn and an oxide of at least one member selected from the group consisting of Al, Ga, Fe, Co, Ni and Tl has been demonstrated to suit the purpose of this invention and provide an outstanding effect. The substance of the intermediate layer provides excellent resistance to corrosion, exhibits no electrochemical activity, and possesses ample conductivity. The term "oxide" or "mixed oxide" is meant to embrace solid solutions of metal oxides and metal oxides which are nonstoichiometric or have lattice defects. As used in this invention, the expression "TiO2"~ "Sno2 ~ "A123 ' Ga2O3 , FeO , 1 ~Fe2O3~, "cOOn, "Co2O3n, "NiOn, nT12O3n, etc. and the term ~mixed oxide" embrace solld solutions of such metal oxides and those metal oxides nonstoichiometric or having lattice defects, for the sake of convenience.
The substance of the intermediate layer, as described above, is any combination of Pt substantially in a metallic form, an oxide of a metal having a valence of 4 ~Ti or Sn), and an oxide of a metal having a valence of 2 or 3 (Al, Ga, Fe, Co, Ni and Tl).
Specifically, any of the mixed oxides TiO2-A1205~ TiO2-Ga203, SnO2-FeO, SnO2-CoO, TiO2-SnO2-Co203, TiO2-SnO2-NiO, TiO2-Al2O3-Tl2O30 SnO2-Ga2O3 Fe23 and TiO2-SnO2-A12O3-Ga2O3 can be used advantageously to achieve an ample effect when combined with Pt dispersed therein.
The proportions of the component oxides of the mixed oxide are not specificaly defined and a wide range of proportions may be used. For prolonged retention of durability and conductivity of the electrode, it is desirable for the ratio of the oxide of the tetravalent metal to the oxide of the divalent or trivalent metal to be in the range of about 95:5 to about 10:90 by the mol of metal. The amount of Pt to be dispersed in the mixed oxide desirably falls in the range of about 1 to 20 mol%
based on the total amount of substance making up the intermediate layer.

.~,~ ..

~59Qt~2 1 The formation of the intermediate layer in the electrode can be advantaqeously effected by the thermal decomposition method which comprises the steps of applying a mixed solution containing chlorides or other salts of component metals destined to make up the aforementioned intermediate layer to the metal substrate and then heating the coated substrate under an atmosphere of an oxidizing gas at temperatures of about 350 to 600C thereby producing a mixed oxide. Other methods may be adopted if desired so long as the method is capable of forming a homogeneous, compact coating having Pt dispersed in an electroconductin~ mixed oxide. By the afore-mentioned thermal decomposition method, Ti, Sn, Al, Ga, Fe, Co, Ni and Tl are readily converted into their corresponding oxides while Pt compound is merely decomposed thermally into metallic platinum and is not converted into an oxide at all.
The amount of the substance of the intermediate layer to be applied to the substrate preferably exceeds about 5 x 10 3 mol/m calculated as metal. If the amount is less than about 5 x 10 3 mol/m2 mentioned above, the intermediate layer consequently formed does not provide sufficient effects.
The thus-formed intermediate layer i5 then , ~25~
1 coated with an electrode active substance which is electrochemically active to produce the desired product.
Suitable examples of such electrode active substances are metals, metal oxides or mixtures thereof, which have superlor electrochemical characteristics and durability.
The type of the active substance can be determined appropriately depending on the electrolytic reaction in which the electrode is to be used. Active substances particularly suitable for the above-described electrolytic processes in which the generation of oxygen is involved include: platinum group metal oxides, and mixed oxides of platinum group metal oxides and valve metal oxides.
Typical examples include: Ir oxide, Ir oxide-Ru oxide, Ir oxide-Ti oxide, Ir oxide-Ta oxide, Ru oxide-Ti oxide, Ir oxide-Ru oxide-Ta oxide, and Ru oxide-Ir oxide-Ti oxide.
The electrode coating can be formed in any suitable manner, e.g., by thermal decomposition, electrochemical oxidation, or powder sintering. A
particularly suitable technique is the thermal decomposition method as described in detail in U.S. Patent Nos. 3,711,385 and 3,632,498.
The exact reason why the provision of the intermediate layer, i.e., that layer of the mixed oxide of
4-valent and 2- or 3-valent metals and Pt dispersed therein~ between the metal electrode substrate and the ~S9(~1SZ
1 electrode active coating produces the above-described results is not well understood. However, while not desiring to be bound the reason is believed as follows.
Crystallographically, it is confirmed that Al, Ga, Fe, Co, Ni and Tl are in substantially of 6-coordination state and the ionic radii of these metals in a 6-coordinatLon state vary within the range between the value by about 10% larger than and the value by about 10%
smaller than that of Ti or Sn. This indicates that the mixed oxides of the metals form a layer of a uniform, dense solid solution or mixed oxide composed mainly of a rutile type crystal phase. Since such an intermediate layer comprising a composite of Pt dispersed in such a mixed oxide has a high resistance to corrosion, the surface of the substrate covered with the dense metal mixed oxide intermediate layer is protected from oxidation, and hence passivation of the substrate is prevented.
In the intermediate layer, the 4-valent and 2-or 3-valent metals are present simultaneously as oxides and Pt is dispersed in the mixed oxides. Therefore, according to generally known principles of Controlled Valency, the intermediate layer becomes a p-type semi-conductor having a very high electrical conductivity. Moreover, the Pt dispersed in the mixed oxide confers high electron conductivity to the mixed oxide.

