CA1129809A - Electrolysis electrode with coating of tin dioxide and platinum group metal - Google Patents
Electrolysis electrode with coating of tin dioxide and platinum group metalInfo
- Publication number
- CA1129809A CA1129809A CA324,281A CA324281A CA1129809A CA 1129809 A CA1129809 A CA 1129809A CA 324281 A CA324281 A CA 324281A CA 1129809 A CA1129809 A CA 1129809A
- Authority
- CA
- Canada
- Prior art keywords
- coating
- weight
- platinum
- electrode
- tin
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
- C25B11/093—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Abstract
ELECTRODES FOR ELECTROLYTIC PROCESSES, ESPECIALLY
PERCHLORATE PRODUCTION
ABSTRACT
An electrode especially for the production of chlorates and perchlorates comprising an electrically-conductive corrosion-resistant substrate having an electrocatalytic coating which is preferably a mixture of 40 to 85 parts by weight of platinum, 0 to 20 parts by weight of palladium and 15 to 40 parts by weight (as tin metal) of tin dioxide.
PERCHLORATE PRODUCTION
ABSTRACT
An electrode especially for the production of chlorates and perchlorates comprising an electrically-conductive corrosion-resistant substrate having an electrocatalytic coating which is preferably a mixture of 40 to 85 parts by weight of platinum, 0 to 20 parts by weight of palladium and 15 to 40 parts by weight (as tin metal) of tin dioxide.
Description
J~12~8~9 1 ELECTRODES FOR ELECTROLYTIC PROCESSE,S, ESPECIALLY
PERCHLOR~TE PRODUCTION.
TECHNICAL FIELD
The invention relates to electrodes for use in electxol~tic processes, of the type comprising an electrically~conductive and corrosion-resistant sub-strate having an electrocatalytically-active surface coating, and to electrolytic processes using such electrodes, especially (~ut not exclusively) as anodes for the production of chlorates, perchlorates and other persalts and percompounds including organic peroxyacids.
BACKGROUND ART
For tile pxoduction of perchlorate, various anode materials have ~een ~lsed com~ercially, including smooth massive platinum, platinized t~tanium or tantalum (despite a tendency to produce excess oxygen) and lead dioxide coated on titanium or graphite, althou~h t~ese lead dioxide anodes have a high overvoltage and wear rapidly, Some proposals have already been made to con~ine platinum group metals and tin dioxide in electrode coatin~ materials. For example, U.S. Patent Specifica-tion 3,701,724 mentioned an anode for chlorine - production having a coating consisting essentially of ';
.. ~
~L29~3~9 1 a minor amount o~ a platinum group metal and/or platinum group metal oxides with a major amount of Sn02, Sbz05, Sb203 or Ge02 and mixtures thereof. However, the claims and examples of this patent are directed solely to such coatings containing platinum group metal oxides and there is no enabling disclosure of a coating containing a platinum group metal. Also, IJ.S. Patent Sp~cification - 3,882,002 proposed an anode for c,llorine production havin~ a valve metal substrate coated with an intermediate layer of tin dioxide which ~as covered with an outer la~er of a platinum group metal or oxide thereof. Neither of these proposals was directed to impro~ing electrolytic performance in the production of percompounds.
DISCLO~UR~ OF INVENTION
An object of the invention therefore is to provide an improved electrode suitable for use as an anode for the production of perchlorates and other persalts, but which may also be used in other applications, such as chlorate production.
2Q According to a main aspect of the invention, an electrode comprises an electrically-conductive corrosion-resistant substrate having an electrocatalytic coating and is characterized in -that the coating contains a mixture of at least one platinum group metal and tin ~`
dioxide dis~ersed in one another throughout the coating in the ratio of 8.5:1 to 3:2 by weight of the platinum group metals to the tin (as metal) of the tin dioxide.
The platinum group metal/tin dioxide coating may also contain a sta~ilizer/binder, for example a compound such as titanium dioxide r zirconium dioxide or s~licon dioxide. Additionally, the coating may include a filler, e.g. particles or fibres of an inert material such as silica or alumina, particles of titanium, or ~9~
1 z~rconium silicate. Furthermoxe, the coating may also contain, e.g, as ~ dopant the tin dioxide in a quantity up to about 30~ b~ welyht ~as metal) of the tin dioxide, of at least one additional metal or oxide of zinc, cadmium, arsenic, antimony, bismuth, selenium and tellurium.
