EP0867527B1 - Elektrode mit katalytischer Beschichtung für elektrochemische Prozesse und Verfahren zu deren Herstellung - Google Patents

Elektrode mit katalytischer Beschichtung für elektrochemische Prozesse und Verfahren zu deren Herstellung Download PDF

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Publication number
EP0867527B1
EP0867527B1 EP98500019A EP98500019A EP0867527B1 EP 0867527 B1 EP0867527 B1 EP 0867527B1 EP 98500019 A EP98500019 A EP 98500019A EP 98500019 A EP98500019 A EP 98500019A EP 0867527 B1 EP0867527 B1 EP 0867527B1
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Prior art keywords
electrode
metal
oxides
oxide
titanium
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EP98500019A
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English (en)
French (fr)
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EP0867527A1 (de
Inventor
Alfredo Uson Garcia
Maria Pilar Jarauta Ochoa
José Luis Hernandez Nuno
José Vicente Otal-Olivan
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Aragonesas Industrias y Energia SA
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Aragonesas Industrias y Energia SA
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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
    • C25B11/091—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

Definitions

  • the present invention relates to the manufacture of a electrocatalytic overlap electrode and establishing a process for the construction of this, so that the final product has a high resistance to passivation, without preventing good electrochemical behavior and durability satisfactory by chlorine production electrolysis and oxygen.
  • the designed electrode is formed by a substrate, electrically conductive, made with a material resistant to electrolyte and reaction products, a valve metal, on which a coating is deposited electrocatalytic consisting of a plurality of layers of a ternary mixture of valve metal oxides and platinum group metals (ruthenium dioxide and iridium dioxide).
  • the first layer being in contact with the base metal has a chemical composition enriched with valve metal oxide (titanium dioxide) against noble metal oxides (ruthenium dioxide and iridium dioxide, while in the following the valve metal oxide content, relative to that of noble metal oxides, decreases gradually in each new layer until in the most the composition is 100% metal oxides noble.
  • the molar ratio of noble metals, dioxide ruthenium to iridum dioxide remains constant in each of the layers, in the interval indicated in this memory.
  • the metal substrate consists of a metal of valve, chosen from titanium, tantalum, tungsten, zirconium, niobium, or some of their alloys.
  • the preferred metal is titanium, although other conductive metals can be used which do not are not attacked by electrolytic means.
  • the invention relates to a specific type of electrode: anodes usable in processes electrolytic, consisting of a surface layer electrocatalytic deposited on a series of layers intermediaries until reaching the internal substrate of valve metal.
  • the low concentration of noble metal in the internal layers, or close to the titanium substrate allows them to have a low catalytic activity, a property resulting advantageous for them, because they undergo minimal wear by l reactive interaction with the electrolyte which can infiltrate through the cracks or pores of the external covering.
  • Another property of the new cover is the good adhesion of the catalyst to the substrate, as well as different layers that compose it, obtained by means of the gradation of solid mixtures of oxides valve metal and noble metal, from the first layer to the last, so that the covering is enriched with noble metal and depleted in valve metal, thereby causing a better physical interconnection between a layer and the following, following the structural similarity between two adjoining layers.
  • the ultimate function of the intermediate layers is, on the one hand, to exercise as a barrier in protecting from oxidation to the metal substrate and thereby avoiding an early passivation of the electrode, and secondly, given the farm adhesion between the catalytic coating and the metallic substrate, in particular improving the properties mechanical of the electrode, without separation of material active.
  • anodes are specially indicated, although not exclusively, for any process of obtaining halogens or compounds derived therefrom by chemical dissolution in liquid absorbents, from aqueous solutions of metal halides, for example: the production of chlorine in memory cells, mercury cathode cells, diaphragm cells; the manufacture of hypoclorite by seawater electrolysis and residual water treatment. They can also be used in other electrolytic processes like making chlorate, electro-recovery of metals, protection cathodic by printed current of submerged installations in corrosive solutions, as well as buried, metal plating, organic electrosynthesis, etc.
  • This memo describes, a type of activated anode and a simple and economically viable process for the manufacture thereof, particularly indicated for its good electrochemical activity and its high resistance to passivation, for the indicated electrochemical processes previously.
