EP1730328A2 - Method for the production of iridium oxide coatings - Google Patents

Method for the production of iridium oxide coatings

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Publication number
EP1730328A2
EP1730328A2 EP05735009A EP05735009A EP1730328A2 EP 1730328 A2 EP1730328 A2 EP 1730328A2 EP 05735009 A EP05735009 A EP 05735009A EP 05735009 A EP05735009 A EP 05735009A EP 1730328 A2 EP1730328 A2 EP 1730328A2
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EP
European Patent Office
Prior art keywords
colloidal
ircl
iridium oxide
aqueous
salt
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.)
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Application number
EP05735009A
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German (de)
French (fr)
Inventor
Manfred Theodor Reetz
Hendrik Schulenburg
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Studiengesellschaft Kohle gGmbH
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Studiengesellschaft Kohle gGmbH
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Publication of EP1730328A2 publication Critical patent/EP1730328A2/en
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G55/00—Compounds of ruthenium, rhodium, palladium, osmium, iridium, or platinum
    • C01G55/004—Oxides; Hydroxides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
    • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
    • C23C18/1204—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material inorganic material, e.g. non-oxide and non-metallic such as sulfides, nitrides based compounds
    • C23C18/1208—Oxides, e.g. ceramics
    • C23C18/1216—Metal oxides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
    • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
    • C23C18/1225—Deposition of multilayers of inorganic material
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
    • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
    • C23C18/1229—Composition of the substrate
    • C23C18/1241—Metallic substrates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
    • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
    • C23C18/125—Process of deposition of the inorganic material
    • C23C18/1283—Control of temperature, e.g. gradual temperature increase, modulation of temperature
    • 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

Definitions

  • the present invention relates to a process for the production of coatings from iridium oxide, a colloidal iridium oxide and a process for the production of colloidal iridium oxide.
  • Metal oxide coated titanium electrodes are used in several electrochemical processes
  • Iridium oxide coatings in particular have proven their worth for the electrocatalysis of oxygen evolution. Iridium mixed oxides such as lrO x -SnO 2 , lrRuO x , lrO x -Ta 2 O 5 and lrO x -Sb 2 O 5 -SnO 2 can also be used for the coating.
  • Oxide-coated titanium electrodes are mostly produced by thermal decomposition of metal salts. Suitable metal salts are dissolved in water or alcohols and the electrodes are wetted with the solution. Then they are wetted
  • Electrodes typically heated at temperatures between 400 and 700 ° C.
  • the metal salts decompose under these conditions and form the corresponding metal oxides or mixed oxides. Electrodes manufactured in this way often have good mechanical stability, a satisfactory service life and show a low overvoltage for the development of oxygen.
  • the electrodes are expensive due to the high iridium load (at least 7.5 g iridium per square meter of titanium).
  • US Pat. No. 3,234,110 discloses that titanium sheets are coated with an ethanolic IrCl 4 solution and heated to 250-300 ° C. The process is repeated 4 times. The Ti / IrO x electrodes obtained can be used for the electrolysis of NaCl solutions become. No information is given about the life of the coating during the chlorine development.
  • U.S. Patent 3,926,751 describes a method of preparing Ti / IrTaO x electrodes. Titanium sheets are immersed in a solution of IrCI 3 and TaCI 5 12 to 15 times and each heated at 450 to 550 ° C. The electrodes show a lifespan of about 6000 h during the development of oxygen in 10% sulfuric acid.
  • U.S. Patents 5,294,317, 5,098,546, and 5,156,726 describe methods of making electrodes for oxygen evolution. Titanium electrodes, which are coated with mixed oxides, are produced by multiple, usually 10 times, immersion in butanolic solutions of H 2 lrCl 6 and tantalum ethoxide and subsequent firing at 500 ° C. A lifespan of more than 2000 hours is stated for the electrodes.
  • the electrode coatings described above due to the thermal decomposition of metal salts have the disadvantage that toxic gases are released when the electrodes are burned, in particular Cl 2 and HCl.
  • Titanium sheets are sandblasted, etched with 10% oxalic acid and immersed in an alcoholic ruthenium acetylacetonate / iridium acetylacetonate solution.
  • the wetted electrodes are then pyrolyzed at 400-600 ° C.
  • the wetting and pyrolysis process is repeated several times until a coating thickness of at least
  • the object of the invention was to develop a method which does not have the disadvantages described above and which enables coatings to be made from iridium oxides using low-chloride compounds.
  • a further object of the present invention was to coat titanium electrodes with low-chloride iridium oxides.
  • the present invention relates to a method for producing coatings of iridium oxide, which comprises the following steps: a) applying colloidal lRO x , where x is a number from 1 to 2, to a surface, b) drying the coated surface and c ) Firing the surface at a temperature of 300 to 1000 ° C, wherein steps a to c can be repeated until the desired layer thickness is obtained.