~:S9052 1 Also, since Pt is a substance which offers extremely high resistance to corrosion and has very high potential for the generation of oxygen, it is deficient in electrochemical activity and generally does not react with the electrode and, thus functions to enhance the durability of the electrode. Where metallic Ti, for example, is used as a substrate, even when electrically non-conductive Ti oxides are formed on the surface of the substrate during the production of the electrode or during the use of the electrode in electrolysis, the 2- or 3~
valent metal in the intermediate layer diffuses and renders the Ti oxides semi-conductors. Accordingly, the electrical conductivity of the electrode is maintained and passivation is prevented.
In addition, the intermediate layer substance which is composed mainly of rutile type oxides having dispersed therein Pt enhances the adhesion or bonding between the substrate of, e.g., metallic Ti, and the electrode active coating of, e.g., platinum group metal oxides and valve metal oxides, and hence increases the durability of the electrode.
The present invention is described in greater detail by reference to the following examples which are in no way intended to limit the present invention. Unless 1otherwise indicated herein, all parts, percents, ratios and the like are by weight.

A commercially available Ti plate having a 5thickness of 1.5 mm and a size of 50 mm x 50 mm was degreased with acetone. Thereafter, the plate was subjected to àn etching treatment using a 20~ aqueous hydroc~loric acid solution maintained at 105C. The thus treated Ti plate was used as an electrode substrate.
A mixture of 10% hydrochloric acid mixed solution of cobalt chloride, containing 10 g/l of Co, titanium chloride containing 10.4 g/l of Ti and a 10~
hydrochloric acid solution of chloroplatinic acid containing 10 9/l of Pt, was coated on the Ti plate 15electrode substrate and dried. Thereafter, the plate was heated for 10 minutes in a muffle furnace maintained at 500C. This procedure was repeated four times to form an intermediate layer of a TiO2-Co2O3 mixed oxide ~molar ratio of Ti to Co = 80:20) containing o 5 g~m2 of Pt dispersed therein on the Ti ~ubs~a~e.
A butanol solution of iridium chloride containing 50 g/l of Ir was coated on the above-formed intermediate layer and heated for 10 minutes in a muffle furnace maintained at 520C. .This procedure was repeated 25three times to produce an electrode with Ir oxide, ~ , .