  • valve metals such as titanium, tantalum, zirconium, niobium and their alloys. All these exhibit great chemical stability in various electrolytes through the passivation process undergoes by them, by means of which they are covered superficially thin and compact film of metal oxide itself, which protects the metal base underlying a subsequent chemical attack.
  • titanium is particularly commercially interesting because it presents good qualities of stability and a cost lower than rest.
  • Titanium in an oxidizing chemical means, is passivated by forming a thin surface layer of titanium dioxide (TiO 2 ) which has semiconductor properties.
  • TiO 2 titanium dioxide
  • the passivated metal then behaves as a poor conductor of electric current under normal conditions and it cannot be used directly as an anode; but it is valid when the metal / metal oxide assembly is coated with an electrocatalytic material.
  • Titanium anodes covered with materials electrochemically active also called electrocatalysts
  • electrocatalysts such as metals from the platinum or oxides of these metals
  • This type of electrode receives the name dimensionally stable anodes (DSA).
  • Valve metal anodes having this type of active covering have good electrical conductivity and low anode discharge voltages of chlorine and oxygen, it is due to the excellent electrocatalytic properties of ruthenium dioxide (RuO 2 ). Titanium dioxide (TiO 2 ) acts as a catalyst support matrix, but it also provides chemical stability against corrosion of the coating, obtaining industrially acceptable durability in the process of obtaining chlorine by electrolysis of chlorides. alkaline.
  • electrolytic operations of this type we can include: organic electrosynthesis, recovery electrolytic metals, cathodic protection, electrolysis of saline solutions diluted like water seawater, electrolytic production of chlorate, etc.
  • ruthenium oxide increases significantly by means of the addition to the active covering of iridium oxide (IrO 2 ).
  • Iridium dioxide has a slightly weaker catalytic activity than that of ruthenium for the release of oxygen; on the other hand, its chemical stability is much higher, then by mixing the two components in the same catalyst, it is possible to combine the good catalytic and stability properties of the two compounds, resulting in a catalytic coating having improved properties compared to RuO 2 ( R. Kötz, S. Stucki, J. Electrochem. Soc., 132. 103-107 (1985); R. Kötz, S. Stucki, Electrochimica Acta , 31 , 1311-1316, (1986)
  • an intermediate layer of this type consisting of a material having considerable electrocatalytic activity, has a high reactivity with the electrolyte, which can infiltrate through the layers of the coating, giving rise to reactions which wear down the barrier and this causing a reduction in physical adhesion of the catalyst to the substrate, an increase in tension, a deterioration of the coating and a passivation of the anode. Then, a barrier of these characteristics is not satisfactory for manufacturing electrodes having an acceptable duration.
  • British Patent No. 2,239,260A describes the preparation of an electrode specially suitable for its use in electrolytic processes with oxygen generation, consisting of a base metal (preferably titanium) on which apply a covering formed of two types of layers of mixture of iridium (IrO 2 ) and tantalum (Ta 2 O 5 ) oxides having a different molar ratio of iridium to tantalum in each of the layers and being these applied alternately one on the other, taking into account the fact that the deepest, in contact with the substrate, is the least enriched in noble metal.
  • the adhesion of the covering to the titanium substrate is good in this type of anodes.
  • the electrodes described are not used in processes for obtaining chlorine.
  • An electrode has also been proposed having a laminated coating, comprising an oxide layer and a layer of a platinum group metal or an oxide of said metal ( Japanese Patent No. 48072/74 ).
  • these electrodes are used by electrolysis with anodic detachment of oxygen, the passivation of these is produced in a short period of time in operation.
  • the electrode that we are describing is provided with an electrically conductive metal substrate, selected from the group of valve metals, such as titanium, tantalum, zirconium, niobium, tungsten, or some of their alloys. For his physical, chemical and economic characteristics, preferably uses titanium and its alloys.
  • the shape geometry of the substrate may be different.
  • it can be in the form of a flat plate, openwork plate, filament, expanded mesh, standard mesh "louver” etc.
  • the titanium metal substrate Before coating with the catalyst electrochemical, the titanium metal substrate is first subjected to degreasing treatments and wiping. In some occasions, the preparation of substrate requires heat treatment at temperatures high (500-700 ° C) in an inert atmosphere.
  • the surface of the substrate is developed for activation, in the subjecting to passivation using a process, among the various described for this purpose, consisting of immerse the titanium base in a solution 1M sodium hydroxide and 1M hydrogen peroxide, a temperature between 40 and 50 ° C for a duration not more than 15 hours.
  • a process among the various described for this purpose, consisting of immerse the titanium base in a solution 1M sodium hydroxide and 1M hydrogen peroxide, a temperature between 40 and 50 ° C for a duration not more than 15 hours.