  • the method according to the invention becomes colloidal
  • the colloidal iridium oxide used according to the invention can be obtained in any manner known from the prior art.
  • a Brönsted base is added to an aqueous, alcoholic and / or aqueous-alcoholic solution of an Ir salt, optionally with stirring.
  • Particularly suitable Bronsted bases are alkali metal hydroxides, in particular NaOH or KOH.
  • a colloidal iridium oxide solution is formed.
  • the aqueous, alcoholic and / or aqueous-alcoholic solution of an Ir salt optionally with stirring.
  • Particularly suitable Bronsted bases are alkali metal hydroxides, in particular NaOH or KOH.
  • a colloidal iridium oxide solution is formed.
  • the a Brönsted base is added to an aqueous, alcoholic and / or aqueous-alcoholic solution of an Ir salt, optionally with stirring.
  • Particularly suitable Bronsted bases are alkali metal hydroxides, in particular NaOH or KOH.
  • Water-soluble Ir salts are preferably used to produce the colloidal iridium oxide.
  • the water-soluble Ir salts can be selected from the halides, nitrates, sulfates, acetates, acetylacetonates, the hydrates of the above and the
  • IrCl 3 xH 2 O, IrCl 4 xH 2 O, H 2 IrCl 6 xH 2 O, Na 2 IrCl 6 xH 2 O, K 2 IrCl 6 xH 2 O are particularly preferred.
  • the method according to the invention can be used for coating any surface that is stable at the firing temperature. It works particularly well for coating metal and metal oxide surfaces, in particular Ti, TiO 2 , ZnO, SnO 2 , and glass.
  • a particularly suitable area of application for the method according to the invention is the coating of Ti electrodes.
  • Such electrodes are used for the development of oxygen and chlorine or for the oxidation of organic residues in drinking water.
  • Colloidal iridium oxide as used in the process described above is new.
  • Another object of the present invention is accordingly a colloidal
  • Iridium oxide which has a particle size ⁇ 10 nm, in particular ⁇ 3 nm.
  • the colloidal iridium oxide can be obtained by adjusting an aqueous, alcoholic or aqueous-alcoholic solution of an Ir salt with stirring to a pH> 11, preferably> _12 and then adding the resulting mixture over a period of 3 to 72 hours a temperature of 0 to 100 ° C is stirred.
  • the iridium oxide obtained can be used for the production of coatings without further processing. If necessary, any undesirable soluble ingredients can be cleaned and removed by dialysis.
  • iridium chlorides are converted into iridium oxide colloids by basic hydrolysis.
  • the colloids could be produced as concentrated hydrosols without additional stabilizers.
  • the chloride concentration of the solution can be greatly reduced by dialysis. Titanium substrates can be wetted with the processed colloidal solution. The burning of the wetted electrodes leads to closed lrO x films. No or only minimal amounts of toxic gases are released during the firing process, since chloride may be bound in the form of the salts when the alkali metal hydroxides are used as Bronsted base as alkali metal chloride. Examples
  • Titanium sheets were sandblasted, transferred to deionized water and cleaned with ultrasound for 10 minutes. The sheets were then placed in hot (70-90 ° C.) 10% oxalic acid for 5 minutes and rinsed with deionized water before they were ultrasonically cleaned again.
  • the pretreated titanium sheets were immersed in the dialyzed colloidal lrO x solution and dried at 80 ° C for 5 minutes before being baked at 600 ° C for 5 minutes. This coating process was repeated 5 times. The burning process was carried out over 1 hour.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Ceramic Engineering (AREA)
  • Electrochemistry (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Paints Or Removers (AREA)
  • Chemically Coating (AREA)

Abstract

Disclosed is a method for producing iridium oxide coatings, comprising the following steps: a) colloidal IrOX, wherein x represents a number from 1 to 2, is applied to a surface; b) the coated surface is dried; and c) the surface is burned at a temperature ranging between 300 and 1000 °C. Steps a) to c) can be repeated until the desired layer thickness has been obtained. Using colloidal IrOX as an initial component for producing IrOX coatings prevents toxic gases from forming during the burning process.

Description

Verfahren zur Herstellung von Beschichtungen aus Iridiumoxid.-- n Process for the production of coatings from iridium oxide - n
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Beschiclntungen aus Iridiumoxid, ein kolloidales Iridiumoxid sowie ein Verfahren zur Herstellung von kolloidalem Iridiumoxid.The present invention relates to a process for the production of coatings from iridium oxide, a colloidal iridium oxide and a process for the production of colloidal iridium oxide.