Sucn stabilizers or binders, ~illers and dopants generally do not account for more tnan 70% of the total weight of the coating, usually far less. In the case of antimony trioxide or bismuth trioxide as dopant, the preferred amount corre$ponds to a ratio expressed as parts by weight of Sb~Bi:Sn ~as metal) of at most ahout 1:4 to about l:lO or even as low as 1:100.
The platinum group metals are ruthenium, rihodium/ palladium, osmium, iridium and platinum.
Platinum is the preferred platinum group metal in the coating, when a single metal is present, especially in anodes for perchlorate production. However, it is understood that alloys such as platinum-iridium and platinum-rhodium, also are useful for other applications.
An allo~ of platinum-palladium containing up to 20%
palladium by weight of the alloy has given very satis-factory results for perchlorate production. Also, in some instances, it may be advantageous to alloy the platinum group metal(s) with one or more non-platinum group metals, for example an alloy or an intermetallic compound witn one of the valve metals titanium, ~irconium, hafnium~ vanadium, niobium and tantalum, or with another transition metal, for example a metal such as tungsten, manganese or cobalt.
The substrate may consist of any of the afore-mentioned valve metals or alloys thereof, porous sintered titanium being preferred. However, other electrically-conductive and corrosion-resistant substrates may be used, such as expanded graphite.
The platinum grou~ metal(s) and tin dioxide 1 with possible additional dopants, such as antimon~
trioxide or bismuth trio~ide, may be co-deposited chemically from solutions of appropriate salts ~lhlch are painted, sprayed or otherwise applied on the substrate and then subjected to heat treatment, this process being repeated until a suffi~iently thick layer has been built up.
Alternatively, thin layers of different components te.g. alternate platinum or Pt/Pd alloy ~0 layers and layers of pure or doped tin dioxide) ~an be built up in such a way that the components are effectively mixed and dis~ersed in one another through-out the coating, possibly witll diffusion between the layers, in contrast to the known prior art coatin~s such as that of U. S. Patent Specification 3,882,002, in which the tin dioxide was applied as a separate intermediate layer covered by a platinum group metal.
Using this procedure of applying alternate layers, it is possible to deposit thin layers of platinum galvanically, which is advantageous, because gal-vanically-deposited platinum has a lower oxygen evolution potential than chemi-deposited platinumu The platinum-group metal or alloy/-tin dioxide layer may be applied directly to the substrate, or to an intermediate layer, e.g. of co-deposited tin and antimony oxides or tin and bismuth oxides, or to inter-mediate layers consisting of one or more platinum group metals or their oxides, mixtures or mixed crystals of platinum group metals and valve metal oxides, inter-metallics of platinum group metals and non-platinum group metals, and so for-tn.
In a preferred embodiment, the coating comprises 4Q to 85 parts by weight of platinum, 0 to 20 parts by wei~ht of palladium and 15 to 40 parts by weight (as Sn metal~ of tin dioxide on a titanium, tantalum or . .
` ~29~
1 titanium~tantalum alloy substrate. This emBodiment of an electrode o~ the inventionJ ~hen used as anode for perchlorate or persulphate production, has been found to have selective properties favouring the persalt production while hindering oxygen evolution. The platinum metal acts as a catalyst ~or persalt production.
The tin dioxide acts as an oxygen evolution inhibitor by blocking perox~de decomposition, which can be reyarded as the intermediate step of the un~anted oxygen evolution reaction. Finall~, ~he palladium acts as a diluent for the relatively more expensive platinum, without adversely affecting the ox~gen inhibition effect of the tin dioxide.
Another aspect of the 'invention is a process for the production of chlorates, perchlorates and other percompounds, e.y. persul~hates, which is characterised by using as anode an electrode according to the invention, as defined above.
BRIEF DESCRIpTION OF DRAWINGS
In the accompanying drawings:
Fig. 1 shows a graph of the faraday efficiency of oxygen evolution as ordinate plotted against the tin content of the electrode coating as abscissa, the electrode being that described below in detail in Example I;
Fig. 2 shows a graph of the faraday efficiency of oxygen evolution as ordinate plotted against the palladium content of the electrode coating as abscissa, the electrode being that described below in detail in Example II.