  • the base metal is covered with a thin oxide film the same metal, matte gray color and very adherent.
  • the first layer is coated with a mixture of titanium oxide, ruthenium oxide and iridium oxide, a composition enriched with valve metal oxide, on the face with noble metal oxides.
  • the molar percentage of titanium oxide is 90 to 75%, while that of the noble metal oxides (RuO 2 + IrO 2 ) is 10 to 25%.
  • the content of titanium oxide decreases, while increasing that of ruthenium and iridium oxides.
  • the molar composition can vary between 87 and 70% for titanium oxide and between 13 and 30% for noble metal oxide (RuO 2 + IrO 2 ).
  • the content of noble metal oxides gradually increases with respect to the valve metal oxide, until arriving at the last layer or external coating, consisting of a solid mixture or dissolution of 70 mol% d ruthenium oxide and approximately 30 mol% of iridium oxide.
  • middle layers act in as a barrier, protecting the base metal from oxidation and thus avoid the growth of the film titanium oxide, which could lead to the interruption of passage of electric current in the interfaces of substrate / covering and then, to an early passivation of the anode.
  • All these layers constituting the covering active are formed using the technique of known mixed crystallization.
  • This technique involves co-precipitation of titanium, ruthenium and of iridium, so that the molecular network of one of them is intertwined with the molecular networks of others, thereby forming mixed crystals or solid solutions.
  • part of the solvent evaporates and the residue remaining on the substrate is subjected to a heating stage, at high temperature and in atmosphere oxidative, when the titanium, ruthenium and iridium are transformed into oxides based metallic.
  • the heat treatment is carried out in a forced air ventilation, atmospheric pressure and a temperature which can oscillate between 375 and 550 ° C.
  • the heat treatment time varies according to which layer it is.
  • the painting process can be repeated several times, in each of the stages of formation of the different layers of the covering, until finally obtaining the desired massive thickness of noble metal, which must be between 12 and 15 g / m 2 .
  • the described method for activating electrodes ensures the preparation of anodes with an overlap electrocatalytic compound for its external part of a mixture of noble metal oxides, having a concentration equal to or close to 100% and for its internal part, mixture of valve metal oxides and metal oxides platinum group, which increases its concentration of valve metal oxides as one advances towards the core titanium.
  • An electrolytic structure of this type composed of a metal substrate on which a layered overlay with noble metal ratio (ruthenium plus iridium) with valve metal (titanium), which increases as one advances from the interior towards the outside of it, has advantages to be used as anode in electrochemical processes previously indicated because by maintaining good electrochemical activity, it has a durability especially greater than that of an electrode where the overlay also consists of layers of ternary mixtures of titanium, ruthenium and of iridium, but whose molar proportion between metals is constant in all of them.
  • Valve metal may be titanium, tantalum, niobium, tungsten, or one of their alloys, but preferably it is made of titanium.
  • One of the essences of the invention is a structure as layers and the gradual variation of noble metal oxide concentrations, since the first, or most internal, supported by the metal of base, to the outermost. For reasons the number of layers is finite and oscillates between 4 and 8.
  • the proportion of 90% of TiO 2 in the first can decrease up to 80%, while increasing the RuO 2 and IrO 2 , the latter always in molar proportion 70:30.
  • the temperature and the time of the heat treatment in an oxidizing atmosphere vary from the first (or more internal) to the last (or more external).
  • the preferred temperature ranges from 375 ° to 450 ° with a duration of 15 to 20 minutes.
  • the treatment is carried out between 475 and 550 ° C. for one hour.
  • Titanium plates of dimensions 50x50x3 mm are degreased with acetone and they are subjected to chemical attack by immersing them in a solution 1 M sodium hydroxide and 1 M hydrogen peroxide for 6 hours, keeping the temperature between 40 and 50 ° C. Then we wash them with lots of water distilled to neutral reaction and dried. Of this way the substrate surface is ready for it apply the catalytic coating.
  • the molar ratio of titanium to noble metal varies from 90:10 to 0: 100.
  • Activation dissolutions are applied to the two faces of the base metal, using a brush, so that after applying each layer of painting, the solvent is evaporated in air and the sample is subjected to a heat treatment in atmosphere between 425 and 450 ° C for 15 minutes for each intermediate layer, while for the last layer heat treatment is carried out between 475 and 550 ° C and the residence time of the electrode in the oven is one hour
  • the painting, drying and thermal decomposition process of the activation dissolution is repeated the number of times necessary to obtain a thickness of the noble metal in the coating of approximately 12 g / m 2 .