Metalloxidbeschichtete Titanelektroden werden in mehreren elektrochemischen Verfahren alsMetal oxide coated titanium electrodes are used in several electrochemical processes
Anode eingesetzt. Beispiele sind die Chlor-Alkali-Elektrolyse, die Schadstoffoxidation in Wasser, die Wasserelektrolyse und die elektrolytische Metallabscheidung. In den beiden zuletzt genannten Verfahren werden metalloxidbeschichtete Anoden für die Sauerstoffentwicklung verwendet. Vor allem Iridiumoxid-Beschichtungen haben sich für die Elektrokatalyse der Sauerstoffentwicklung bewährt. Auch Iridiummischoxide wi e lrOx-SnO2, lrRuOx, lrOx-Ta2O5 und lrOx-Sb2O5-SnO2können zur Beschichtung verwendet werden.Anode inserted. Examples are chlor-alkali electrolysis, pollutant oxidation in water, water electrolysis and electrolytic metal deposition. In the latter two processes, metal oxide-coated anodes are used for the development of oxygen. Iridium oxide coatings in particular have proven their worth for the electrocatalysis of oxygen evolution. Iridium mixed oxides such as lrO x -SnO 2 , lrRuO x , lrO x -Ta 2 O 5 and lrO x -Sb 2 O 5 -SnO 2 can also be used for the coating.
Oxidbeschichtete Titanelektroden werden meist durch thermische Zersetzung von Metallsalzen hergestellt. Dabei werden geeignete Metallsalze in Wasser oder Alkoholen gelöst und die Elektroden mit der Lösung benetzt. Anschließend werden d ie benetztenOxide-coated titanium electrodes are mostly produced by thermal decomposition of metal salts. Suitable metal salts are dissolved in water or alcohols and the electrodes are wetted with the solution. Then they are wetted
Elektroden typischerweise bei Temperaturen zwischen 400 und 700°C erhitzt. Die Metallsalze zersetzen sich unter diesen Bedingungen und bilden die entsprechenden Metalloxide oder Mischoxide. Elektroden, die auf diese Weise hergestellt werden, haben oft eine gute mechanische Stabilität, eine zufriedenstellende Lebensdauer und zeigen eine geringe Überspannung für die Sauerstoffentwicklung.Electrodes typically heated at temperatures between 400 and 700 ° C. The metal salts decompose under these conditions and form the corresponding metal oxides or mixed oxides. Electrodes manufactured in this way often have good mechanical stability, a satisfactory service life and show a low overvoltage for the development of oxygen.
Im britischen Patent GB 1 399 576 werden Titanbleche in wässrige lrCI3- und TaCI5- Lösungen eingetaucht und bei Temperaturen von 450 bis 600°C pyrolysiert. Der Vorgang wird 12 bis 15mal wiederholt. Die so hergestellten Elektroden haben geringe Überspannungen für die Sauerstoffentwicklung und Lebensdauern von me hr als 2000In British Patent GB 1 399 576, titanium sheets are immersed in aqueous IrCI 3 and TaCI 5 solutions and pyrolyzed at temperatures of 450 to 600 ° C. The process is repeated 12 to 15 times. The electrodes manufactured in this way have low overvoltages for oxygen development and lifetimes of more than 2000
Stunden. Die Elektroden sind aufgrund der hohen Iridiumbeladung (mindestens 7,5 g Iridium pro Quadratmeter Titan) teuer.Hours. The electrodes are expensive due to the high iridium load (at least 7.5 g iridium per square meter of titanium).
Im US-Patent 3 234 110 wird offenbart, dass Titanbleche mit ethanolischer lrCI4-Lösung bestrichen und auf 250-300°C erhitzt werden. Der Vorgang wird 4-mal wiederholt. Die erhaltenen Ti/IrOx-Elektroden können für die Elektrolyse von NaCI-Lösungen verwendet werden. Angaben über die Lebensdauer der Beschichtung während der Chlorentwicklung werden nicht gemacht.US Pat. No. 3,234,110 discloses that titanium sheets are coated with an ethanolic IrCl 4 solution and heated to 250-300 ° C. The process is repeated 4 times. The Ti / IrO x electrodes obtained can be used for the electrolysis of NaCl solutions become. No information is given about the life of the coating during the chlorine development.
US-Patent 3 926 751 beschreibt ein Verfahren zur Präparation von Ti/lrTaOx-Elektroden. Titanbleche werden in eine Lösung aus lrCI3 und TaCI5 12 bis 15mal eingetaucht und jeweils bei 450 bis 550°C erhitzt. Die Elektroden zeigen während der Sauerstoffentwicklung in 10%iger Schwefelsäure eine Lebensdauer von etwa 6000 h.U.S. Patent 3,926,751 describes a method of preparing Ti / IrTaO x electrodes. Titanium sheets are immersed in a solution of IrCI 3 and TaCI 5 12 to 15 times and each heated at 450 to 550 ° C. The electrodes show a lifespan of about 6000 h during the development of oxygen in 10% sulfuric acid.