BEST MODES FOR CARRXING OUT HE INVENTION
The following Examples are given to illustrate - , , ~ . , , ~ , 1 the invention, E~AMPLE I
Titanium coupons measurin~ 10 x 10 x 1 mm were sandblasted and etched in 20% hydrochloric acid and were thoroughly washed in water. The coupons were then coated with an aqueous solution of chlorides of platinum and tin in different weight ratios~ dried at 95 to 100C
and then heated at 450C for 15 minutes in an oven ~7ith forc d air ventilation. The procedure was repeated five times and tlle coupons were given a final heat treatment at 450C for 60 minutes. The coatings so produced con-tained SnQ2 and platinum metal dispersed in one another.
The coated coupons were tested as anodes for the production of sodium perchlorate by the electroly-sis of a solution consisting of lOOg/l NaC103, 400g/1 NaC104 and 5g/1 Na2CrO4 at 30C using a stainless stPel cathode and a current densit~ of 2KA/m . Sodium chlorate was supplied and sodium perchlorate removed to maintain the concentrations in the electrolyte at a steady state.
2Q The faraday efficiency of the oxygen evolution reaction(i.e. the unwanted side reaction in perchlorate production) was measured as a function of the percentage by weight of ~in (as metal) in the mixe'd Pt-SnO2 coating. The results obtained are shown in Fig. 1, from which it can be seen that there is an optimum oxygen-inhibition effect for a tin content in the range of about 25%~35% of the total weight of tin and platinum metals, and a very appreciable inhibition of oxygen evolution for a tin content in the larger ran~e from about 15% to about 40%.
EXi~MPLE_II
Titanium coupons were coated as in Example I, but using various coating solutions containin~ platinum, .
~z~
1 palladium and tin chlorides, to produce mixed Pt~Pd~SnO2 coatings having compositions as fol low5:
.
Coatins Composition (% wei~ht of metal) Pt ¦ Pd ~ SnO2 _ . .. ~
0 ~ 30 j 30 ! 30 ?0 , 30 ' 25 ' 30 These coupons were tested as anodes for perchlorate production under the same conditions as used in Example I~ The faraday efficiency of the unwanted lS oxygen evolution reaction was measured as a function of the palladium metai content, and the results are shown in Fig. 2. This graph shows that, for a palladium content up to 20%~ the faraday efficiency remained low, i.e. the palladium did not.adversely affect the performance of the coating to inhibit oxygen evolution. However, above the critical Pd content of 20%~ the faraday efficiency abruptly increasedr the stahility of the coating was lowered and some electrochemical corrosion took place.
The coatings of Examples I and II were tested at different current densities, and it was found that the oxygen evolution faraday efficiency decreased with in-- creasing current density up to a~out 2 KA/m , then remained sta~le above 2 KA/m .
,.:
PERCHLOR~TE PRODUCTION.
TECHNICAL FIELD
The invention relates to electrodes for use in electxol~tic processes, of the type comprising an electrically~conductive and corrosion-resistant sub-strate having an electrocatalytically-active surface coating, and to electrolytic processes using such electrodes, especially (~ut not exclusively) as anodes for the production of chlorates, perchlorates and other persalts and percompounds including organic peroxyacids.
BACKGROUND ART
For tile pxoduction of perchlorate, various anode materials have ~een ~lsed com~ercially, including smooth massive platinum, platinized t~tanium or tantalum (despite a tendency to produce excess oxygen) and lead dioxide coated on titanium or graphite, althou~h t~ese lead dioxide anodes have a high overvoltage and wear rapidly, Some proposals have already been made to con~ine platinum group metals and tin dioxide in electrode coatin~ materials. For example, U.S. Patent Specifica-tion 3,701,724 mentioned an anode for chlorine - production having a coating consisting essentially of ';
.. ~
~L29~3~9 1 a minor amount o~ a platinum group metal and/or platinum group metal oxides with a major amount of Sn02, Sbz05, Sb203 or Ge02 and mixtures thereof. However, the claims and examples of this patent are directed solely to such coatings containing platinum group metal oxides and there is no enabling disclosure of a coating containing a platinum group metal. Also, IJ.S. Patent Sp~cification - 3,882,002 proposed an anode for c,llorine production havin~ a valve metal substrate coated with an intermediate layer of tin dioxide which ~as covered with an outer la~er of a platinum group metal or oxide thereof. Neither of these proposals was directed to impro~ing electrolytic performance in the production of percompounds.
DISCLO~UR~ OF INVENTION
An object of the invention therefore is to provide an improved electrode suitable for use as an anode for the production of perchlorates and other persalts, but which may also be used in other applications, such as chlorate production.