`

~ S~ ~ 2 1 containing 3.0 y/m of Ir, as an electrode active substance.
With the thus-produced eiectrode as an anode and a graphite plate as a cathode, accelerated electrolytic testing was performed in a 150 9/1 sulfuric acid electrolyte at 60C, and at a current density of 100 A/dm2. The results demonstrated that this electrode could be used in a stable manner for 420 hours.
For comparison, an electrode was produced in the same manner as above except that the intermediate layer did not contain Pt. This electrode was also tested in the same manner as above. The results demonstrated that this electrode was passivated in 280 hours and could no longer be used.

Electrodes were prepared by following the procedure of Example 1, except that the substance for the intermediate layer and that for the active coat of electrode were varied as indicated in Table 1 below. The thus prepared electrodes were subjected to accelerated electroLysis testing for performance. The electrolysis was conducted in an aqueous 150 g/liter sulfuric acid solution as the electrolyte at a temperature of 80Ct and at a current density of 250 A/dm2, with a platinum plate as the cathode. The results obtained are shown in Table 1 below.

.J

~2Si9~5;~

1 Table 1 Intermediate Electrode Active Service Run No. SubstateLayer Substance Life (hours) 1 Ti Pt-TiO2-Al2o3 IrO2 75 (75:25) 2 TiPt-Tio2o3-Fe2o3 IrO2 80 (80:20) 3 Ti Pt-Tio2-co2o3- IrO2 80 SnO2 - (40:50:10) 4 Ti Pt-TiO2-Al2o3- RuO2-IrO2 45 Ga23 (50:50) (80:10:10) Ti Pt-Tio2-Tl2o3 RUo2-Iro2 38 (70:30) (50:50) 6 Ti Pt-Tio2-Al2o3- RuO2-IrO2 55 Fe23 (30:70) (30:40:30) 7 Ti TiO2-Al2O3 RUo2-Iro2 10 (comparison) (80:20) (50:50) Note: The numerical values given in parentheses represent mole ratios of component metals excluding Pt. The amount of Pt in the intermediate layer was 0.5 g/m2 for each electrode. The amount of the electrode active substance was invariably 3 g/m2 as metal component.

From the results in Table 1, it can be seen that the electrodes of this invention incorporating a Pt-containing intermediate layer had a decisively longer service life and exhibited higher durability than the electrode (comparison) incorporating a conventional layer which did not contain any Pt.

3~59~

An electrode was prepared by following the procedure of Example 1, except that a mixed oxide of SnO2-NiO having Pt dispersed therein (Sn 80:Ni 20 by metal mole ratio, with Pt dispersed at a ratio of 1.3 g/m2) was used as the intermedite layer and similar testing was conducted. The electrolysis testing was carried out in an aqueous 12N NaOH solution at a temperature of 95C and at a current density of 250 A/dm with a platinum plate used as the cathode.
This electrode had a service life of 38 hours.
Another electrode was prepared for comparison by repeating the same procedure, except that the Pt was omitted from the intermediate layer. This electrode for comparison had a service life of 22 hours. Thus, the electrode of this invention was demonstrated to have very high durability as compared with the other electrode.
While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims (8)

