EP0008476A1 - Process for the electrolytic production of hydrogen in an alkaline medium - Google Patents
Process for the electrolytic production of hydrogen in an alkaline medium Download PDFInfo
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- EP0008476A1 EP0008476A1 EP79200445A EP79200445A EP0008476A1 EP 0008476 A1 EP0008476 A1 EP 0008476A1 EP 79200445 A EP79200445 A EP 79200445A EP 79200445 A EP79200445 A EP 79200445A EP 0008476 A1 EP0008476 A1 EP 0008476A1
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- 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
- C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
- C25B11/077—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound the compound being a non-noble metal oxide
- C25B11/0771—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound the compound being a non-noble metal oxide of the spinel type
Definitions
- the subject of the present invention is a process for the electrolytic production of hydrogen in an alkaline medium in which the hydrogen is released on the active surface of a cathode.
- electrolysis processes it is generally sought to reduce the potentials of electrochemical reactions at the electrodes to as low a value as possible. This is particularly the case in the electrolysis processes in which hydrogen gas is produced on the active surface of a cathode, such as the processes for the electrolysis of water, aqueous solutions of hydrochloric acid and aqueous solutions of sodium chloride.
- the cathodes used until now in practice for the electrolysis of water or sodium chloride have generally consisted of plates or lattices of mild steel.
- the present invention aims to produce hydrogen in an alkaline medium by release on the surface of cathodes whose manufacture does not have the drawbacks of that of the cathodes described above and which have properties, and in particular an overvoltage on release of hydrogen, as favorable as those of the aforementioned cathodes.
- the cathodes used according to the invention have a particularly favorable service life.
- the invention therefore relates to a process for the electrolytic production of hydrogen in an alkaline medium in which the hydrogen is released in gaseous form at the active surface of a cathode and in which a cathode is used whose active surface is consisting essentially of oxidized compounds of the spinel type.
- the oxidized compounds of the spinel type used according to the invention, are mineral compounds of general formula M II M III 2 O 4 , where M II denotes a bivalent metallic element or more bivalent metallic elements and M III denotes a trivalent metallic element or several trivalent metallic elements. These oxidized compounds generally adopt the crystallographic structure of spinel proper MgA1 2 0 4 .
- Oxidized spinel-type compounds have a crystal lattice characterized by a compact cubic assembly of 32 oxygen atoms; the distribution of the atoms of the metals M II and M III in the mesh is such that 8 metallic atoms are arranged in the centers of 8 tetrahedra whose vertices are occupied by 4 oxygen atoms and 16 other metallic atoms are arranged in the centers of 16 octahedra whose summits are occupied by 6 oxygen atoms. Oxidized spinel-type compounds can be divided into two distinct groups.
- the 8 metal atoms which occupy the centers of the 8 tetrahedra are all atoms of the bivalent metal M II , the other 16 metal atoms being all atoms of the trivalent metal M III .
- the oxidized compounds of general formulas M II Al 2 O 4 (where M II denotes Mg, Mn, Fe, Co or Zn), MIICr204 (where M II denotes Mg, Mn, Fe, Co, Ni, Cu or Zn), ZnFe 2 0 4 , Mn304, and Co 3 0 4 all belong to this group of normal structure.
- oxidized compounds of normal structure oxidized compounds of reverse structure and oxidized compounds which have an intermediate structure between the normal structure and the reverse structure, such as, for example, the compound of formula general NiAl 2 O 4 , in which approximately 38 Z of aluminum atoms occupy the centers of tetrahedra.
- oxidized compounds which are very suitable for use according to the invention are those of general formula M II M III 2 O 4 where M II denotes a bivalent metal or several bivalent metals chosen from iron, zinc, manganese, nickel , cobalt, magnesium, cadmium and copper, and where M III denotes a trivalent metal or several trivalent metals chosen from aluminum, iron, chromium, manganese, vanadium, titanium, cobalt and gallium.
- oxidized compounds which contain a metal M III chosen from iron, chromium, manganese, nickel and cobalt, and, more particularly, compounds of general formula M II M III 2 O 4 , in which M and are identical, the metal being respectively in the bivalent and trivalent state.
- Magnetite, of general formula Fe 3 0 4 (or Fe II Fe III 2 O 4 ) is the compound leading to the best results when the cathodes are used in the presence of aqueous solutions of alkali metal hydroxide such as caustic detergents and caustic brines obtained by electrolysis of sodium chloride brines respectively in electrolysis cells with selective permeability membrane and in electrolysis cells with permeable diaphragm.
- membrane with selective permeability is understood to mean a thin, non-porous separator, separating the anodes from the cathodes and comprising an ion-exchange material.
- membranes with selective permeability suitable for brine electrolysis cells, include cationic membranes containing SO 3 groups and resulting from the copolymerization of tetrafluoroethylene and sulfonated perfluorvinyl ether, such as the membranes known under the name NAFION and sold by EI du Pont de Nemours & Co.
- diaphragm is meant a partition permeable to the electrolyte, made of an inert material, separating the anodes from the cathodes.
- known diaphragms include asbestos diaphragms, such as those described in United States patents 1 855 497, of May 7, 1928, of Stuart and Belgian 773 918 of October 14, 1971, in the name of the Applicant, porous sheets formed from a mixture of asbestos and a polyelectrolyte such as those described and claimed in Luxembourg patent 74 835 of April 26, 1976, in the name of the Applicant and porous polytetrafluoroethylene sheets, such as those described in Belgian patents 794,889 of February 2, 1973, 817,675, 817,676 and 817,677 of July 15, 1974, in the name of Imperial Chemical Industries Limited.
- the active surface of the cathodes used according to the invention may contain, in addition to oxidized compounds of the spinel type, foreign substances, for example in trace amounts, provided that these do not affect the properties of the oxidized compounds which are essential for the process according to the invention.
- cathodes used according to the invention can for example consist of solid blocks obtained by sintering a powder of the oxidized compound.
- a cathode consisting of a metal support, for example a metal plate, carrying the oxidized compound on at least part of its surface.
- the metal support can be of any metal or alloy resistant to the chemical and / or thermal conditions to which the cathode is subjected.
- the metal support advantageously consists of a steel plate, generally a plate openwork.
- the perforated plate may for example have a substantially planar profile in the case of a cathode intended to equip a cell of the type of those described, by way of example, in French patents 2,164,623 of December 12, 1972 and 2,230,411 of March 27, 1974, in the name of the Claimant.
- the perforated plate may have a corrugated profile in the case where the cathode is intended for an electrolysis cell of the type of those described, for example, in French patents 2,223,083 of March 28, 1973 and 2 248,335 of October 14, 1974, in the name of the Claimant.