2Q According to a main aspect of the invention, an electrode comprises an electrically-conductive corrosion-resistant substrate having an electrocatalytic coating and is characterized in -that the coating contains a mixture of at least one platinum group metal and tin ~`
dioxide dis~ersed in one another throughout the coating in the ratio of 8.5:1 to 3:2 by weight of the platinum group metals to the tin (as metal) of the tin dioxide.
The platinum group metal/tin dioxide coating may also contain a sta~ilizer/binder, for example a compound such as titanium dioxide r zirconium dioxide or s~licon dioxide. Additionally, the coating may include a filler, e.g. particles or fibres of an inert material such as silica or alumina, particles of titanium, or ~9~
1 z~rconium silicate. Furthermoxe, the coating may also contain, e.g, as ~ dopant the tin dioxide in a quantity up to about 30~ b~ welyht ~as metal) of the tin dioxide, of at least one additional metal or oxide of zinc, cadmium, arsenic, antimony, bismuth, selenium and tellurium.
Sucn stabilizers or binders, ~illers and dopants generally do not account for more tnan 70% of the total weight of the coating, usually far less. In the case of antimony trioxide or bismuth trioxide as dopant, the preferred amount corre$ponds to a ratio expressed as parts by weight of Sb~Bi:Sn ~as metal) of at most ahout 1:4 to about l:lO or even as low as 1:100.
The platinum group metals are ruthenium, rihodium/ palladium, osmium, iridium and platinum.
Platinum is the preferred platinum group metal in the coating, when a single metal is present, especially in anodes for perchlorate production. However, it is understood that alloys such as platinum-iridium and platinum-rhodium, also are useful for other applications.
An allo~ of platinum-palladium containing up to 20%
palladium by weight of the alloy has given very satis-factory results for perchlorate production. Also, in some instances, it may be advantageous to alloy the platinum group metal(s) with one or more non-platinum group metals, for example an alloy or an intermetallic compound witn one of the valve metals titanium, ~irconium, hafnium~ vanadium, niobium and tantalum, or with another transition metal, for example a metal such as tungsten, manganese or cobalt.
The substrate may consist of any of the afore-mentioned valve metals or alloys thereof, porous sintered titanium being preferred. However, other electrically-conductive and corrosion-resistant substrates may be used, such as expanded graphite.
The platinum grou~ metal(s) and tin dioxide 1 with possible additional dopants, such as antimon~
trioxide or bismuth trio~ide, may be co-deposited chemically from solutions of appropriate salts ~lhlch are painted, sprayed or otherwise applied on the substrate and then subjected to heat treatment, this process being repeated until a suffi~iently thick layer has been built up.
Alternatively, thin layers of different components te.g. alternate platinum or Pt/Pd alloy ~0 layers and layers of pure or doped tin dioxide) ~an be built up in such a way that the components are effectively mixed and dis~ersed in one another through-out the coating, possibly witll diffusion between the layers, in contrast to the known prior art coatin~s such as that of U. S. Patent Specification 3,882,002, in which the tin dioxide was applied as a separate intermediate layer covered by a platinum group metal.
Using this procedure of applying alternate layers, it is possible to deposit thin layers of platinum galvanically, which is advantageous, because gal-vanically-deposited platinum has a lower oxygen evolution potential than chemi-deposited platinumu The platinum-group metal or alloy/-tin dioxide layer may be applied directly to the substrate, or to an intermediate layer, e.g. of co-deposited tin and antimony oxides or tin and bismuth oxides, or to inter-mediate layers consisting of one or more platinum group metals or their oxides, mixtures or mixed crystals of platinum group metals and valve metal oxides, inter-metallics of platinum group metals and non-platinum group metals, and so for-tn.
In a preferred embodiment, the coating comprises 4Q to 85 parts by weight of platinum, 0 to 20 parts by wei~ht of palladium and 15 to 40 parts by weight (as Sn metal~ of tin dioxide on a titanium, tantalum or . .
` ~29~
1 titanium~tantalum alloy substrate. This emBodiment of an electrode o~ the inventionJ ~hen used as anode for perchlorate or persulphate production, has been found to have selective properties favouring the persalt production while hindering oxygen evolution. The platinum metal acts as a catalyst ~or persalt production.