WHAT IS CLAIMED IS:
1. An electrolytic electrode comprising:
(a) an electrode substrate of an electrically-conductive metal;
(b) an electrode coating of an electrode active substance; and (c) an intermediate layer provided between the electrode substrate (a) and the electrode coating (b), wherein said intermediate layer (c) comprises a mixed oxide of:
(i) an oxide of at least one member selected from the group consisting of titanium and tin, each having a valence number of 4, and (ii) an oxide of at least one member selected from the group consisting of aluminum, gallium, iron, cobalt, nickel and thallium, each having a valence number of 2 or 3, and platinum dispersed in said mixed oxide.
2. An electrode as claimed in Claim 1, wherein said electrode substrate (a) is one of titanium, tantalum, niobium, or zirconium or an alloy thereof.
3. An electrode as claimed in Claim 1, wherein said intermediate layer (c) comprises an electroconductive mixed oxide of (i) TiO2 and/or SnO2 and (ii) at least one member selected from the group consisting of Al2O3, Ga2O3, FeO, Fe2O3, CoO, Co2O3, NiO
and Tl2O3, and Pt dispersed in said mixed oxide.
4. An electrode as claimed in Claim 1, wherein said electrode active substance contains a platinum-group metal or an oxide thereof.
5. A process for producing an electrolytic electrode, comprising the steps of:
(1) coating an electrode substrate of an electrically conductive metal with a solution containing (i) salt(s) of Ti and/or Sn, (ii) salt(s) of at least one metal selected from the group consisting of Al, Ga, Fe, Co, Ni and Tl, and (iii) a salt of Pt to provide a coated electrode substrate;
(2) heating in an oxidizing atmosphere the electrode substrate coated with said solution in step (i) thereby forming on said substrate an intermediate layer comprising a mixed oxide of (i) an oxide of at least one member selected from the group consisting of Ti and Sn, and (ii) an oxide of at least one member selected from the group consisting of Al, Ga, Fe, Co, Ni, Tl, each having a valence number of 2 or 3, and Pt dispersed in said mixed oxide;
wherein said intermediate layer is formed by heating the coated electrode substrate in an oxidizing atmosphere at about 350° to 600°C; and (3) subsequently coating said intermediate layer with a layer of an electrode active substance.
6. A method as claimed in Claim 5, wherein said coating of the intermediate layer with said electrode active substance is carried out by thermal decomposition.
7. A process as claimed in Claim 5, wherein said electrode substrate is one of titanium, tantalum, niobium, or zirconium or an alloy thereof.
8. A process as claimed in Claim 5, wherein said electrode active substance contains a platinum-group metal or an oxide thereof.
CA000475042A 1984-03-02 1985-02-25 Durable electrode for electrolysis and process for production thereof Expired CA1259052A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP59038733A JPS60184690A (en) 1984-03-02 1984-03-02 Durable electrode and its manufacture
JP38734/84 1984-03-02
JP38733/84 1984-03-02
JP59038734A JPS60184691A (en) 1984-03-02 1984-03-02 Durable electrode and its manufacture

Publications (1)

Publication Number Publication Date
CA1259052A true CA1259052A (en) 1989-09-05

Family

ID=26378020

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000475042A Expired CA1259052A (en) 1984-03-02 1985-02-25 Durable electrode for electrolysis and process for production thereof

Country Status (1)

Country Link
CA (1) CA1259052A (en)

Similar Documents

Publication Publication Date Title
US4584084A (en) Durable electrode for electrolysis and process for production thereof
US4468416A (en) Electrolytic electrodes having high durability and process for the production of same
US4481097A (en) Durable electrode for electrolysis
US4581117A (en) Durable electrode for electrolysis and process for production thereof
US4288302A (en) Method for electrowinning metal
US4484999A (en) Electrolytic electrodes having high durability
US5098546A (en) Oxygen-generating electrode
CA1214452A (en) Electrolytic cell anode
CA1184871A (en) Low overvoltage hydrogen cathodes
US4086157A (en) Electrode for electrochemical processes
EP0262369B1 (en) Lead oxide-coated electrode for use in electrolysis and process for producing the same
JPH0261083A (en) Anode for generating oxygen and production thereof
JPH02282491A (en) Oxygen generating anode and production thereof
CA1259052A (en) Durable electrode for electrolysis and process for production thereof
JPH02179891A (en) Anode for generate oxygen and production thereof
JP3941898B2 (en) Activated cathode and method for producing the same
JPH05230682A (en) Electrolytic electrode
JPH02282490A (en) Oxygen generating anode and production thereof

Legal Events

Date Code Title Description
MKEX Expiry