In den US-Patenten 5 294 317, 5 098 546 und 5 156 726 werden Verfahren zur Herstellung von Elektroden für die Sauerstoffentwicklung beschrieben. Durch mehrfaches, in der Regel 10faches, Eintauchen in butanolische Lösungen aus H2lrCI6 und Tantalethoxid und anschließendem Brennen bei 500°C werden Titanelektroden hergestellt, die mit Mischoxiden beschichtet sind. Für die Elektroden wird eine Lebensdauer von mehr als 2000 Stunden angegeben.U.S. Patents 5,294,317, 5,098,546, and 5,156,726 describe methods of making electrodes for oxygen evolution. Titanium electrodes, which are coated with mixed oxides, are produced by multiple, usually 10 times, immersion in butanolic solutions of H 2 lrCl 6 and tantalum ethoxide and subsequent firing at 500 ° C. A lifespan of more than 2000 hours is stated for the electrodes.
Die voranstehend beschriebenen Elektrodenbeschichtungen durch thermische Zersetzung von Metallsalzen haben den Nachteil, dass beim Brennen der Elektroden toxische Gase frei werden, vor allem Cl2 und HCI.The electrode coatings described above due to the thermal decomposition of metal salts have the disadvantage that toxic gases are released when the electrodes are burned, in particular Cl 2 and HCl.
F.l. Mattos-Costa, P. de Lima-Neto, S.A.S. Machado und L.A. Avaca beschreiben inF. L. Mattos-Costa, P. de Lima-Neto, S.A.S. Machado and L.A. Avaca describe in
Electrochim. Acta 1998, 44, 1515, eine weitere Möglichkeit der Herstellung von Ti/lrRuOx- Elektroden. Titanbleche werden gesandstrahlt, mit 10%iger Oxalsäure geätzt und in eine alkoholische Rutheniumacetylacetonat/Iridiumacetylacetonat-Lösung eingetaucht.Electrochim. Acta 1998, 44, 1515, another possibility for the production of Ti / lrRuO x electrodes. Titanium sheets are sandblasted, etched with 10% oxalic acid and immersed in an alcoholic ruthenium acetylacetonate / iridium acetylacetonate solution.
Anschließend werden die benetzten Elektroden bei 400-600°C pyrolysiert. Der Benetzungs- und Pyrolyseprozess wird mehrfach wiederholt, bis eine Beschichtungsdicke von mindestensThe wetted electrodes are then pyrolyzed at 400-600 ° C. The wetting and pyrolysis process is repeated several times until a coating thickness of at least
2μm erreicht ist. Bei diesem Verfahren werden zwar chlorfreie Metallsalze als Edukte verwende, der Nachteil dieses Verfahrens liegt in den deutlich höheren Kosten der verwendeten chlorfreien Metallsalze im Vergleich zu den entsprechenden Chloriden.2μm is reached. In this process, chlorine-free metal salts are used as starting materials, the disadvantage of this process is the significantly higher cost of the chlorine-free metal salts used compared to the corresponding chlorides.
Der Erfindung lag die Aufgabe zugrunde, ein Verfahren zu entwickeln, das die oben beschriebenen Nachteile nicht aufweist und es ermöglicht, Beschichtungen aus Iridiumoxiden unter Einsatz von chloridarmen Verbindungen herzustellen. Ferner lag der vorliegenden Erfindung die Aufgabe zugrunde, Titanelektroden mit chloridarmen Iridiumoxiden zu beschichten. Gegenstand der vorliegenden Erfindung ist ein Verfahren zur Herstellung von Beschichtungen aus Iridiumoxid, welches die folgenden Schritte umfasst: a) Aufbringen von kolloidalem lrOx, worin x eine Zahl von 1 bis 2 bedeutet, auf eine Oberfläche, b) Trocknen der beschichteten Oberfläche und c) Brennen der Oberfläche bei einer Temperatur von 300 bis 1000°C, wobei die Schritte a bis c wiederholt werden können, bis die gewünschte Schichtdicke erhalten ist.The object of the invention was to develop a method which does not have the disadvantages described above and which enables coatings to be made from iridium oxides using low-chloride compounds. A further object of the present invention was to coat titanium electrodes with low-chloride iridium oxides. The present invention relates to a method for producing coatings of iridium oxide, which comprises the following steps: a) applying colloidal lRO x , where x is a number from 1 to 2, to a surface, b) drying the coated surface and c ) Firing the surface at a temperature of 300 to 1000 ° C, wherein steps a to c can be repeated until the desired layer thickness is obtained.
Überraschenderweise wurde festgestellt, dass durch den Einsatz von kolloidalem lrOx alsSurprisingly, it was found that by using colloidal lrO x as
Ausgangskomponente zur Herstellung von Beschichtungen aus lrOx die Entstehung toxischer Gase während des Brennens vermieden werden kann. Als Edukte für die Herstellung der Iridiumoxidkolloide werden kostengünstige Iridiumchloride eingesetzt.Starting component for the production of coatings from lrO x the formation of toxic gases during firing can be avoided. Inexpensive iridium chlorides are used as starting materials for the production of the iridium oxide colloids.
Erfindungsgemäß wird zur Durchführung des erfindungsgemäßen Verfahrens kolloidalesAccording to the invention, the method according to the invention becomes colloidal
Iridiumoxid eingesetzt. Iridiumoxide weisen üblicherweise die Formel IrOx auf, worin x eine Zahl von 1 bis 2 bedeutet. Besonders gleichmäßige Beschichtungen können mit Teilchengrößen < 10 nm, insbesondere < 3 nm, erhalten werden.Iridium oxide used. Iridium oxides usually have the formula IrO x , where x is a number from 1 to 2. Particularly uniform coatings can be obtained with particle sizes <10 nm, in particular <3 nm.
Das erfindungsgemäß eingesetzte kolloidale Iridiumoxid kann auf beliebige aus dem Stand der Technik bekannte Weise erhalten werden. In einer bevorzugten Ausführungsform wird zu dessen Herstellung eine wässerige, alkoholische und/oder wässerig-alkoholische Lösung eines Ir-Salzes, gegebenenfalls unter Rühren, mit einer Brönsted-Base versetzt. Besonders geeignete Brönsted-Basen sind Alkalihydroxide, insbesondere NaOH oder KOH, versetzt. Es bildet sich eine kolloidale Iridiumoxid-Lösung. In einer bevorzugten Ausgestaltung wird dieThe colloidal iridium oxide used according to the invention can be obtained in any manner known from the prior art. In a preferred embodiment, a Brönsted base is added to an aqueous, alcoholic and / or aqueous-alcoholic solution of an Ir salt, optionally with stirring. Particularly suitable Bronsted bases are alkali metal hydroxides, in particular NaOH or KOH. A colloidal iridium oxide solution is formed. In a preferred embodiment, the
Lösung des Ir-Salzes auf einen pH > 1 1 , vorzugsweise > 12 eingestellt.Solution of the Ir salt adjusted to a pH> 1 1, preferably> 12.
Zur Herstellung des kolloidalen Iridium oxids werden vorzugsweise wasserlösliche Ir-Salze eingesetzt. Die wasserlöslichen Ir-Salze können ausgewählt werden aus den Halogeniden, Nitraten, Sulfaten, Acetaten, Acetylacetonaten, den Hydraten der voranstehenden sowie denWater-soluble Ir salts are preferably used to produce the colloidal iridium oxide. The water-soluble Ir salts can be selected from the halides, nitrates, sulfates, acetates, acetylacetonates, the hydrates of the above and the
Mischsalzen mit anderen Metallsalzen, insbesondere den Alkali-Iridium-Salzen. Besonders bevorzugt sind lrCI3 xH2O, lrCI4 xH2O, H2lrCI6 xH2O, Na2lrCI6 xH2O, K2lrCI6 xH2O.Mixed salts with other metal salts, especially the alkali iridium salts. IrCl 3 xH 2 O, IrCl 4 xH 2 O, H 2 IrCl 6 xH 2 O, Na 2 IrCl 6 xH 2 O, K 2 IrCl 6 xH 2 O are particularly preferred.
Das erfindungsgemäße Verfahren kann zum Beschichten von beliebigen Oberflächen angewendet werden, die bei der Brenntemperatur stabil sind. Es eignet sich besonders gut zum Beschichten von Metall- und Metalloxidoberflächen, insbesondere von Ti, TiO2, ZnO, SnO2, und Glas.The method according to the invention can be used for coating any surface that is stable at the firing temperature. It works particularly well for coating metal and metal oxide surfaces, in particular Ti, TiO 2 , ZnO, SnO 2 , and glass.
Ein besonders geeignetes Anwendungsgebiet für das erfindungsgemäße Verfahren ist das Beschichten von Ti-Elektroden. Derartige Elektroden werden für die Sauerstoffentwicklung und Chlorentwicklung oder für die Oxidation von organischen Rückständen in Trinkwasser eingesetzt.A particularly suitable area of application for the method according to the invention is the coating of Ti electrodes. Such electrodes are used for the development of oxygen and chlorine or for the oxidation of organic residues in drinking water.
Kolloidales Iridiumoxid, wie es in dem oben beschriebenen Verfahren eingesetzt wird ist neu. Ein weiterer Gegenstand der vorliegenden Erfindung ist demgemäß ein kolloidalesColloidal iridium oxide as used in the process described above is new. Another object of the present invention is accordingly a colloidal
Iridiumoxid, das eine Teilchengröße < 10 nm, insbesondere < 3 nm, aufweist.Iridium oxide, which has a particle size <10 nm, in particular <3 nm.
Das kolloidale Iridiumoxid kann erhalten werden, in dem eine wässerige, alkoholische oder wässerig-alkoholische Lösung eines Ir-Salzes unter Rühren auf eine pH-Wert > 11 , vorzugsweise >_12 eingestellt und das erhaltene Gemisch anschließend über einen Zeitraum von 3 bis 72 Stunden bei einer Temperatur von 0 bis 100°C gerührt wird.The colloidal iridium oxide can be obtained by adjusting an aqueous, alcoholic or aqueous-alcoholic solution of an Ir salt with stirring to a pH> 11, preferably> _12 and then adding the resulting mixture over a period of 3 to 72 hours a temperature of 0 to 100 ° C is stirred.
Das erhaltenen Iridiumoxid kann ohne weitere Aufbereitung zur Herstellung von Beschichtungen eingesetzt werden. Eine Reinigung und ggf. Entfernung von unerwünschten löslichen Inhaltsstoffen kann falls erforderlich durch Dialyse erfolgen.The iridium oxide obtained can be used for the production of coatings without further processing. If necessary, any undesirable soluble ingredients can be cleaned and removed by dialysis.
Mit dem erfindungsgemäßen Verfahren, wurde ein Weg gefunden bei dem Iridiumchloride durch basische Hydrolyse in Iridiumoxidkolloide überführt werden. Überraschenderweise konnten die Kolloide als konzentrierte Hydrosole ohne zusätzliche Stabilisatoren hergestellt werden. Die Chloridkonzentration der Lösung kann, falls gewünscht, durch Dialyse stark reduziert werden. Titansubstrate können mit der aufgearbeiteten kolloidalen Lösung benetzt werden. Das Brennen der benetzten Elektroden führt zu geschlossenen lrOx-Filmen. Während des Brennvorgangs werden keine oder nur minimale Mengen an toxischen Gasen frei, da eventuell Chlorid in Form der Salze gebunden ist, bei Einsatz der Alkalihydroxide als Brönsted-Base als Alkalichlorid. BeispieleWith the method according to the invention, a way has been found in which iridium chlorides are converted into iridium oxide colloids by basic hydrolysis. Surprisingly, the colloids could be produced as concentrated hydrosols without additional stabilizers. If desired, the chloride concentration of the solution can be greatly reduced by dialysis. Titanium substrates can be wetted with the processed colloidal solution. The burning of the wetted electrodes leads to closed lrO x films. No or only minimal amounts of toxic gases are released during the firing process, since chloride may be bound in the form of the salts when the alkali metal hydroxides are used as Bronsted base as alkali metal chloride. Examples
Beschichtung von Titanelektroden mit IridiumoxidCoating titanium electrodes with iridium oxide
Vorbehandlung der TitansubstratePretreatment of the titanium substrates
Titanbleche wurden gesandstrahlt, in deionisiertes Wasser überführt und mit Ultraschall 10min gereinigt. Anschließend wurden die Bleche 5min lang in heiße (70-90°C) 10%ige Oxalsäure gelegt und mit deionisiertem Wasser abgespült, bevor sie erneut 10min mit Ultraschall gereinigt wurden.Titanium sheets were sandblasted, transferred to deionized water and cleaned with ultrasound for 10 minutes. The sheets were then placed in hot (70-90 ° C.) 10% oxalic acid for 5 minutes and rinsed with deionized water before they were ultrasonically cleaned again.
Herstellung der kolloidalen Iricf/umoxidlösungPreparation of colloidal iric oxide solution
353 mg lrCI3 xH2O (54,4% Ir) wurden in 10 ml deionisiertem Wasser unter Rühren gelöst, 0,7ml gesättigte Kaliumhydroxidlösung wurde zugesetzt und 24h bei Raumtemperatur gerührt. Es entstand eine blau-violette Lösung. Die Lösung wurde 24-48h gegen deionisiertes Wasser dialysiert.353 mg lrCl 3 xH 2 O (54.4% Ir) were dissolved in 10 ml deionized water with stirring, 0.7 ml saturated potassium hydroxide solution was added and the mixture was stirred for 24 hours at room temperature. A blue-violet solution was created. The solution was dialyzed against deionized water for 24-48 hours.
Beschichtung der TitansubstrateCoating of the titanium substrates
Die vorbehandelten Titanbleche wurden in die dialysierte kolloidale lrOx-Lösung getaucht und 5 min lang bei 80°C getrocknet, bevor sie 5min bei 600°C gebrannt wurden. Dieser Beschichtungsprozess wurde 5mal wiederholt. Der Brennvorgang wurde über 1 Stunde durchgeführt. The pretreated titanium sheets were immersed in the dialyzed colloidal lrO x solution and dried at 80 ° C for 5 minutes before being baked at 600 ° C for 5 minutes. This coating process was repeated 5 times. The burning process was carried out over 1 hour.

Claims

Patentansprüche claims
1. Verfahren zur Herstellung von Beschichtungen aus Iridiumoxid, welches die folgenden Schritte umfasst: d) Aufbringen von kolloidalem lrOx, worin x eine Zahl von 1 bis 2 bedeutet, auf eine Oberfläche, e) Trocknen der beschichteten Oberfläche und f) Brennen der Oberfläche bei einer Temperatur von 300 bis 1000 °C, wobei die Schritte a bis c wiederholt werden können, bis die gewünschte Schichtdicke erhalten ist.1. A method for producing coatings of iridium oxide, which comprises the following steps: d) applying colloidal lRO x , where x is a number from 1 to 2, to a surface, e) drying the coated surface and f) burning the surface at a temperature of 300 to 1000 ° C, wherein steps a to c can be repeated until the desired layer thickness is obtained.
2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass das kolloidale lrOx, worin x eine Zahl von 1 bis 2 bedeutet, erhalten wird, indem eine wässerige, alkoholische und/oder wässerig-alkoholische Lösung eines Ir-Salzes, gegebenenfalls unter Rühren, mit einer Brönsted-Base versetzt wird.2. The method according to claim 1, characterized in that the colloidal lRO x , wherein x is a number from 1 to 2, is obtained by an aqueous, alcoholic and / or aqueous-alcoholic solution of an Ir salt, optionally with stirring, is added with a Brönsted base.
3. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass als Brönsted-Base Alkalihydroxide, insbesondere NaOH oder KOH, eingesetzt werden.3. The method according to claim 1, characterized in that alkali metal hydroxides, in particular NaOH or KOH, are used as Bronsted base.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, dass die wässerige Lösung des Ir-Salzes auf ein pH > 12, vorzugsweise > 13 eingestellt wird.4. The method according to claim 3, characterized in that the aqueous solution of the Ir salt is adjusted to a pH> 12, preferably> 13.
5. Verfahren nach einem der Ansprüche 2 bis 4, dadurch gekennzeichnet, dass das Ir-Salz ausgewählt ist aus den Halogeniden, Nitraten, Sulfaten, Acetaten, Acetylacetonaten, den Hydraten der voranstehenden sowie den Mischsalzen mit anderen Metallsalzen, insbesondere den Alkali-Iridium-Salzen, wobei lrCI3 xH2O, IrCI4xH2O, H2lrCI6 xH2O, Na2lrCI6xH2O, K2lrCI6xH2O besonders bevorzugt sind.5. The method according to any one of claims 2 to 4, characterized in that the Ir salt is selected from the halides, nitrates, sulfates, acetates, acetylacetonates, the hydrates of the foregoing and the mixed salts with other metal salts, especially the alkali iridium Salts, with IrCl 3 xH 2 O, IrCl 4 xH 2 O, H 2 IrCl 6 xH 2 O, Na 2 IrCl 6 xH 2 O, K 2 IrCl 6 xH 2 O being particularly preferred.
6. Verfahren nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass die zu beschichtenden Oberflächen ausgewählt sind aus Metall- und Metalloxidoberflächen, insbesondere aus Ti, TiO2, ZnO, SnO2, und Glas.6. The method according to any one of claims 1 to 5, characterized in that the surfaces to be coated are selected from metal and metal oxide surfaces, in particular from Ti, TiO 2 , ZnO, SnO 2 , and glass.
7. Verfahren nach Anspruch 6, dadurch gekennzeichnet, dass die zu beschichtende Oberfläche die Oberfläche einer Ti-Elektrode ist, insbesondere einer Elektrode für die Sauerstoffentwicklung und Chlorentwicklung oder einer Elektrode für die Oxidation von organischen Rückständen in Trinkwasser ist.7. The method according to claim 6, characterized in that the surface to be coated is the surface of a Ti electrode, in particular an electrode for the Oxygen evolution and chlorine evolution or an electrode for the oxidation of organic residues in drinking water is.