The tin dioxide acts as an oxygen evolution inhibitor by blocking perox~de decomposition, which can be reyarded as the intermediate step of the un~anted oxygen evolution reaction. Finall~, ~he palladium acts as a diluent for the relatively more expensive platinum, without adversely affecting the ox~gen inhibition effect of the tin dioxide.
Another aspect of the 'invention is a process for the production of chlorates, perchlorates and other percompounds, e.y. persul~hates, which is characterised by using as anode an electrode according to the invention, as defined above.
BRIEF DESCRIpTION OF DRAWINGS
In the accompanying drawings:
Fig. 1 shows a graph of the faraday efficiency of oxygen evolution as ordinate plotted against the tin content of the electrode coating as abscissa, the electrode being that described below in detail in Example I;
Fig. 2 shows a graph of the faraday efficiency of oxygen evolution as ordinate plotted against the palladium content of the electrode coating as abscissa, the electrode being that described below in detail in Example II.
BEST MODES FOR CARRXING OUT HE INVENTION
The following Examples are given to illustrate - , , ~ . , , ~ , 1 the invention, E~AMPLE I
Titanium coupons measurin~ 10 x 10 x 1 mm were sandblasted and etched in 20% hydrochloric acid and were thoroughly washed in water. The coupons were then coated with an aqueous solution of chlorides of platinum and tin in different weight ratios~ dried at 95 to 100C
and then heated at 450C for 15 minutes in an oven ~7ith forc d air ventilation. The procedure was repeated five times and tlle coupons were given a final heat treatment at 450C for 60 minutes. The coatings so produced con-tained SnQ2 and platinum metal dispersed in one another.
The coated coupons were tested as anodes for the production of sodium perchlorate by the electroly-sis of a solution consisting of lOOg/l NaC103, 400g/1 NaC104 and 5g/1 Na2CrO4 at 30C using a stainless stPel cathode and a current densit~ of 2KA/m . Sodium chlorate was supplied and sodium perchlorate removed to maintain the concentrations in the electrolyte at a steady state.
2Q The faraday efficiency of the oxygen evolution reaction(i.e. the unwanted side reaction in perchlorate production) was measured as a function of the percentage by weight of ~in (as metal) in the mixe'd Pt-SnO2 coating. The results obtained are shown in Fig. 1, from which it can be seen that there is an optimum oxygen-inhibition effect for a tin content in the range of about 25%~35% of the total weight of tin and platinum metals, and a very appreciable inhibition of oxygen evolution for a tin content in the larger ran~e from about 15% to about 40%.
EXi~MPLE_II
Titanium coupons were coated as in Example I, but using various coating solutions containin~ platinum, .
~z~
1 palladium and tin chlorides, to produce mixed Pt~Pd~SnO2 coatings having compositions as fol low5:
.
Coatins Composition (% wei~ht of metal) Pt ¦ Pd ~ SnO2 _ . .. ~
0 ~ 30 j 30 ! 30 ?0 , 30 ' 25 ' 30 These coupons were tested as anodes for perchlorate production under the same conditions as used in Example I~ The faraday efficiency of the unwanted lS oxygen evolution reaction was measured as a function of the palladium metai content, and the results are shown in Fig. 2. This graph shows that, for a palladium content up to 20%~ the faraday efficiency remained low, i.e. the palladium did not.adversely affect the performance of the coating to inhibit oxygen evolution. However, above the critical Pd content of 20%~ the faraday efficiency abruptly increasedr the stahility of the coating was lowered and some electrochemical corrosion took place.
The coatings of Examples I and II were tested at different current densities, and it was found that the oxygen evolution faraday efficiency decreased with in-- creasing current density up to a~out 2 KA/m , then remained sta~le above 2 KA/m .
,.:
Claims (6)
1. An electrode for use in electrolytic processes, comprising an electrically-conductive corrosion-resistant substrate having an electro-catalytic coating, characterized in that the coating comprises a mixture of at least one platinum group metal and tin dioxide dispersed in one another throughout the coating in the ratio of from 8.5:1 to 3:2 by weight of the platinum group metal(s) to the tin of the tin dioxide.
2. The electrode of claim 1, characterized in that the platinum group metal is platinum.
3. The electrode of claim 1, characterised in that the coating comprises 40 to 85 parts by weight of platinum, 0 to 20 parts by weight of palladium and 15 to 40 parts by weight of tin.
4. The electrode of claim 1, 2 or 3, characterized in that the coating also comprises at least one additional metal or oxide of zinc, cadmium, arsenic, antimony, bismuth, selenium and tellurium in a quantity up to 30%
by weight of the tin.
by weight of the tin.