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  • 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)

Claims (13)

  1. Elektrode mit katalytischer Beschichtung für elektrochemische Prozesse, wie zum Beispiel Elektrolyse von Alkalichlorid für die Herstellung von Chloralkali, Natriumchlorat und Natriumhypochlorit; Verfahren für das elektrische Niederschlagen von Metallen, das elektrische Niederschlagen von Mangandioxiden, den kathodischen Schutz durch eine ausgerichtete Strömung, organische und andere Elektrosynthese, dadurch gekennzeichnet, dass sie einen elektrisch leitenden metallischen Untergrund aufweist, der elektrolytbeständig ist und auf dem eine katalytische Beschichtung aufgebracht ist, die aus einer Reihe von übereinanderliegenden Schichten unterschiedlicher Zusammensetzung besteht, und die ein Ventilmetalloxid enthält, sowie Oxide von mindestens zwei Metalloxiden der Platingruppe, so dass das Verhältnis der Metalloxiden der Platingruppe zu dem Oxid des Ventilmetalls von der ersten Schicht ausgehend stufenweise zunimmt, wobei das Molverhältnis der Metalloxide der Platingruppe eine gemeinsame Eigenschaft ist, die immer konstant bleibt, bis auf die äussere Schicht, die ausschliesslich aus Oxiden von mindestens zwei Metallen der Platingruppe besteht und kein Ventilmetall aufweist.
  2. Elektrode nach Anspruch 1, dadurch gekennzeichnet, dass die Metallunterlage ein Ventilmetall ist, wobei es sich um Titan, Tantal, Wolfram, Zirkon, Niobium und deren Legierungen handeln kann.
  3. Elektrode nach den Ansprüchen 1 und 2, dadurch gekennzeichnet, dass die metallische Unterlage aus Titan oder dessen Legierungen besteht.
  4. Elektrode nach den Ansprüchen 1, 2 und 3, dadurch gekennzeichnet, dass die metallische Unterlage beziehungsweise der leitende metallische Träger mit einer kompakten und fest haftenden Schicht eines Oxids desselben Metalls beschichtet ist.
  5. Elektrode nach Anspruch 1, dadurch gekennzeichnet, dass es sich bei dem Ventilmetalloxid der katalytischen Beschichtung um Titanoxid handelt.
  6. Elektrode nach Anspruch 1, dadurch gekennzeichnet, dass alle Schichten der katalytischen Beschichtung aus Metallen der Platingruppe bestehen, genauer gesagt, aus Ruthenium und Iridium.
  7. Elektrode nach den Ansprüchen 1 y 6, dadurch gekennzeichnet, dass das Molverhältnis von Rutheniumoxid zu Iridiumoxid in allen Schichten gleich bleibt, wobei der Sollwert 70:30 beträgt und zwischen 72:28 und 69:31 schwanken kann.
  8. Elektrode nach den Ansprüchen 1 a 7 , dadurch gekennzeichnet, dass die Anzahl der verschiedenen die Beschichtung bildenden Schichten zwischen 4 und 8 liegt.
  9. Verfahren zur Herstellung einer Elektrode nach den Ansprüchen 1 bis 8, dadurch gekennzeichnet, dass auf die entfettete und passivierte metallische Unterlage verschiedene Schichten niedergeschlagen werden, durch das aufeinanderfolgende Aufbringen von Vorläuferlösungen von Metalloxiden, die so durch thermische Zersetzung umgesetzt werden.
  10. Verfahren zur Herstellung einer Elektrode nach den vorhergehenden Ansprüchen, dadurch gekennzeichnet, dass die Passivierung des Metalls der Unterlage mit einer wässerigen 1M-Natriumydroxid- und 1 M-Wasserstoffperoxidlösung zwischen 40-50 °C in einem Zeitraum von 6 bis 15 Stunden durchgeführt wird.
  11. Verfahren zur Herstellung einer Elektrode nach Anspruch 9, dadurch gekennzeichnet, dass das Niederschlagen jeder Schicht durch das Auftragen einer Lösung durchgeführt wird, die thermolabile Verbindungen enthält, welche durch thermische Zersetzung bei einer Temperatur von 300 °C bis 550 °C in die in jeder Schicht enthaltenen Metalloxide umgesetzt werden.
  12. Verfahren zur Herstellung einer Elektrode nach den Ansprüchen 9 und 11, dadurch gekennzeichnet, dass der Zyklus des Auftragens der Lösung und der darauffolgenden thermischen Zersetzung ein bis mehrere Male durchgeführt werden kann, um so die gewünschte Schichtdicke zu erreichen.
  13. Verfahren zur Herstellung einer Elektrode nach den Ansprüchen 9 bis 12, dadurch gekennzeichnet, dass die thermische Zersetzung der letzten Schicht oder der Zyklus des Auftragens bei einer Temperatur zwischen 475 und 550 °C über einen Zeitraum von mindestens einer Stunde stattfindet.
EP98500019A 1997-02-27 1998-01-29 Elektrode mit katalytischer Beschichtung für elektrochemische Prozesse und Verfahren zu deren Herstellung Expired - Lifetime EP0867527B1 (de)

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Cited By (1)

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US11668017B2 (en) 2018-07-30 2023-06-06 Water Star, Inc. Current reversal tolerant multilayer material, method of making the same, use as an electrode, and use in electrochemical processes

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WO2005033367A1 (en) * 2003-10-08 2005-04-14 Akzo Nobel N.V. Electrode
US7566389B2 (en) 2003-10-08 2009-07-28 Akzo Nobel N.V. Electrode
CA2492128A1 (fr) * 2005-01-05 2006-07-05 Hydro Quebec Alliages a base de ti, ru et al et usage de ceux-ci pour la synthese du chlorate de sodium
WO2011120702A1 (de) * 2010-03-31 2011-10-06 Aseca Ag Elektrolysezelle sowie anlage und verfahren zur erzeugung einer elektro-chemisch aktivierten lösung durch elektrolyse
TWI433964B (zh) 2010-10-08 2014-04-11 Water Star Inc 複數層之混合金屬氧化物電極及其製法
DE102010043085A1 (de) 2010-10-28 2012-05-03 Bayer Materialscience Aktiengesellschaft Elektrode für die elektrolytische Chlorherstellung
CN107338452A (zh) * 2017-08-16 2017-11-10 江苏唯达水处理技术股份有限公司 一种膜覆盖阴极次氯酸钠发生器
DE102017214810A1 (de) 2017-08-24 2019-02-28 Gabriele Keddo Vorrichtung und Verfahren zur Wasserdesinfektion und Herstellung eines Desinfektionsmittels
CN113816469A (zh) * 2021-10-09 2021-12-21 安徽元琛环保科技股份有限公司 一种用于电沉积梯度功能型合金涂层电极的制备方法、制得的电极
CN114875440B (zh) * 2022-04-08 2022-12-06 哈尔滨工业大学 一种钛基梯度钌涂层阳极的制备方法及应用
CN114752971B (zh) * 2022-04-11 2023-03-28 西安泰金新能科技股份有限公司 一种具有高电解耐久性的涂层钛阳极的制备方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63235493A (ja) * 1987-03-24 1988-09-30 Tdk Corp 酸素発生用電極及びその製造方法
GB9018953D0 (en) * 1990-08-31 1990-10-17 Ici Plc Electrode
DE4032417A1 (de) * 1990-10-12 1992-04-16 Univ Halle Wittenberg Dimensionsstabile anode (dsa)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11668017B2 (en) 2018-07-30 2023-06-06 Water Star, Inc. Current reversal tolerant multilayer material, method of making the same, use as an electrode, and use in electrochemical processes

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EP0867527A1 (de) 1998-09-30

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