8. Kolloidales Iridiumoxid, das eine Teilchengröße <_10 nm, insbesondere < 3 nm, aufweist.8. Colloidal iridium oxide, which has a particle size <_10 nm, in particular <3 nm.
9. Verfahren zur Herstellung von kolloidalem Iridiumoxid, in welchem eine wässerige, alkoholische oder wässerig-alkoholische Lösung eines Ir-Salzes, gegebenenfalls unter Rühren, auf eine pH-Wert > 12, vorzugsweise > 13 eingestellt und das erhaltene Gemisch anschließend über einen Zeitraum von 3 bis 72 Stunden bei einer Temperatur von 0 bis 100 °C gerührt wird. 9. A process for the preparation of colloidal iridium oxide, in which an aqueous, alcoholic or aqueous-alcoholic solution of an Ir salt, optionally with stirring, is adjusted to a pH> 12, preferably> 13 and the mixture obtained is then used over a period of Is stirred for 3 to 72 hours at a temperature of 0 to 100 ° C.
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US8124556B2 (en) 2008-05-24 2012-02-28 Freeport-Mcmoran Corporation Electrochemically active composition, methods of making, and uses thereof
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US9790605B2 (en) 2013-06-27 2017-10-17 Yale University Iridium complexes for electrocatalysis
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KR101773564B1 (en) 2016-03-31 2017-08-31 유니테크 주식회사 A preparing method of a porous iridium electrode for electrolytic reactor
CN106854001B (en) * 2016-12-19 2018-06-19 有研亿金新材料有限公司 A kind of control reducing preparation method of iridous chloride
CN115872466B (en) * 2022-12-15 2023-09-08 苏州擎动动力科技有限公司 Iridium oxide and preparation method thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0898318A2 (en) * 1997-08-01 1999-02-24 Matsushita Electric Industrial Co., Ltd. Method for producing electrode catalyst powder

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL122179C (en) * 1959-02-06 1966-12-15
US3711385A (en) * 1970-09-25 1973-01-16 Chemnor Corp Electrode having platinum metal oxide coating thereon,and method of use thereof
IT959730B (en) * 1972-05-18 1973-11-10 Oronzio De Nura Impianti Elett ANODE FOR OXYGEN DEVELOPMENT
US3926751A (en) * 1972-05-18 1975-12-16 Electronor Corp Method of electrowinning metals
US4579942A (en) * 1984-09-26 1986-04-01 Union Carbide Corporation Polysaccharides, methods for preparing such polysaccharides and fluids utilizing such polysaccharides
JPS62254817A (en) * 1986-04-30 1987-11-06 Fuji Electric Co Ltd Anodic electrode for electroosmosis type dehydrator
US5156726A (en) * 1987-03-24 1992-10-20 Tdk Corporation Oxygen-generating electrode and method for the preparation thereof
JP2713788B2 (en) * 1989-12-22 1998-02-16 ティーディーケイ株式会社 Oxygen generating electrode and method for producing the same
KR100196094B1 (en) * 1992-03-11 1999-06-15 사토 히로시 Oxygen generating electrode
JPH0688270A (en) * 1992-09-03 1994-03-29 Permelec Electrode Ltd Electrode for electrolysis and production thereof
DE4313474C2 (en) * 1993-04-24 1997-02-13 Dornier Gmbh Double layer capacitor, which is composed of double layer capacitor units and its use as an electrochemical energy store
JPH06346267A (en) * 1993-06-14 1994-12-20 Daiso Co Ltd Electrode for generating oxygen and its production
US5851506A (en) * 1994-04-21 1998-12-22 The United States Of America As Represented By The Secretary Of The Army Electrode materials from hydrous metal and/or hydrous mixed metal oxides and method of preparing the same
FR2720542B1 (en) * 1994-05-30 1996-07-05 Alsthom Cge Alcatel Method of manufacturing a supercapacitor electrode.
FR2782280B1 (en) * 1998-08-12 2000-09-22 Inst Francais Du Petrole SUPPORTED CATALYSTS FOR USE IN ORGANIC COMPOUND TRANSACTION REACTIONS
JP2003253254A (en) * 2002-02-28 2003-09-10 Fuji Photo Film Co Ltd Luminous layer structure composed of oxide semiconductor ultrafine particles
DE10211701A1 (en) * 2002-03-16 2003-09-25 Studiengesellschaft Kohle Mbh Production of catalyst, e.g. for hydrogenation, oxidation or fuel cell electrocatalyst, involves hydrolysis and condensation of sub-group metal salt(s) in basic aqueous solution and in situ immobilization of oxide nanoparticles on support

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0898318A2 (en) * 1997-08-01 1999-02-24 Matsushita Electric Industrial Co., Ltd. Method for producing electrode catalyst powder

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