- any technique known per se can be used to form or apply the oxidized compound to the metal support.
- a compound of general formula M 3 0 4 such as magnetite
- a powder of the oxidized compound in a suitable liquid containing a binder and apply one or more layers of the liquid suspension thus obtained to the support, for example by brushing, soaking or spraying, then optionally heating, thereafter, the coated support to melt the binder and coat the particles of the oxidized compound.
- the oxidized compound can be directly sprayed in the finely divided state into the plasma jet, in an inert atmosphere such as an argon atmosphere.
- the metal or metals used in the composition of the oxidized compound are projected, in the finely divided state, into a plasma jet in an inert atmosphere (for example argon), then the support thus coated is heated in a controlled oxidizing atmosphere to form the oxidized compound.
- an inert atmosphere for example argon
- the layer of the oxidized compound on the metal support generally has a thickness sufficient to resist abrasion wear in contact with the hydrogen gas and the electrolytes which circulate in contact with it during the electrolysis.
- the thickness of the layer of the oxidized compound on the metal support is at least 0.5 microns, preferably at least 5 microns. In the case where the layer is obtained by metallic projection in a plasma jet, as described above, good results are obtained with a thickness of the order of about 100 microns.
- the invention finds a particularly interesting application in cells with a permeable diaphragm and a membrane with selective permeability for the electrolysis of sodium chloride brines, such as those described, by way of example, in French patents 2,164,623 of the December 12, 1972, 2,223,083 of March 28, 1973, 2,230,411 of March 27, 1974, 2,248,335 of October 14, 1974 and in French patent application 77.11,370 of April 12, 1977, all in the name of the Applicant.
- an aqueous brine containing 255 g of sodium chloride per kg was electrolysed in a laboratory cell with vertical electrodes, separated by an asbestos diaphragm.
- the cylindrical cell included an anode formed of a circular titanium plate, pierced with vertical slits and coated with an active material of mixed crystals, consisting of 50% by weight of ruthenium dioxide and 50% by weight of titanium dioxide.
- the cathode consisted of a circular metallic lattice structure, the shape of which was identical in each example, but the constitution of which varied from one example to another.
- each electrode of the cell was 113 cm 2 , and the distance between the anode and the cathode was fixed at 5 mm.
- the diaphragm was applied to the face of the cathode, oriented towards the anode from a suspension of asbestos in a caustic brine, then heated for 16 hours at 90 ° C., applying the technique described in the application for Luxembourg patent 77.996 of August 19, 1977, in the name of the Applicant.
- the grammage of the resulting diaphragm was 1.3 kg / m 2 of cathode.
- the abovementioned brine was electrolysed in the cell, at 85 ° C., at a current density of 2 kA per square meter of anode, and the flow rate of brine introduced into the cell was adjusted.
- anode chamber so that the caustic brine leaving the cathode chamber contains approximately 100 g of sodium hydroxide and 140 g of sodium chloride per kg.
- the potential of the cathode was periodically measured, using the Luggin capillary measurement method, connected to a saturated calomel reference electrode (ECS) (Modern Electrochemistry, Bockris and Reddy, Plenum Press, 1970, vol.2 , p. 890 and 891).
- ECS saturated calomel reference electrode
- the cathode consisted of a mild steel mesh which was successively pickled using hydrochloric acid passivated with formalin, then heated to 750 ° C, in contact with an oxidizing flame produced by a laboratory bunsen burner, supplied with gas from the city of Brussels. The treatment was continued for a sufficient time to form on the surface of the steel lattice, a layer of magnetite approximately 10 microns thick.
- the cathode used consisted of a mild steel lattice, identical to that of the test of Example 1, which was successively pickled with hydrochloric acid passivated with formalin, then coated with a layer of magnetite by spraying a magnetite powder into a plasma jet, in an inert atmosphere.
- the mean grain diameter of the magnetite powder was approximately 8 microns, and the quantity of magnetite used was adjusted to obtain a coating of magnetite of approximately 250 microns on the cathode.
- a mild steel mesh identical to that of the preceding examples, pickled with passive hydrochloric acid with formalin, was used to manufacture the cathode.
- the pickled lattice was then coated with ten successive layers of mixed crystals of nickel oxide and cobalt oxide, having the structure of spinels, of general formula NiCo 2 0 4 .
- the mesh previously heated to 250 ° C., was immersed in a solution 0.1 molar of nickel nitrate and 0.2 molar of cobalt nitrate in butanol, then heated in air for 10 minutes at 250 ° C. After the application of the tenth layer of the coating, the coated mesh was heated in air for 16 hours at 350 ° C, then cooled to room temperature.
- a cathode prior to the invention consisting of a mild steel lattice, identical to that of Examples 1 and 2, and which was only pickled by treatment with hydrochloric acid passivated with formalin, then mounted as is in the cell.
- Table IV shows the evolution of the cathode potential during electrolysis.
Abstract
Description
La présente invention a pour objet un procédé pour la production électrolytique d'hydrogène en milieu alcalin dans lequel l'hydrogène se dégage à la surface active d'une cathode.The subject of the present invention is a process for the electrolytic production of hydrogen in an alkaline medium in which the hydrogen is released on the active surface of a cathode.
Dans les procédés d'électrolyse, on cherche généralement à réduire jusqu'à une valeur aussi faible que possible les potentiels des réactions électrochimiques aux électrodes. C'est particulièrement le cas dans les procédés d'électrolyse dans lesquels on produit de l'hydrogène gazeux à la surface active d'une cathode, tels que les procédés d'électrolyse de l'eau, de solutions aqueuses d'acide chlorhydrique et de solutions aqueuses de chlorure de sodium.In electrolysis processes, it is generally sought to reduce the potentials of electrochemical reactions at the electrodes to as low a value as possible. This is particularly the case in the electrolysis processes in which hydrogen gas is produced on the active surface of a cathode, such as the processes for the electrolysis of water, aqueous solutions of hydrochloric acid and aqueous solutions of sodium chloride.
Les cathodes utilisées jusqu'à présent en pratique pour l'électrolyse de l'eau ou du chlorure de sodium ont généralement consisté en plaques ou treillis d'acier doux.The cathodes used until now in practice for the electrolysis of water or sodium chloride have generally consisted of plates or lattices of mild steel.
Ainsi, dans la demande de brevet allemand 2 734 879 déposée le 3 août 1977 au nom de l'Etat d'Israël et publiée le 13 avril 1978, on propose de constituer des électrodes en des matériaux catalysant la décomposition du peroxyde d'hydrogène, qui consistent en des oxydes mixtes ayant la structure des spinelles et contenant du bore. On y signale que de tels matériaux peuvent aussi convenir pour la production électrolytique d'hydrogène gazeux en milieu alcalin.Thus, in the German patent application 2 734 879 filed on August 3, 1977 in the name of the State of Israel and published on April 13, 1978, it is proposed to constitute electrodes in materials catalyzing the decomposition of hydrogen peroxide, which consist of mixed oxides having the structure of spinels and containing boron. It indicates that such materials may also be suitable for the electrolytic production of hydrogen gas in an alkaline medium.
L'incorporation de bore dans de tels matériaux constitue une opération difficile et coûteuse, nécessitant un traitement à très haute température, généralement de l'ordre de 900°C. Les cathodes, surtout lorsqu'elles consistent en plaques minces ou en treillis, peuvent difficilement supporter des températures aussi élevées sans subir des déformations locales, nuisibles au bon fonctionnement des cellules d'électrolyse.The incorporation of boron into such materials constitutes a difficult and costly operation, requiring treatment at very high temperature, generally of the order of 900 ° C. Cathodes, especially when they consist of thin plates or lattices, can hardly withstand such high temperatures without undergoing local deformations, detrimental to the proper functioning of electrolysis cells.
La présente invention vise à produire de l'hydrogène en milieu alcalin par dégagement à la surface de cathodes dont la fabrication ne comporte pas les inconvénients de celle des cathodes décrites ci-dessus et qui présentent des propriétés, et notamment une surtension au dégagement d'hydrogène, aussi favorables que celles des cathodes précitées. De plus, les cathodes utilisées selon l'invention présentent une durée de service particulièrement favorable.The present invention aims to produce hydrogen in an alkaline medium by release on the surface of cathodes whose manufacture does not have the drawbacks of that of the cathodes described above and which have properties, and in particular an overvoltage on release of hydrogen, as favorable as those of the aforementioned cathodes. In addition, the cathodes used according to the invention have a particularly favorable service life.
L'invention concerne dès lors un procédé pour la production électrolytique d'hydrogène en milieu alcalin dans lequel l'hydrogène se dégage sous forme gazeuse à la surface active d'une cathode et dans lequel on met en oeuvre une cathode dont la surface active est constituée essentiellement de composés oxydés du type des spinelles.The invention therefore relates to a process for the electrolytic production of hydrogen in an alkaline medium in which the hydrogen is released in gaseous form at the active surface of a cathode and in which a cathode is used whose active surface is consisting essentially of oxidized compounds of the spinel type.
On a constaté, en effet, qu'utilisés pour constituer la surface active d'une cathode pour la production électrolytique d'hydrogène en milieu alcalin, les composés oxydés du type des spinelles qui sont exempts de bore, présentent, toutes autres choses étant égales, une surtension au dégagement d'hydrogène au moins comparable et même, parfois, inférieure à celle de ces mêmes composés oxydés contenant du bore proposés dans la demande de brevet allemand 2 734 879 susdite.It has been found, in fact, that used to constitute the active surface of a cathode for the electrolytic production of hydrogen in an alkaline medium, the oxidized compounds of the spinel type which are free of boron, present, all other things being equal , an overvoltage at hydrogen evolution at least comparable and even, sometimes, lower than that of these same oxidized compounds containing boron proposed in the aforementioned German patent application 2 734 879.
En conformité avec la définition qui en est généralement donnée dans la littérature (Structural Inorganic Chemistry - A.F. Wells - Oxford University Press - 1962 -. pages 487 à 490 ; Crystal Structures of Minerals - Bragg et Claringbull - Bell and Sons Ltd - 1965 - pages 102 à 106) les composés oxydés du type des spinelles, utilisés selon l'invention, sont des composés minéraux de formule générale MIIMIII 2O4, où MII désigne un élément métallique bivalent ou plusieurs éléments métalliques bivalents et MIII désigne un élément métallique trivalent ou plusieurs éléments métalliques trivalents. Ces composés oxydés adoptent généralement la structure cristallographique du spinelle proprement dit MgA1204. Ces composés oxydés du type des spinelles présentent une maille cristalline caractérisée par un assemblage cubique compact de 32 atomes d'oxygène ; la répartition des atomes des métaux MII et MIII dans la maille est telle que 8 atomes métalliques sont disposés aux centres de 8 tétraèdres dont les sommets sont occupés par 4 atomes d'oxygène et 16 autres atomes métalliques sont disposés aux centres de 16 octaèdres dont les sommets sont occupés par 6 atomes d'oxygène. Les composés oxydés du type des spinelles peuvent être répartis en deux groupes distincts.In accordance with the definition which is generally given in the literature (Structural Inorganic Chemistry - AF Wells - Oxford University Press - 1962 -. Pages 487 to 490; Crystal Structures of Minerals - Bragg and Claringbull - Bell and Sons Ltd - 1965 - pages 102 to 106) the oxidized compounds of the spinel type, used according to the invention, are mineral compounds of general formula M II M III 2 O 4 , where M II denotes a bivalent metallic element or more bivalent metallic elements and M III denotes a trivalent metallic element or several trivalent metallic elements. These oxidized compounds generally adopt the crystallographic structure of spinel proper MgA1 2 0 4 . These oxidized spinel-type compounds have a crystal lattice characterized by a compact cubic assembly of 32 oxygen atoms; the distribution of the atoms of the metals M II and M III in the mesh is such that 8 metallic atoms are arranged in the centers of 8 tetrahedra whose vertices are occupied by 4 oxygen atoms and 16 other metallic atoms are arranged in the centers of 16 octahedra whose summits are occupied by 6 oxygen atoms. Oxidized spinel-type compounds can be divided into two distinct groups.
Dans l'un de ces groupes, appelé groupe de structure normale, les 8 atomes métalliques qui occupent les centres des 8 tétraèdres sont tous des atomes du métal bivalent MII, les 16 autres atomes métalliques étant tous des atomes du métal trivalent MIII. Les composés oxydés de formules générales MIIAl2O4 (où MII désigne Mg, Mn, Fe, Co ou Zn), MIICr204 (où MII désigne Mg, Mn, Fe, Co, Ni, Cu ou Zn), ZnFe204, Mn304, et Co304 appartiennent tous à ce groupe de structure normale.In one of these groups, called the normal structure group, the 8 metal atoms which occupy the centers of the 8 tetrahedra are all atoms of the bivalent metal M II , the other 16 metal atoms being all atoms of the trivalent metal M III . The oxidized compounds of general formulas M II Al 2 O 4 (where M II denotes Mg, Mn, Fe, Co or Zn), MIICr204 (where M II denotes Mg, Mn, Fe, Co, Ni, Cu or Zn), ZnFe 2 0 4 , Mn304, and Co 3 0 4 all belong to this group of normal structure.
Dans l'autre groupe appelé groupe de structure inverse, ce sont 8 atomes de métal trivalent MIII, qui occupent les centres des huit tétraèdres, les centres des 16 octaèdres étant occupés par moitié par les 8 atomes restants de métal trivalent MIII et, par moitié, par les 8 atomes de métal bivalent MII. Les composés de formules générales MIIFe2O4, où MII désigne un métal bivalent choisi parmi Mg, Fe, Co, Ni et Cu appartiennent généralement à ce groupe de structure inverse.In the other group called reverse structure group, these are 8 atoms of trivalent metal M III , which occupy the centers of the eight tetrahedra, the centers of the 16 octahedra being half occupied by the 8 remaining atoms of trivalent metal M III and, by half, by the 8 atoms of bivalent metal M II . The compounds of general formulas M II Fe 2 O 4 , where M II denotes a bivalent metal chosen from Mg, Fe, Co, Ni and Cu generally belong to this group of reverse structure.
Selon l'invention, on peut utiliser indifféremment des composés oxydés de structure normale, des composés oxydés de structure inverse et des composés oxydés qui présentent une structure intermédiaire entre la structure normale et la structure inverse, tels que, par exemple, le composé de formule générale NiAl2O4, dans lequel 38 Z environ des atomes d'aluminium occupent les centres de tétraèdres.According to the invention, it is possible to use either oxidized compounds of normal structure, oxidized compounds of reverse structure and oxidized compounds which have an intermediate structure between the normal structure and the reverse structure, such as, for example, the compound of formula general NiAl 2 O 4 , in which approximately 38 Z of aluminum atoms occupy the centers of tetrahedra.
Des exemples de composés oxydés convenant bien pour être utilisés selon l'invention sont ceux de formule générale MIIMIII 2O4 où MII désigne un métal bivalent ou plusieurs métaux bivalents choisis parmi le fer, le zinc, le manganèse, le nickel, le cobalt, le magnésium, le cadmium et le cuivre, et où MIII désigne un métal trivalent ou plusieurs métaux trivalents choisis parmi l'aluminium, le fer, le chrome, le manganèse, le vanadium, le titane, le cobalt et le gallium.Examples of oxidized compounds which are very suitable for use according to the invention are those of general formula M II M III 2 O 4 where M II denotes a bivalent metal or several bivalent metals chosen from iron, zinc, manganese, nickel , cobalt, magnesium, cadmium and copper, and where M III denotes a trivalent metal or several trivalent metals chosen from aluminum, iron, chromium, manganese, vanadium, titanium, cobalt and gallium.
Selon l'invention, on préfère utiliser des composés oxydés qui contiennent un métal MIII choisi parmi le fer, le chrome, le manganèse, le nickel et le cobalt, et, plus particulièrement, des composés de formule générale MIIMIII 2O4, dans lesquels M et sont identiques, le métal se trouvant respectivement à l'état bivalent et trivalent. La magnétite, de formule générale Fe304 (ou FeIIFeIII 2O4) est le composé conduisant aux meilleurs résultats lorsque les cathodes sont utilisées en présence de solutions aqueuses d'hydroxyde de métal alcalin telles que les lessives caustiques et les saumures caustiques obtenues par électrolyse de saumures de chlorure de sodium respectivement en cellules d'électrolyse à membrane à perméabilité sélective et en cellules d'électrolyse à diaphragme perméable.According to the invention, it is preferred to use oxidized compounds which contain a metal M III chosen from iron, chromium, manganese, nickel and cobalt, and, more particularly, compounds of general formula M II M III 2 O 4 , in which M and are identical, the metal being respectively in the bivalent and trivalent state. Magnetite, of general formula Fe 3 0 4 (or Fe II Fe III 2 O 4 ) is the compound leading to the best results when the cathodes are used in the presence of aqueous solutions of alkali metal hydroxide such as caustic detergents and caustic brines obtained by electrolysis of sodium chloride brines respectively in electrolysis cells with selective permeability membrane and in electrolysis cells with permeable diaphragm.
On entend par membrane à perméabilité sélective, un séparateur mince, non poreux, séparant les anodes des cathodes et comprenant une matière échangeuse d'ions. Des exemples de membranes à perméabilité sélective, convenant pour des cellules d'électrolyse de saumure, comprennent des membranes cationiques contenant des groupes S03 et résultant de la copolymérisation du tétrafluoréthylène et du perfluor- vinyléther sulfoné, telles que les membranes connues sous le nom NAFION et vendues par E.I. du Pont de Nemours & Co.The term “membrane with selective permeability” is understood to mean a thin, non-porous separator, separating the anodes from the cathodes and comprising an ion-exchange material. Examples of membranes with selective permeability, suitable for brine electrolysis cells, include cationic membranes containing SO 3 groups and resulting from the copolymerization of tetrafluoroethylene and sulfonated perfluorvinyl ether, such as the membranes known under the name NAFION and sold by EI du Pont de Nemours & Co.
On entend par diaphragme, une cloison perméable à l'électrolyte, en un matériau inerte, séparant les anodes des cathodes. Des exemples de diaphragmes connus comprennent des diaphragmes en amiante, tels que ceux décrits dans les brevets Etats-Unis 1 855 497, du 7 mai 1928, de Stuart et belge 773 918 du 14 octobre 1971, au nom de la Demanderesse, des feuilles poreuses formées d'un mélange d'amiante et d'un poly- électrolyte telles que celles décrites et revendiquées dans le brevet luxembourgeois 74 835 du 26 avril 1976, au nom de la Demanderesse et des feuilles poreuses en polytétrafluoréthylène, telles que celles décrites dans les brevets belges 794 889 du 2 février 1973, 817 675, 817 676 et 817 677 du 15 juillet 1974, au nom de Impérial Chemical Industries Limited.By diaphragm is meant a partition permeable to the electrolyte, made of an inert material, separating the anodes from the cathodes. Examples of known diaphragms include asbestos diaphragms, such as those described in United States patents 1 855 497, of May 7, 1928, of Stuart and Belgian 773 918 of October 14, 1971, in the name of the Applicant, porous sheets formed from a mixture of asbestos and a polyelectrolyte such as those described and claimed in Luxembourg patent 74 835 of April 26, 1976, in the name of the Applicant and porous polytetrafluoroethylene sheets, such as those described in Belgian patents 794,889 of February 2, 1973, 817,675, 817,676 and 817,677 of July 15, 1974, in the name of Imperial Chemical Industries Limited.
La surface active des cathodes utilisées selon l'invention peut contenir en plus des composés oxydés du type des spinelles, des substances étrangères, par exemple à l'état de traces, pour autant que celles-ci n'affectent pas les propriétés des composés oxydés qui sont essentielles pour le procédé selon l'invention.The active surface of the cathodes used according to the invention may contain, in addition to oxidized compounds of the spinel type, foreign substances, for example in trace amounts, provided that these do not affect the properties of the oxidized compounds which are essential for the process according to the invention.
On peut faire usage de toute technique connue en soi pour fabriquer les cathodes utilisées selon l'invention. Celles-ci peuvent par exemple consister en blocs massifs obtenus par frittage d'une poudre du composé oxydé.Any technique known per se can be used to manufacture the cathodes used according to the invention. These can for example consist of solid blocks obtained by sintering a powder of the oxidized compound.
Dans une forme de réalisation particulière, on peut utiliser une cathode consistant en un support métallique, par exemple une plaque métallique, portant le composé oxydé sur une partie au moins de sa surface. Le support métallique peut être en n'importe quel métal ou alliage résistant aux conditions chimiques et/ou thermiques auxquelles la cathode est soumise. Dans le cas particulier où la cathode est destinée à équiper une cellule à diaphragme perméable ou à membrane à perméabilité sélective pour l'électrolyse de solutions aqueuses d'halogénures de métaux alcalins, le support métallique consiste avantageusement en une plaque en acier, généralement une plaque ajourée. La plaque ajourée peut par exemple avoir un profil sensiblement plan dans le cas d'une cathode destinée à équiper une cellule du type de celles décrites, à titre d'exemples, dans les brevets français 2 164 623 du 12 décembre 1972 et 2 230 411 du 27 mars 1974, au nom de la Demanderesse.In a particular embodiment, it is possible to use a cathode consisting of a metal support, for example a metal plate, carrying the oxidized compound on at least part of its surface. The metal support can be of any metal or alloy resistant to the chemical and / or thermal conditions to which the cathode is subjected. In the particular case where the cathode is intended to equip a cell with a permeable diaphragm or a membrane with selective permeability for the electrolysis of aqueous solutions of alkali metal halides, the metal support advantageously consists of a steel plate, generally a plate openwork. The perforated plate may for example have a substantially planar profile in the case of a cathode intended to equip a cell of the type of those described, by way of example, in French patents 2,164,623 of December 12, 1972 and 2,230,411 of March 27, 1974, in the name of the Claimant.
En variante, la plaque perforée peut avoir un profil ondulé dans le cas où la cathode est destinée à une cellule d'électrolyse du type de celles décrites, à titre d'exemple, dans les brevets français 2 223 083 du 28 mars 1973 et 2 248 335 du 14 octobre 1974, au nom de la Demanderesse.As a variant, the perforated plate may have a corrugated profile in the case where the cathode is intended for an electrolysis cell of the type of those described, for example, in French patents 2,223,083 of March 28, 1973 and 2 248,335 of October 14, 1974, in the name of the Claimant.
On peut faire usage de toute technique connue en soi pour former ou appliquer le composé oxydé sur le support métallique. Dans le cas d'un composé de formule générale M304, tel que la magnétite on peut utiliser un support en ce métal M et le chauffer superficiellement en atmosphère oxydante contrôlée, par exemple dans un four ou au contact d'une flamme oxydante.Any technique known per se can be used to form or apply the oxidized compound to the metal support. In the case of a compound of general formula M 3 0 4 , such as magnetite, it is possible to use a support of this metal M and to heat it superficially in a controlled oxidizing atmosphere, for example in an oven or in contact with an oxidizing flame. .
On peut aussi, en variante, disperser une poudre du composé oxydé dans un liquide approprié contenant un liant et appliquer une ou plusieurs couches de la suspension liquide ainsi obtenue sur le support, par exemple par badigeonnage, trempage ou pulvérisation, puis chauffer éventuellement, par la suite, le support enduit pour fondre le liant et en enrober les particules du composé oxydé.Alternatively, it is also possible to disperse a powder of the oxidized compound in a suitable liquid containing a binder and apply one or more layers of the liquid suspension thus obtained to the support, for example by brushing, soaking or spraying, then optionally heating, thereafter, the coated support to melt the binder and coat the particles of the oxidized compound.
On préfère toutefois appliquer le composé oxydé sur le support métallique par une technique de projection dans un jet de plasma. A cet effet, diverses variantes d'exécution sont possibles. On peut notamment projeter directement le composé oxydé à l'état finement divisé dans le jet de plasma, en atmosphère inerte telle qu'une atmosphère d'argon.However, it is preferred to apply the oxidized compound to the metal support by a technique of projection in a plasma jet. To this end, various execution variants are possible. In particular, the oxidized compound can be directly sprayed in the finely divided state into the plasma jet, in an inert atmosphere such as an argon atmosphere.
En variante, on peut aussi projeter le métal ou les métaux entrant dans la composition du composé oxydé, à l'état finement divisé dans un jet de plasma, en atmosphère oxydante contrôlée.As a variant, it is also possible to project the metal or metals entering into the composition of the oxidized compound, in the finely divided state in a plasma jet, in a controlled oxidizing atmosphere.
Selon une autre variante de la technique de projection par plasma, on projette le métal ou les métaux entrant dans la composition du composé oxydé, à l'état finement divisé dans un jet de plasma en atmosphère inerte (par exemple de l'argon), puis on chauffe le support ainsi revêtu en atmosphère oxydante contrôlée pour y former le composé oxydé.According to another variant of the plasma projection technique, the metal or metals used in the composition of the oxidized compound are projected, in the finely divided state, into a plasma jet in an inert atmosphere (for example argon), then the support thus coated is heated in a controlled oxidizing atmosphere to form the oxidized compound.
La couche du composé oxydé sur le support métallique possède en général une épaisseur suffisante pour résister à l'usure par abrasion au contact de l'hydrogène gazeux et des électrolytes qui circulent à son contact pendant l'électrolyse. D'une manière générale, il est souhaitable que l'épaisseur de la couche du composé oxydé sur le support métallique soit d'au moins 0,5 micron de préférence d'au moins 5 microns. Dans le cas où la couche est obtenue par projection métallique dans un jet de plasma, comme décrit plus haut, on obtient de bons résultats avec une épaisseur de l'ordre d'environ 100 microns.The layer of the oxidized compound on the metal support generally has a thickness sufficient to resist abrasion wear in contact with the hydrogen gas and the electrolytes which circulate in contact with it during the electrolysis. Generally, it is desirable that the thickness of the layer of the oxidized compound on the metal support is at least 0.5 microns, preferably at least 5 microns. In the case where the layer is obtained by metallic projection in a plasma jet, as described above, good results are obtained with a thickness of the order of about 100 microns.
L'invention trouve une application particulièrement intéressante dans les cellules à diaphragme perméable et à membrane à perméabilité sélective pour l'électrolyse de saumures de chlorure de sodium, telles que celles décrites, à titre d'exemple, dans les brevets français 2 164 623 du 12 décembre 1972, 2 223 083 du 28 mars 1973, 2 230 411 du 27 mars 1974, 2 248 335 du 14 octobre 1974 et dans la demande de brevet français 77.11 370 du 12 avril 1977, tous au nom de la Demanderesse.The invention finds a particularly interesting application in cells with a permeable diaphragm and a membrane with selective permeability for the electrolysis of sodium chloride brines, such as those described, by way of example, in French patents 2,164,623 of the December 12, 1972, 2,223,083 of March 28, 1973, 2,230,411 of March 27, 1974, 2,248,335 of October 14, 1974 and in French patent application 77.11,370 of April 12, 1977, all in the name of the Applicant.
L'intérêt de l'invention va ressortir de la description des exemples d'application suivants, qui sont donnés exclusivement à titre illustratif.The advantage of the invention will become apparent from the description of the following application examples, which are given exclusively by way of illustration.
Dans chacun des exemples qui vont suivre, on a procédé à l'électrolyse d'une saumure aqueuse contenant 255 g de chlorure de sodium par kg, dans une cellule de laboratoire à électrodes verticales, séparées par un diaphragme en amiante.In each of the following examples, an aqueous brine containing 255 g of sodium chloride per kg was electrolysed in a laboratory cell with vertical electrodes, separated by an asbestos diaphragm.
La cellule, de forme cylindrique, comprenait une anode formée d'une plaque circulaire en titane, percée de fentes verticales et revêtue d'un matériau actif de cristaux mixtes, constitués de 50 X en poids de bioxyde de ruthénium et 50 % en poids de bioxyde de titane.The cylindrical cell included an anode formed of a circular titanium plate, pierced with vertical slits and coated with an active material of mixed crystals, consisting of 50% by weight of ruthenium dioxide and 50% by weight of titanium dioxide.
La cathode a consisté en une structure métallique circulaire en treillis, dont la forme a été identique dans chaque exemple, mais dont la constitution a varié d'un exemple à l'autre.The cathode consisted of a circular metallic lattice structure, the shape of which was identical in each example, but the constitution of which varied from one example to another.
La surface globale de chaque électrode de la cellule était égale à 113 cm2, et la distance entre l'anode et la cathode a été fixée à 5 mm.The overall surface of each electrode of the cell was 113 cm 2 , and the distance between the anode and the cathode was fixed at 5 mm.
Le diaphragme a été appliqué sur la face de la cathode, orientée vers l'anode au départ d'une suspension d'amiante dans une saumure caustique, puis chauffé pendant 16 heures à 90 °C, en appliquant la technique décrite dans la demande de brevet luxembourgeois 77.996 du 19 août 1977, au nom de la Demanderesse. Le grammage du diaphragme résultant était de 1,3 kg/m2 de cathode.The diaphragm was applied to the face of the cathode, oriented towards the anode from a suspension of asbestos in a caustic brine, then heated for 16 hours at 90 ° C., applying the technique described in the application for Luxembourg patent 77.996 of August 19, 1977, in the name of the Applicant. The grammage of the resulting diaphragm was 1.3 kg / m 2 of cathode.
Dans chaque exemple, on a procédé à l'électrolyse de la saumure précitée dans la cellule, à 85°C, sous une densité de courant de 2 kA par mètre carré d'anode, et on a réglé le débit de saumure introduite dans la chambre anodique, pour que la saumure caustique sortant de la chambre cathodique contienne environ 100 g d'hydroxyde de sodium et 140 g de chlorure de sodium par kg. On a mesuré périodiquement le potentiel de la cathode, au moyen de la méthode de mesure au capillaire de Luggin, relié à une électrode de référence au calomel saturé (ECS) (Modern Electrochemistry, Bockris and Reddy, Plenum Press, 1970, vol.2, p. 890 et 891).In each example, the abovementioned brine was electrolysed in the cell, at 85 ° C., at a current density of 2 kA per square meter of anode, and the flow rate of brine introduced into the cell was adjusted. anode chamber, so that the caustic brine leaving the cathode chamber contains approximately 100 g of sodium hydroxide and 140 g of sodium chloride per kg. The potential of the cathode was periodically measured, using the Luggin capillary measurement method, connected to a saturated calomel reference electrode (ECS) (Modern Electrochemistry, Bockris and Reddy, Plenum Press, 1970, vol.2 , p. 890 and 891).
La cathode a consisté en un treillis en acier doux qui a successivement été décapé au moyen d'acide chlorhydrique passivé au formol, puis chauffé jusqu'à 750°C, au contact d'une flamme oxydante produite par un bec bunsen de laboratoire, alimenté en gaz de la ville de Bruxelles. Le traitement a été poursuivi pendant un temps suffisant pour former à la surface du treillis d'acier, une couche de magnétite de 10 microns d'épaisseur, environ.The cathode consisted of a mild steel mesh which was successively pickled using hydrochloric acid passivated with formalin, then heated to 750 ° C, in contact with an oxidizing flame produced by a laboratory bunsen burner, supplied with gas from the city of Brussels. The treatment was continued for a sufficient time to form on the surface of the steel lattice, a layer of magnetite approximately 10 microns thick.
On a consigné, au tableau I, l'évolution du potentiel cathodique de la cathode ainsi obtenue, pendant l'électrolyse.
Dans le présent essai, la cathode utilisée a consisté en un treillis en acier doux, identique à celui de l'essai de l'exemple 1, qui a été successivement décapé à l'acide chlorhydrique passivé au formol, puis revêtu d'une couche de magnétite par projection d'une poudre de magnétite dans un jet de plasma, en atmosphère inerte. Le diamètre moyen des grains de la poudre de magnétite était de 8 microns environ, et la quantité de magnétite mise en oeuvre a été réglée pour obtenir sur la cathode, un revêtement de magnétite de 250 microns environ.In the present test, the cathode used consisted of a mild steel lattice, identical to that of the test of Example 1, which was successively pickled with hydrochloric acid passivated with formalin, then coated with a layer of magnetite by spraying a magnetite powder into a plasma jet, in an inert atmosphere. The mean grain diameter of the magnetite powder was approximately 8 microns, and the quantity of magnetite used was adjusted to obtain a coating of magnetite of approximately 250 microns on the cathode.
On a mentionné au tableau II l'évolution du potentiel de la cathode pendant l'électrolyse.The evolution of the cathode potential during electrolysis has been mentioned in Table II.
Durée de l'électrolyse Potentiel cathodique (jours) (V/ECS)
- 3 -1,25
- 40 -1,25
- 70 -1,25
- 90 -1,25
- 3 -1.25
- 40 -1.25
- 70 -1.25
- 90 -1.25
Dans cet essai, on a utilisé, pour fabriquer la cathode, un treillis en acier doux, identique à celui des exemples précédents, décapé à l'acide chlorhydrique passive au formol. Le treillis décapé a ensuite été revêtu de dix couches successives de cristaux mixtes d'oxyde de nickel et d'oxyde de cobalt, ayant la structure des spinelles, de formule générale NiCo204. Pour appliquer chacune des couches, lé treillis, préalablement chauffé à 250°C, a été immergé dans une solution 0,1 molaire de nitrate de nickel et 0,2 molaire de nitrate de cobalt dans du butanol, puis chauffé à l'air pendant 10 minutes à 250°C. Après l'application de la dixième couche du revêtement, le treillis revêtu a été chauffé à l'air pendant 16 heures à 350°C, puis refroidi à température ambiante.In this test, a mild steel mesh, identical to that of the preceding examples, pickled with passive hydrochloric acid with formalin, was used to manufacture the cathode. The pickled lattice was then coated with ten successive layers of mixed crystals of nickel oxide and cobalt oxide, having the structure of spinels, of general formula NiCo 2 0 4 . To apply each of the layers, the mesh, previously heated to 250 ° C., was immersed in a solution 0.1 molar of nickel nitrate and 0.2 molar of cobalt nitrate in butanol, then heated in air for 10 minutes at 250 ° C. After the application of the tenth layer of the coating, the coated mesh was heated in air for 16 hours at 350 ° C, then cooled to room temperature.
On a consigné au tableau III l'évolution du potentiel de la cathode ainsi obtenue, pendant l'électrolyse.
A titre comparatif, on a utilisé une cathode antérieure à l'invention, constituée d'un treillis en acier doux, identique à celui des exemples 1 et 2, et qui a uniquement été décapé par traitement à l'acide chlorhydrique passivé au formol, puis monté tel quel dans la cellule.By way of comparison, a cathode prior to the invention was used, consisting of a mild steel lattice, identical to that of Examples 1 and 2, and which was only pickled by treatment with hydrochloric acid passivated with formalin, then mounted as is in the cell.
Le Tableau IV mentionne l'évolution du potentiel de la cathode pendant l'électrolyse.
Une comparaison des résultats des exemples 1, 2 et 3 (confor mes à l'invention) , avec ceux de l'exemple 4 (antérieur à l'invention) fait apparaître immédiatement le progrès apporté par l'invention en ce qui concerne le rendement énergétique des cellules d'électrolyse.A comparison of the results of Examples 1, 2 and 3 (in accordance with the invention) with those of Example 4 (prior to the invention) immediately shows the progress brought by the invention as regards the yield energy of electrolysis cells.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT79200445T ATE3653T1 (en) | 1978-08-24 | 1979-08-13 | ELECTROLYSIS PROCESS FOR THE PRODUCTION OF HYDROGEN IN AN ALKALINE MEDIUM. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7824757A FR2434213A1 (en) | 1978-08-24 | 1978-08-24 | PROCESS FOR THE ELECTROLYTIC PRODUCTION OF HYDROGEN IN AN ALKALINE MEDIUM |
| FR7824757 | 1978-08-24 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0008476A1 true EP0008476A1 (en) | 1980-03-05 |
| EP0008476B1 EP0008476B1 (en) | 1983-06-01 |
Family
ID=9212108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP79200445A Expired EP0008476B1 (en) | 1978-08-24 | 1979-08-13 | Process for the electrolytic production of hydrogen in an alkaline medium |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US4243497A (en) |
| EP (1) | EP0008476B1 (en) |
| JP (1) | JPS5531195A (en) |
| AT (1) | ATE3653T1 (en) |
| AU (1) | AU522946B2 (en) |
| BR (1) | BR7905329A (en) |
| CA (1) | CA1142129A (en) |
| DE (1) | DE2965571D1 (en) |
| ES (1) | ES483595A1 (en) |
| FI (1) | FI65283C (en) |
| FR (1) | FR2434213A1 (en) |
| NO (1) | NO153110C (en) |
| PT (1) | PT70103A (en) |
| ZA (1) | ZA794241B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2469013A1 (en) * | 1979-11-06 | 1981-05-08 | South African Inventions | ELECTROCHEMICAL ELEMENT, IN PARTICULAR A BATTERY CATHODE, AND ITS MANUFACTURING METHOD |
| US4411761A (en) * | 1980-06-28 | 1983-10-25 | Basf Aktiengesellschaft | Spinel-containing electrode and process for its production |
| EP0031948B1 (en) * | 1979-12-26 | 1986-10-15 | Asahi Kasei Kogyo Kabushiki Kaisha | A hydrogen-evolution electrode |
| FR2581082A1 (en) * | 1985-04-26 | 1986-10-31 | Int Fuel Cells Corp | METHOD OF USING ANODES CONTAINING A NICO2O4 CATALYST FOR THE ELECTROLYSIS OF POTASSIUM HYDROXIDE SOLUTIONS AND METHOD OF MANUFACTURING SUCH ANODES |
| CN1323853C (en) * | 2001-12-14 | 2007-07-04 | 株式会社寿 | Double clip head mechanical propelling pencil |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4410413A (en) * | 1981-10-05 | 1983-10-18 | Mpd Technology Corporation | Cathode for electrolytic production of hydrogen |
| US4445989A (en) * | 1982-08-11 | 1984-05-01 | The United States Of America As Represented By The Secretary Of The Army | Ceramic anodes for corrosion protection |
| CA1246494A (en) * | 1982-11-30 | 1988-12-13 | Hiroyuki Shiroki | Hydrogen-evolution electrode and a method of producing the same |
| US4546058A (en) * | 1984-12-12 | 1985-10-08 | Energy Research Corporation | Nickel electrode for alkaline batteries |
| JPS6286187A (en) * | 1985-10-09 | 1987-04-20 | Asahi Chem Ind Co Ltd | Electrode for generating hydrogen |
| WO1989001992A1 (en) * | 1987-09-02 | 1989-03-09 | Moltech Invent S.A. | A composite ceramic/metal material |
| US5205911A (en) * | 1990-11-13 | 1993-04-27 | Oxytech Systems, Inc. | Cathode restoration |
| US20090301868A1 (en) * | 2008-06-10 | 2009-12-10 | General Electric Company | Methods and systems for assembling electrolyzer stacks |
| US9045839B2 (en) * | 2008-06-10 | 2015-06-02 | General Electric Company | Methods and systems for in-situ electroplating of electrodes |
| US9657400B2 (en) * | 2008-06-10 | 2017-05-23 | General Electric Company | Electrolyzer assembly method and system |
| US8277620B2 (en) * | 2008-09-30 | 2012-10-02 | General Electric Company | Electrolyzer module forming method and system |
| US9080242B2 (en) * | 2008-09-30 | 2015-07-14 | General Electric Company | Pressurized electrolysis stack with thermal expansion capability |
| JP6221067B2 (en) * | 2013-12-03 | 2017-11-01 | パナソニックＩｐマネジメント株式会社 | Formic acid production apparatus and method |
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| US3329594A (en) * | 1964-12-08 | 1967-07-04 | Pittsburgh Plate Glass Co | Electrolytic production of alkali metal chlorates |
| FR2112388A2 (en) * | 1970-11-02 | 1972-06-16 | Ppg Industries Inc | |
| FR2183085A1 (en) * | 1972-04-29 | 1973-12-14 | Tdk Electronics Co Ltd | |
| US3977958A (en) * | 1973-12-17 | 1976-08-31 | The Dow Chemical Company | Insoluble electrode for electrolysis |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3711382A (en) * | 1970-06-04 | 1973-01-16 | Ppg Industries Inc | Bimetal spinel surfaced electrodes |
| JPS539273A (en) * | 1976-07-13 | 1978-01-27 | Tdk Corp | Sintered metallic oxide electrode |
| IL50217A (en) * | 1976-08-06 | 1980-01-31 | Israel State | Electrocatalytically acitve spinel type mixed oxides |
-
1978
- 1978-08-24 FR FR7824757A patent/FR2434213A1/en active Granted
-
1979
- 1979-08-13 AT AT79200445T patent/ATE3653T1/en not_active IP Right Cessation
- 1979-08-13 DE DE7979200445T patent/DE2965571D1/en not_active Expired
- 1979-08-13 FI FI792508A patent/FI65283C/en not_active IP Right Cessation
- 1979-08-13 EP EP79200445A patent/EP0008476B1/en not_active Expired
- 1979-08-14 ZA ZA00794241A patent/ZA794241B/en unknown
- 1979-08-16 AU AU50008/79A patent/AU522946B2/en not_active Ceased
- 1979-08-17 BR BR7905329A patent/BR7905329A/en not_active IP Right Cessation
- 1979-08-22 US US06/068,521 patent/US4243497A/en not_active Expired - Lifetime
- 1979-08-23 JP JP10764479A patent/JPS5531195A/en active Pending
- 1979-08-23 NO NO792732A patent/NO153110C/en unknown
- 1979-08-23 CA CA000334338A patent/CA1142129A/en not_active Expired
- 1979-08-23 ES ES483595A patent/ES483595A1/en not_active Expired
- 1979-08-23 PT PT70103A patent/PT70103A/en unknown
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3329594A (en) * | 1964-12-08 | 1967-07-04 | Pittsburgh Plate Glass Co | Electrolytic production of alkali metal chlorates |
| FR2112388A2 (en) * | 1970-11-02 | 1972-06-16 | Ppg Industries Inc | |
| FR2183085A1 (en) * | 1972-04-29 | 1973-12-14 | Tdk Electronics Co Ltd | |
| US3977958A (en) * | 1973-12-17 | 1976-08-31 | The Dow Chemical Company | Insoluble electrode for electrolysis |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2469013A1 (en) * | 1979-11-06 | 1981-05-08 | South African Inventions | ELECTROCHEMICAL ELEMENT, IN PARTICULAR A BATTERY CATHODE, AND ITS MANUFACTURING METHOD |
| EP0031948B1 (en) * | 1979-12-26 | 1986-10-15 | Asahi Kasei Kogyo Kabushiki Kaisha | A hydrogen-evolution electrode |
| US4411761A (en) * | 1980-06-28 | 1983-10-25 | Basf Aktiengesellschaft | Spinel-containing electrode and process for its production |
| FR2581082A1 (en) * | 1985-04-26 | 1986-10-31 | Int Fuel Cells Corp | METHOD OF USING ANODES CONTAINING A NICO2O4 CATALYST FOR THE ELECTROLYSIS OF POTASSIUM HYDROXIDE SOLUTIONS AND METHOD OF MANUFACTURING SUCH ANODES |
| GB2174409A (en) * | 1985-04-26 | 1986-11-05 | Int Fuel Cells Corp | Method of making an anode containing nico2o4 catalyst for the electrolysis of potassium hydroxide solutions |
| CN1323853C (en) * | 2001-12-14 | 2007-07-04 | 株式会社寿 | Double clip head mechanical propelling pencil |
Also Published As
| Publication number | Publication date |
|---|---|
| AU5000879A (en) | 1980-02-28 |
| PT70103A (en) | 1979-09-01 |
| NO153110B (en) | 1985-10-07 |
| BR7905329A (en) | 1980-05-13 |
| FR2434213A1 (en) | 1980-03-21 |
| AU522946B2 (en) | 1982-07-01 |
| ATE3653T1 (en) | 1983-06-15 |
| FI792508A (en) | 1980-02-25 |
| NO153110C (en) | 1986-01-15 |
| CA1142129A (en) | 1983-03-01 |
| NO792732L (en) | 1980-02-26 |
| FI65283B (en) | 1983-12-30 |
| ES483595A1 (en) | 1980-05-16 |
| DE2965571D1 (en) | 1983-07-07 |
| FR2434213B1 (en) | 1981-03-06 |
| ZA794241B (en) | 1980-08-27 |
| FI65283C (en) | 1984-04-10 |
| JPS5531195A (en) | 1980-03-05 |
| US4243497A (en) | 1981-01-06 |
| EP0008476B1 (en) | 1983-06-01 |
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