5. The electrode of claim 1, 2 or 3, characterized in that the coating also comprises one or more oxides of antimony and/or bismuth in an amount of at most 1 part by weight of Sb/Bi to 4 parts by weight of Sn.
6. A process for the production of chlorates, perchlorates and other percompounds by electrolysis, characterized by using as anode an electrode as claimed in claim 1, 2 or 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1205278 | 1978-03-28 | ||
| GB12052/78 | 1978-03-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1129809A true CA1129809A (en) | 1982-08-17 |
Family
ID=9997561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA324,281A Expired CA1129809A (en) | 1978-03-28 | 1979-03-27 | Electrolysis electrode with coating of tin dioxide and platinum group metal |
Country Status (5)
| Country | Link |
|---|---|
| EP (2) | EP0004880B1 (en) |
| CA (1) | CA1129809A (en) |
| DE (1) | DE2965811D1 (en) |
| FI (1) | FI66919C (en) |
| WO (1) | WO1979000843A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5544514A (en) * | 1978-09-22 | 1980-03-28 | Permelec Electrode Ltd | Electrode for electrolysis and production thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3616445A (en) * | 1967-12-14 | 1971-10-26 | Electronor Corp | Titanium or tantalum base electrodes with applied titanium or tantalum oxide face activated with noble metals or noble metal oxides |
-
1979
- 1979-03-26 FI FI791004A patent/FI66919C/en not_active IP Right Cessation
- 1979-03-27 EP EP79100917A patent/EP0004880B1/en not_active Expired
- 1979-03-27 DE DE7979100917T patent/DE2965811D1/en not_active Expired
- 1979-03-27 CA CA324,281A patent/CA1129809A/en not_active Expired
- 1979-03-27 WO PCT/EP1979/000022 patent/WO1979000843A1/en unknown
- 1979-11-05 EP EP79900338A patent/EP0018970A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| FI66919B (en) | 1984-08-31 |
| EP0004880A1 (en) | 1979-10-31 |
| EP0004880B1 (en) | 1983-07-06 |
| FI66919C (en) | 1984-12-10 |
| DE2965811D1 (en) | 1983-08-11 |
| EP0018970A1 (en) | 1980-11-26 |
| WO1979000843A1 (en) | 1979-11-01 |
| FI791004A (en) | 1979-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0153586B1 (en) | Electrode for electrolysis | |
| EP0203982B1 (en) | Method for preparing an electrode and use thereof in electrochemical processes | |
| US4555317A (en) | Cathode for the electrolytic production of hydrogen and its use | |
| US4272354A (en) | Electrodes for electrolytic processes | |
| CA1213563A (en) | Electrocatalytic electrode | |
| EP0715002B1 (en) | Stable coating solutions for preparing electrocatalytic mixed oxide coatings on metal substrates or metal-coated conductive substrates, and a method for the preparation of dimensionally stable anodes using such solutions | |
| Spasojević et al. | Microstructure of new composite electrocatalyst and its anodic behavior for chlorine and oxygen evolution | |
| EP0004386B1 (en) | Electrodes for electrolytic processes, especially metal electrowinning | |
| DE69508689T2 (en) | Electrode for electrochemical processes and their use | |
| JPS622038B2 (en) | ||
| CA1129809A (en) | Electrolysis electrode with coating of tin dioxide and platinum group metal | |
| US4267025A (en) | Electrodes for electrolytic processes, especially perchlorate production | |
| US4072585A (en) | Valve metal electrode with valve metal oxide semi-conductive coating having a chlorine discharge catalyst in said coating | |
| KR101741401B1 (en) | Coating solution for electrochemical insoluble electrode and preparation method thereof | |
| GB1573297A (en) | Electrode manufacture | |
| CA2030669C (en) | Metal electrodes for electrochemical processes | |
| US4222842A (en) | Electrode for electrolysis | |
| US4010091A (en) | Novel electrode for electrolysis cell | |
| JP3236653B2 (en) | Electrode for electrolysis | |
| Krstajić et al. | A selective catalyst for titanium anodes | |
| Harrison et al. | Electrocatalysis and the oxygen evolution reaction | |
| Bagri | Evaluation of Coated Titanium Anodes | |
| CA2061390A1 (en) | Metal anodes for electrolytic acid solutions containing fluorides or fluoroanionic complexes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |