JP5006456B2 - Electrode substrate, cathode for aqueous solution electrolysis using the same, and method for producing the same - Google Patents
Electrode substrate, cathode for aqueous solution electrolysis using the same, and method for producing the same Download PDFInfo
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Description
本発明は、水溶液の電気分解において陰極として使用する水溶液電気分解用陰極の作製に利用する電極基体に関するものであり、耐食性および電極触媒層の密着性が良好であり、前記基体上に電極触媒層を形成したアルカリ金属ハロゲン化物水溶液の電気分解用の陰極として好適な水溶液電気分解用陰極およびその製造方法に関するものである。 The present invention relates to an electrode substrate used for preparing a cathode for aqueous solution electrolysis used as a cathode in electrolysis of an aqueous solution, and has good corrosion resistance and adhesion of an electrode catalyst layer. The electrode catalyst layer is formed on the substrate. The present invention relates to an aqueous solution electrolysis cathode suitable as an electrolysis cathode for an alkali metal halide aqueous solution formed with an aqueous solution and a method for producing the same.
大量の電力を消費する電気分解工業においては、電力原単位の低下、地球温暖化対策、二酸化炭素排出量削減の観点から、製造に要するエネルギーを削減することが大きな課題とされている。そして、電気分解に要するエネルギーを削減すべく、電極、イオン交換膜、電解槽等の改良が進められている。 In the electrolysis industry that consumes a large amount of power, reducing energy required for production is a major issue from the viewpoints of reduction in power consumption, countermeasures for global warming, and reduction of carbon dioxide emissions. And in order to reduce the energy required for electrolysis, improvement of an electrode, an ion exchange membrane, an electrolytic cell, etc. is advanced.
水溶液の電気分解に使用する水溶液電気分解用陰極としては、ニッケル等の基材上に、白金族の金属あるいは金属酸化物からなる電極触媒層を形成したり、ランタン等の希土類金属あるいはその化合物等と白金族の金属等を含む電極触媒層を形成することによって、水素過電圧が低く、長寿命である水溶液電気分解用陰極が提案されている。 As cathode for aqueous electrolysis used for electrolysis of aqueous solution, an electrode catalyst layer made of platinum group metal or metal oxide is formed on a substrate such as nickel, rare earth metal such as lanthanum, or a compound thereof, etc. A cathode for an aqueous solution electrolysis that has a low hydrogen overvoltage and a long lifetime has been proposed by forming an electrode catalyst layer containing platinum metal and the like.
これらの水溶液電気分解用陰極は、水素過電圧が低く、従来の粒子状物質を表面に析出した電極触媒層表面に比べて平滑であって、イオン交換膜と密着して電気分解を行った場合にもイオン交換膜との繰り返し接触による損傷の発生は防止できるという特徴を有している。
しかしながら、水溶液電気分解用陰極の基材として用いられている金属ニッケルが、ニッケルよりも貴な電位を示す電極触媒層と接しているために、電気分解の停止期間中や大気曝露中には、ガルバニック腐食によるニッケル基材の腐食が起こりやすくなる。
These cathodes for aqueous electrolysis have a low hydrogen overvoltage, are smoother than the surface of the conventional electrode catalyst layer on which particulate matter is deposited, and are electrolyzed in close contact with the ion exchange membrane. Also, the occurrence of damage due to repeated contact with the ion exchange membrane can be prevented.
However, since the metallic nickel used as the base material for the cathode for aqueous electrolysis is in contact with the electrode catalyst layer showing a potential nobler than that of nickel, during the electrolysis stop period or during atmospheric exposure, Corrosion of the nickel base due to galvanic corrosion is likely to occur.
また、陰極、陽極、イオン交換膜を装着して電解槽を組み立てた後に、電解槽内に電解液を充填しない状態で保管していると、陰極とイオン交換膜との接触によってニッケル基材の腐食によって生成したニッケルイオン等がイオン交換膜に浸入し、イオン交換膜中にニッケル化合物として析出する等の現象が生じる結果、イオン交換膜の特性が劣化して電気分解電圧の上昇や電流効率が低下することがあった。 In addition, after assembling the electrolytic cell with the cathode, anode, and ion exchange membrane installed, if the electrolytic cell is stored without being filled with an electrolytic solution, the nickel base material can be contacted by contact between the cathode and the ion exchange membrane. As a result of nickel ions generated by corrosion entering the ion exchange membrane and precipitating as a nickel compound in the ion exchange membrane, the characteristics of the ion exchange membrane deteriorate and the electrolysis voltage increases and current efficiency increases. There was a decline.
このような問題点を解決するために、ニッケル基材表面を３５０〜５５０℃の温度で５〜６０分間加熱焼成し、該導電性基材表面にニッケル酸化物を主成分とする中間層を形成した後にランタン系金属の酸化物および水酸化物の少なくとも１種、及び白金族金属および銀から選ばれる金属単体、金属酸化物及び金属水酸化物の少なくとも１種とを含む触媒層を形成する陰極の製造方法が提案されている（例えば、特許文献１参照）。
この方法によれば、中間層と基材が本来一体である部材から構成されるため密着力が大きく、中間層の剥離や欠落は生じなくなると、記載されている。
しかしながら、電極基材からのニッケル成分の溶出の防止は図られているものとみられるが、電気分解の開始後電解槽の運転停止後には、槽電圧が上昇することが記載されている。
In order to solve such problems, the surface of the nickel substrate is heated and fired at a temperature of 350 to 550 ° C. for 5 to 60 minutes to form an intermediate layer mainly composed of nickel oxide on the surface of the conductive substrate. And forming a catalyst layer containing at least one of an oxide and a hydroxide of a lanthanum metal and at least one of a metal simple substance selected from a platinum group metal and silver, a metal oxide, and a metal hydroxide. Has been proposed (see, for example, Patent Document 1).
According to this method, it is described that since the intermediate layer and the base material are formed from a member that is originally integral, the adhesion is large, and the intermediate layer is not peeled off or missing.
However, although it seems that prevention of the elution of the nickel component from the electrode substrate is attempted, it is described that the cell voltage increases after the electrolysis cell is stopped after the start of electrolysis.
また、本出願人は、白金族金属化合物、ランタノイドを含んだ電極触媒層を有する電気分解特性に優れた水溶液電気分解用陰極を提案している（例えば、特許文献２参照）。この電極は、活性が高く水素過電圧等において優れた特性を有しているが、電解槽の運転の緊急停止時等には、より充分な逆電流への耐性を求められていた。 Further, the present applicant has proposed an aqueous electrolysis cathode having an electrolysis characteristic having an electrode catalyst layer containing a platinum group metal compound and a lanthanoid (see, for example, Patent Document 2). This electrode is highly active and has excellent characteristics such as hydrogen overvoltage. However, it has been required to have sufficient resistance to reverse current at the time of emergency stop of the operation of the electrolytic cell.
本発明は、ニッケルを基材とした水溶液電気分解用陰極として、電極基材からのニッケルの溶出を防止し、陽極、イオン交換膜、陰極の三者を一体にして組み立てた電解槽を大気中で保管した場合、あるいは電解槽の運転停止時に電極基体からのニッケルの溶出を防止し、更には電解槽の緊急停止時に生じる逆電流による影響を受けにくい陰極を提供することを課題とするものであり、また、電解槽の初期運転開始時の電解槽電圧および運転停止後に再度通電した後にも電解槽電圧が低い水溶液電気分解用陰極を提供することを課題とするものである。 The present invention is a cathode for aqueous electrolysis that uses nickel as a base material, and prevents an elution of nickel from an electrode base material. It is an object of the present invention to provide a cathode that prevents elution of nickel from the electrode substrate when stored in an electrolytic cell or when the electrolytic cell is stopped, and that is not easily affected by a reverse current generated during an emergency stop of the electrolytic cell. Also, it is an object of the present invention to provide an aqueous solution electrolysis cathode having a low electrolytic cell voltage even after the electrolytic cell voltage at the start of the initial operation of the electrolytic cell and after energizing again after the operation is stopped.
本発明は、電極触媒層を形成するための電極基体であって、ニッケル表面を有する導電性基材表面に、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層が形成されている電極基体である。
前記混在層が、ニッケル原子、炭素原子、酸素原子、水素原子からなるニッケル化合物を前記導電性基材表面に塗布して熱分解することによって形成されたものである電極基体である。
前記ニッケル化合物が、ギ酸ニッケル、酢酸ニッケルのいずれかである前記の電極基体である。
The present invention relates to an electrode substrate for forming an electrode catalyst layer , wherein a mixed layer containing metallic nickel, nickel oxide and carbon atoms is formed on the surface of a conductive substrate having a nickel surface. is there.
The mixed layer is an electrode substrate formed by applying a nickel compound comprising nickel atoms, carbon atoms, oxygen atoms, and hydrogen atoms to the surface of the conductive substrate and thermally decomposing the mixture.
In the electrode substrate, the nickel compound is either nickel formate or nickel acetate.
ニッケル表面を有する導電性基材と、前記導電性基材表面に形成され、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層と、前記混在層表面に形成され、白金族の金属または白金族の金属化合物を含有する電極触媒層とを備える水溶液電気分解用陰極である。
前記電極触媒層は、更にランタノイド化合物を有する前記の水溶液電気分解用陰極である。
前記電極触媒形成層が、硝酸ルテニウムと酢酸ランタンとを含有する電極触媒層形成液を、酸素含有雰囲気において４００℃から６００℃で熱分解することによって形成されたものである前記の水溶液電気分解用陰極である。
前記電極触媒層形成液が、更に白金化合物を含有する前記の水溶液電気分解用陰極である。
前記電極触媒層が、酸化セリウムと白金を含有する前記の水溶液電気分解用陰極である。
A conductive base material having a nickel surface, a mixed layer formed on the surface of the conductive base material, containing metallic nickel, nickel oxide and carbon atoms, and formed on the mixed layer surface, a platinum group metal or a platinum group It is a cathode for aqueous solution electrolysis provided with the electrode catalyst layer containing the metal compound of.
The electrocatalyst layer is the above-described aqueous electrolysis cathode further comprising a lanthanoid compound.
The electrode catalyst layer is an electrode catalyst layer-forming solution containing a ruthenium nitrate and lanthanum acetate, the aqueous solution electrolysis and is formed by thermally decomposing at 600 ° C. from 400 ° C. in an oxygen-containing atmosphere The cathode.
The electrode catalyst layer forming solution is the aqueous solution electrolysis cathode further containing a platinum compound.
The electrode catalyst layer is the aqueous solution electrolysis cathode containing cerium oxide and platinum.
また、本発明は、電極触媒層を形成するための電極基体の製造方法であって、ニッケル表面を有する導電性基材表面に、ニッケル原子、炭素原子、酸素原子、水素原子からなるニッケル化合物を塗布し、酸素含有雰囲気において２５０℃から６００℃で熱分解することにより、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層を形成する電極基体の製造方法である。
前記ニッケル化合物が、ギ酸ニッケル、酢酸ニッケルのいずれかである前記の電極基体の製造方法である。
The present invention also relates to a method of manufacturing an electrode substrate for forming an electrode catalyst layer , wherein a nickel compound comprising nickel atoms, carbon atoms, oxygen atoms, and hydrogen atoms is formed on the surface of a conductive substrate having a nickel surface. coated, by thermally decomposing at 600 ° C. from 250 ° C. in an oxygen-containing atmosphere, metallic nickel, a method of manufacturing an electrode substrate to form a mixed layer comprising nickel oxide and carbon atoms.
In the method for producing an electrode substrate, the nickel compound is any one of nickel formate and nickel acetate.
本発明は、ニッケル表面を有する導電性基材表面に、ニッケル原子、炭素原子、酸素原子、水素原子からなるニッケル化合物を塗布し、酸素含有雰囲気において２５０℃から６００℃で熱分解することにより、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層を形成して電極基体を作製し、前記電極基体の混在層表面に、白金族の金属化合物を含有する電極触媒形成液を塗布し、酸素含有雰囲気において熱分解することによって電極触媒層を形成する水溶液電気分解用陰極の製造方法である。
前記ニッケル化合物が、ギ酸ニッケル、酢酸ニッケルのいずれかである前記の水溶液電気分解用陰極の製造方法である。
前記電極触媒層形成液が硝酸ルテニウムと酢酸ランタンとを含有し、この電極触媒層形成液を電極基体の混在層表面に塗布した後、酸素含有雰囲気において４００℃から６００℃で熱分解することによって電極触媒層を形成する前記の水溶液電気分解用陰極の製造方法である。
前記電極触媒層形成液が、更に白金化合物を含有する前記の水溶液電気分解用陰極の製造方法である。
前記電極触媒層形成液が、更に硝酸セリウムを含有する前記の水溶液電気分解用陰極の製造方法である。
The present invention, on the conductive base material surface having a nickel surface, a nickel atom, a carbon atom, an oxygen atom, a nickel compound is applied consisting of a hydrogen atom, by thermally decomposing at 600 ° C. from 250 ° C. in an oxygen-containing atmosphere, An electrode base is prepared by forming a mixed layer containing metallic nickel, nickel oxide and carbon atoms, and an electrode catalyst-forming liquid containing a platinum group metal compound is applied to the mixed layer surface of the electrode base, and contains oxygen. It is a manufacturing method of the cathode for aqueous solution electrolysis which forms an electrode catalyst layer by thermally decomposing in an atmosphere.
In the method for manufacturing the cathode for aqueous electrolysis, the nickel compound is either nickel formate or nickel acetate.
The electrode catalyst layer forming liquid contains ruthenium nitrate and lanthanum acetate, and after this electrode catalyst layer forming liquid is applied to the mixed layer surface of the electrode substrate, it is thermally decomposed at 400 ° C. to 600 ° C. in an oxygen-containing atmosphere. It is the manufacturing method of the said cathode for aqueous solution electrolysis which forms an electrode catalyst layer.
The electrode catalyst layer forming liquid further includes the platinum compound, and the method for producing the cathode for aqueous solution electrolysis.
In the method for producing the cathode for aqueous electrolysis, the electrode catalyst layer forming liquid further contains cerium nitrate.
本発明の電極基体は、ニッケル基材上にニッケルのカルボン酸化合物のように、ニッケル原子、炭素原子、酸素原子、水素原子から構成されたニッケル化合物の低温熱分解によって、金属ニッケル、ニッケル酸化物、および炭素原子を含む混在層を形成した。前記混在層の存在によって電解槽の運転を緊急停止した場合のように逆電流が流れる場合にもニッケル基材からニッケルが溶出して、イオン交換膜へ沈着することがない。更に、電気分解を開始した初期の電位安定性が高く、電気分解の開始直後から安定した運転が可能であって水素過電圧が小さな水溶液電気分解用陰極を提供することができる。 The electrode substrate of the present invention is obtained by low-temperature pyrolysis of a nickel compound composed of nickel atoms, carbon atoms, oxygen atoms, and hydrogen atoms, such as a nickel carboxylic acid compound on a nickel substrate, thereby producing metallic nickel and nickel oxide. And a mixed layer containing carbon atoms. Even when a reverse current flows as in the case where the operation of the electrolytic cell is urgently stopped due to the presence of the mixed layer, nickel is not eluted from the nickel base material and deposited on the ion exchange membrane. Furthermore, it is possible to provide an aqueous electrolysis cathode having high potential stability at the beginning of electrolysis, stable operation immediately after the start of electrolysis and low hydrogen overvoltage.
本発明は、ニッケル表面を有する導電性基材表面に、金属ニッケル、ニッケル酸化物、および炭素原子を含む混在層を設けた電極基材、および前記基体表面に電極触媒層を設けた水溶液電気分解用陰極を提供するものである。
本発明においてニッケル表面を有する導電性基材とは、ニッケルのみではなく、ステンレス、鉄、銅等の導電性金属材料の表面にめっき、クラッド等によってニッケル層を形成したものを意味する。これらを以下の説明においてはニッケル基材とも称す。
本発明はニッケル基材からのニッケルの溶出を防止するとともに、電解槽への通電開始時の電位安定性を向上することが可能であって、電解槽の運転を緊急に停止した場合の逆電流による電極への悪影響を防止することが可能な電極を提供することができる。
また、本発明の電極は、白金族金属もしくは白金族金属化合物を含有し、更にランタノイド化合物を含む電極触媒層を形成した水溶液電気分解用陰極において、その特性をより一層発揮するものである。
The present invention, on the conductive base material surface having a nickel surface, metallic nickel, nickel oxide, and mixed layer formed electrode substrate comprising carbon atoms, and an aqueous solution electricity to the base surface provided with the electrode catalyst layer A cathode for decomposition is provided.
In the present invention, the conductive base material having a nickel surface means not only nickel but also a surface of a conductive metal material such as stainless steel, iron, copper, etc., with a nickel layer formed by plating, cladding, or the like. These are also referred to as nickel bases in the following description.
The present invention prevents the elution of nickel from the nickel base material and can improve the potential stability at the start of energization to the electrolytic cell, and the reverse current when the operation of the electrolytic cell is urgently stopped It is possible to provide an electrode capable of preventing adverse effects on the electrode due to the above.
The electrode of the present invention further exhibits the characteristics of an aqueous electrolysis cathode containing a platinum group metal or a platinum group metal compound and further having an electrode catalyst layer containing a lanthanoid compound .
本発明の電極基体は、金属ニッケル、ニッケル酸化物、および炭素原子を含む混在層を表面に有しており、電解槽の運転中に緊急に電解電流を遮断して運転を停止した場合に生じる逆電流による陽分極時にも破壊されることがなく、再度の通電後には停止前と同様に運転することができるという特徴を有している。
前記混在層は、その分析結果から金属ニッケル、ニッケル酸化物、および炭素原子が混在する層であることが明かであるが、このような混在層を設けたことによって優れた特性が得られる理由は定かではないが、導電性基材のニッケル表面との密着性が良好であると共に、前記混在層が陽分極された場合にも耐食性を有するとともに、導電性基体の表面との腐食反応を抑制しているものと推察される。
The electrode substrate of the present invention has a mixed layer containing metallic nickel, nickel oxide, and carbon atoms on the surface, and occurs when the operation is stopped by urgently interrupting the electrolytic current during operation of the electrolytic cell. It is not destroyed even during anodic polarization due to reverse current, and can be operated in the same way as before stopping after being energized again.
It is clear from the analysis results that the mixed layer is a layer in which metallic nickel, nickel oxide, and carbon atoms are mixed, but the reason why excellent characteristics can be obtained by providing such a mixed layer is as follows. Although it is not certain, it has good adhesion to the nickel surface of the conductive substrate, and has corrosion resistance even when the mixed layer is positively polarized, and suppresses the corrosion reaction with the surface of the conductive substrate. It is presumed that
また、前記混在層は、ニッケルの有機酸塩を含有する塗布液を塗布し、大気中等の酸素含有雰囲気において焼成することによって形成することができる。
また、ニッケルの有機酸塩としては、酢酸ニッケル、ギ酸ニッケルなどを用いることができる。
前記混在層を形成するための焼成温度としては２５０℃〜６００℃が好ましく、２５０℃〜５００℃とすることがより好ましい。
焼成時間は５分〜６０分が好ましく、５分〜３０分とすることがより好ましい。
The mixed layer can be formed by applying a coating solution containing an organic acid salt of nickel and baking in an oxygen-containing atmosphere such as the air.
Moreover, nickel acetate, nickel formate, etc. can be used as the organic acid salt of nickel.
The firing temperature for forming the mixed layer is preferably 250 ° C to 600 ° C, and more preferably 250 ° C to 500 ° C.
The firing time is preferably 5 minutes to 60 minutes, and more preferably 5 minutes to 30 minutes.
酢酸ニッケル、ギ酸ニッケル等のカルボン酸ニッケル化合物は、硝酸ニッケル、硫酸ニッケル等の無機塩に比べて、低温度で熱分解反応が進行すると共に、焼成時に金属の腐食を引き起こす可能性がある窒素酸化物、硫黄酸化物等の酸性気体を生成することがない。したがって、ニッケル基材に悪影響を及ぼすことがないものとみられる。また、焼成炉から排出される気体も格別の除害設備を設けることが不要であって、作業環境も良好であるという特徴を有している。
また、カルボン酸ニッケル化合物のうち、酢酸ニッケル、ギ酸ニッケルは、水に対する溶解度が大きいので水溶液として塗布することができる。
Compared with inorganic salts such as nickel nitrate and nickel sulfate, nickel carboxylate compounds such as nickel acetate and nickel formate undergo a thermal decomposition reaction at a low temperature and can cause corrosion of metals during firing. It does not produce acidic gases such as products and sulfur oxides. Therefore, it is considered that the nickel base material is not adversely affected. Further, the gas exhausted from the firing furnace does not need to be provided with a special detoxification facility, and has a feature that the working environment is also good.
Of the nickel carboxylate compounds, nickel acetate and nickel formate can be applied as an aqueous solution because of their high solubility in water.
前記の金属ニッケル、ニッケル酸化物および炭素原子を含む混在層は膜厚が厚過ぎると抵抗損失が大きくなり、膜厚が薄過ぎると効果が不十分なものとなる。したがって、混在層の厚みは０．００１μｍ〜１μｍとすることが好ましい。 When the mixed layer containing metallic nickel, nickel oxide and carbon atoms is too thick, the resistance loss becomes large, and when the thickness is too thin, the effect becomes insufficient. Therefore, the thickness of the mixed layer is preferably 0.001 μm to 1 μm.
次いで、導電性基材面に形成された金属ニッケル、ニッケル酸化物、炭素原子を含む混在層上に電極触媒層を被覆する。
電極触媒層は、白金族の金属または白金族の金属化合物を含有する層、または更にランタノイド化合物からなるランタノイド系成分を含有する層である。
ランタノイド化合物からなるランタノイド成分と、白金族金属、白金族金属化合物からなる白金族成分から構成されているものが好ましい。
電極触媒層のランタノイド系成分、白金族金属、白金族金属化合物成分は、低水素過電圧と、食塩水のイオン交換膜電解法において使用する陰極として大きな耐性を有している。
電極触媒層は、ランタノイド化合物、白金族金属、あるいは白金族金属化合物を溶解、あるいは分散した電極触媒形成液を塗布し、酸素含有雰囲気において熱分解することによって形成することができる。
Next, the electrode catalyst layer is coated on the mixed layer containing metallic nickel, nickel oxide, and carbon atoms formed on the conductive base material surface.
The electrode catalyst layer is a layer containing a platinum group metal or a platinum group metal compound, or a layer containing a lanthanoid component composed of a lanthanoid compound.
Those composed of a lanthanoid component comprising a lanthanoid compound and a platinum group component comprising a platinum group metal or a platinum group metal compound are preferred.
The lanthanoid-based component, platinum group metal, and platinum group metal compound component of the electrode catalyst layer have a high resistance as a low hydrogen overvoltage and a cathode used in an ion exchange membrane electrolysis method of a saline solution.
The electrode catalyst layer can be formed by applying an electrode catalyst forming solution in which a lanthanoid compound, a platinum group metal, or a platinum group metal compound is dissolved or dispersed, and thermally decomposing in an oxygen-containing atmosphere.
また、ランタノイド系成分としては、原子番号５７から７１のランタン、セリウム、プラセオジム、ネオジム、プロメチウム、サマリウム、ユウロピウム、ガドリウム、テルビウム、ジスプロシウム、ホルミウム、エルビウム、ツリウム、イッテルビウム及びルテチウムを挙げることができるが、なかでも、ランタン、セリウムを使用することが好ましい。また、ランタノイド系成分がランタンである場合は、酢酸ランタン等のカルボン酸塩が好ましく、セリウムの場合には硝酸セリウムが好ましい。 Examples of the lanthanoid component include lanthanum having an atomic number of 57 to 71, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Of these, lanthanum and cerium are preferably used. In addition, when the lanthanoid component is lanthanum, a carboxylic acid salt such as lanthanum acetate is preferable, and in the case of cerium, cerium nitrate is preferable.
また、白金族成分には、白金、パラジウム、ルテニウム、イリジウム等が挙げられる。白金を使用する場合には電極触媒形成液中にはジニトロジアンミン白金塩として、ルテニウムを使用する場合には硝酸ルテニウムとして電極触媒形成液に溶解させることが好ましい。このように塩素を含有しない化合物を用いることによって、電極触媒層の形成時に、混在層およびニッケル基材への悪影響を防止することが可能となる。
また、電極触媒形成液中の白金族原子とランタノイド原子の原子比は３０／７０〜９０／１０であることが好ましい。
Platinum group components include platinum, palladium, ruthenium, iridium, and the like. In the case of using platinum, it is preferable to dissolve in the electrode catalyst forming solution as dinitrodiammine platinum salt in the electrode catalyst forming solution and in the case of using ruthenium as ruthenium nitrate. By using a compound that does not contain chlorine in this way, it is possible to prevent adverse effects on the mixed layer and the nickel base material when the electrode catalyst layer is formed.
The atomic ratio of platinum group atoms to lanthanoid atoms in the electrode catalyst forming liquid is preferably 30/70 to 90/10.
電極触媒形成液を混在層が形成された電極基材に塗布して乾燥を行った後、焼成によって熱分解を行うことによって電極触媒層を形成する。塗布、乾燥、および焼成の操作は複数回行うことによって厚みを調整しても良い。
乾燥は、温度６０〜８０℃で１０〜２０分間行い、焼成は酸素含有雰囲気において４００〜６００℃の温度で１０〜２０分間行うことができる。
また、形成する電極触媒層の厚さは３ 〜６μｍとすることが好ましい。
An electrode catalyst layer is formed by applying an electrode catalyst forming liquid to an electrode substrate on which a mixed layer is formed and drying, followed by pyrolysis by firing. You may adjust thickness by performing operation of application | coating, drying, and baking in multiple times.
Drying can be performed at a temperature of 60 to 80 ° C. for 10 to 20 minutes, and baking can be performed at a temperature of 400 to 600 ° C. for 10 to 20 minutes in an oxygen-containing atmosphere.
In addition, the thickness of the electrode catalyst layer to be formed is preferably 3 to 6 μm.
このように形成された電極触媒層は、水溶液電気分解用の陰極としての水素発生反応における触媒活性に優れると共に、低い電流密度のみならず高電流密度下で電気分解を行う場合であっても長期間にわたって低水素過電圧を維持することができる。また、陰極面は電流均一性にも優れ、またイオン交換膜と陰極とを接触して電気分解を行った場合にもイオン交換膜が重金属によって汚染されることを防止できる。
また、この電極触媒層を有する水溶液電気分解用陰極では、大気暴露された場合であっても電極触媒層が酸化等によって劣化を防止することができる。
The electrode catalyst layer thus formed is excellent in catalytic activity in the hydrogen generation reaction as a cathode for aqueous solution electrolysis, and is long even when electrolysis is performed not only at a low current density but also at a high current density. A low hydrogen overvoltage can be maintained over a period of time. Further, the cathode surface is excellent in current uniformity, and the ion exchange membrane can be prevented from being contaminated by heavy metals even when the ion exchange membrane and the cathode are brought into contact with each other for electrolysis.
Further, in the aqueous solution electrolysis cathode having the electrode catalyst layer, the electrode catalyst layer can be prevented from being deteriorated by oxidation or the like even when exposed to the atmosphere.
また、導電性基材上に電極触媒形成液を塗布した後に、酸素含有雰囲気において熱分解して形成された電極触媒層は、電極触媒層形成用の金属化合物を形成する金属以外の成分として、塩素化合物を含有していないので、電極基材、混在層、及び電極触媒層に対して悪影響を及ぼさないものと考えられる。
従来、電極触媒として作用する酸素含有雰囲気において加熱することによって酸化ルテニウム等を形成する際には、一般に塩化ルテニウムを用いていたが、本発明のように塩素化合物が生成することがない硝酸ルテニウム等の塩類を用いることが好ましい。
In addition, the electrode catalyst layer formed by thermally decomposing in an oxygen-containing atmosphere after applying the electrode catalyst forming liquid on the conductive substrate is a component other than the metal that forms the metal compound for forming the electrode catalyst layer. Since no chlorine compound is contained, it is considered that the electrode base material, the mixed layer, and the electrode catalyst layer are not adversely affected.
Conventionally, when ruthenium oxide or the like is formed by heating in an oxygen-containing atmosphere that acts as an electrode catalyst, ruthenium chloride is generally used, but ruthenium nitrate that does not produce a chlorine compound as in the present invention. It is preferable to use the salts of
本発明において、ルテニウム成分とともに使用するランタノイドのカルボン酸塩を使用する場合には、例えば、酢酸ランタン、ギ酸ランタン及びシュウ酸ランタン等の群から選ばれる１種または２種以上のカルボン酸ランタンを用いるのが好ましく、溶解度が大きな酢酸ランタン等が好ましい。
特に、ランタンのカルボン酸塩からは、電極触媒層を形成する熱分解工程における４００ないし６００℃の酸素含有雰囲気においては、オキシ炭酸塩、あるいは炭酸塩が生成するものと考えられる。
オキシ炭酸塩、炭酸塩の存在は、電極触媒層中に均一に炭素原子が存在していることによっても確認することができる。このように、ランタンのカルボン酸塩の熱分解によって電極触媒層中に炭素原子を含む化合物が存在していることが水溶液電気分解用陰極の電気化学的特性にも寄与しているものと考えられる。
In the present invention, when the lanthanoid carboxylate used together with the ruthenium component is used, for example, one or more lanthanum carboxylates selected from the group of lanthanum acetate, lanthanum formate, lanthanum oxalate and the like are used. Of these, lanthanum acetate having a high solubility is preferred.
In particular, it is considered that oxycarbonate or carbonate is produced from lanthanum carboxylate in an oxygen-containing atmosphere at 400 to 600 ° C. in the thermal decomposition process for forming the electrode catalyst layer.
The presence of oxycarbonate and carbonate can also be confirmed by the presence of carbon atoms uniformly in the electrode catalyst layer. Thus, the presence of a compound containing carbon atoms in the electrode catalyst layer due to thermal decomposition of the lanthanum carboxylate is considered to contribute to the electrochemical characteristics of the cathode for aqueous electrolysis. .
また、本発明の水溶液電気分解用陰極は、電解槽の運転を停止して電解槽から取り出して大気中に放置した後に、再度、電解槽に装着して運転した場合でも、電極の特性の劣化が見られなかった。このことは、本発明の硝酸ルテニウムとランタンのカルボン酸塩から形成された電極触媒層が大気中で特性が変化しないことを示している。
また、電極基材が緻密な、金属ニッケル、ニッケル酸化物、炭素原子を含む混在層および電極触媒層で覆われているものと考えられる。
更に、電極の導電性基材が緻密な混在層および電極触媒層で覆われているために、導電性基材の金属成分の溶出等による劣化がなく、その結果、金属成分の溶出によるイオン交換膜への悪影響を防止し、長期間の安定な運転が可能であるという特徴も有している。
In addition, the cathode for aqueous electrolysis of the present invention is a deterioration of electrode characteristics even when the electrolytic cell is stopped and taken out of the electrolytic cell and left in the atmosphere, and then mounted on the electrolytic cell again and operated. Was not seen. This indicates that the characteristics of the electrode catalyst layer formed from the ruthenium nitrate and the lanthanum carboxylate of the present invention do not change in the atmosphere.
Further, it is considered that the electrode base material is covered with a dense metallic nickel, nickel oxide, mixed layer containing carbon atoms, and an electrode catalyst layer.
Furthermore, since the conductive substrate of the electrode is covered with a dense mixed layer and an electrode catalyst layer, there is no deterioration due to elution of the metal component of the conductive substrate, resulting in ion exchange due to elution of the metal component. It also has the feature of preventing adverse effects on the membrane and enabling stable operation over a long period of time.
また、本発明の電極触媒層の電極触媒形成液には、ルテニウム化合物、ランタンのカルボン酸塩に加えて、塩素原子を含まない白金化合物を配合したものを用いることによって電極触媒層中に白金を含有せしめても良い。
電極触媒層にルテニウム、ランタンに加えて白金を含有させることによって効果が得られる理由は定かではないが、通電後の電極触媒層の性能の劣化を防止し、電極触媒層の減耗を抑制する効果が得られた。
Further, in the electrode catalyst forming liquid of the electrode catalyst layer of the present invention, platinum is added to the electrode catalyst layer by using a compound containing a ruthenium compound and a lanthanum carboxylate and a platinum compound containing no chlorine atom. It may be included.
The reason why the effect can be obtained by including platinum in addition to ruthenium and lanthanum in the electrode catalyst layer is not clear, but it prevents the deterioration of the performance of the electrode catalyst layer after energization and suppresses the depletion of the electrode catalyst layer was gotten.
また、塩素原子を含まない白金化合物を配合する場合には、電極触媒層の電極触媒形成液中の、Ｐｔ／Ｌａの原子比を０．００５以上とすることが好ましく、０．００５よりも小さい場合には、充分な効果を得ることはできない。 Further, when a platinum compound containing no chlorine atom is blended, the atomic ratio of Pt / La in the electrode catalyst forming liquid of the electrode catalyst layer is preferably 0.005 or more, and is smaller than 0.005 In some cases, a sufficient effect cannot be obtained.
塩素原子を含有しない白金化合物としては、ジニトロジアンミン白金、ヘキサヒドロキソ白金酸の少なくともいずれか一種を用いるのことができる。また、白金の存在によって電極触媒層の減耗をより一層効果的に抑制することができるので、電極触媒層の厚さが５μｍ以下の厚みであっても長期間にわたって水素発生反応に対して十分な触媒活性を維持できる。 As the platinum compound not containing a chlorine atom, at least one of dinitrodiammine platinum and hexahydroxoplatinic acid can be used. In addition, since the electrode catalyst layer can be more effectively suppressed from depletion due to the presence of platinum, even if the electrode catalyst layer has a thickness of 5 μm or less, it is sufficient for a hydrogen generation reaction over a long period. The catalytic activity can be maintained.
また、本発明の水溶液電気分解用陰極の電極触媒層の形成は、酸素を含む雰囲気で４００℃から６００℃の温度において熱処理することが好ましく、４６０℃から５４０℃の温度において熱処理することがより好ましい。４００℃未満では水素発生反応に対する電極触媒活性に優れた被覆層が形成され難くなり、一方、６００℃を超えると導電性基材が酸化され易くなる。酸素を含む雰囲気としては、空気、または酸素１００体積％までの酸素富加した雰囲気が挙げられる。 In addition, the electrode catalyst layer of the aqueous electrolysis cathode of the present invention is preferably heat-treated in an oxygen-containing atmosphere at a temperature of 400 ° C. to 600 ° C., more preferably at a temperature of 460 ° C. to 540 ° C. preferable. If it is less than 400 degreeC, it will become difficult to form the coating layer excellent in the electrocatalytic activity with respect to hydrogen generating reaction, and on the other hand, if it exceeds 600 degreeC, an electroconductive base material will become easy to be oxidized. Examples of the atmosphere containing oxygen include air or an atmosphere enriched with oxygen up to 100% by volume of oxygen.
また、本発明の水溶液電気分解用陰極の電極触媒層が白金を含有する場合には、白金がより貴な酸化還元電位を有することから、ガルバニック腐食によるニッケル基材の腐食が起こりやすくなるものと考えられるが、本発明の電極基体は、表面に金属ニッケル、ニッケル酸化物、炭素原子を含む混在層を有するので、電極基材の腐食反応が抑制される結果、白金を含有する電極触媒層を有する場合にも、電極基材のニッケルの腐反応食を抑制することが可能と考えられる。 In addition, when the electrode catalyst layer of the aqueous solution electrolysis cathode of the present invention contains platinum, since platinum has a more noble redox potential, corrosion of the nickel base due to galvanic corrosion is likely to occur. Although the electrode substrate of the present invention has a mixed layer containing metallic nickel, nickel oxide, and carbon atoms on the surface, the electrode catalyst layer containing platinum is suppressed as a result of suppressing the corrosion reaction of the electrode substrate. Even if it has, it is considered possible to suppress the corrosion reaction of nickel of the electrode base material.
また、水溶液電気分解用陰極の電極触媒層に貴金属を用いた場合、通電までの保管時や通電の停止中に生じる基材のニッケルの溶出がイオン交換膜へ与える損傷が懸念される。この現象は、水溶液電気分解用陰極が電解分解において使用する前の状態よりも電気分解を行った後に、陰極を保管、あるいは電気分解電流の通電を停止した場合の方がより顕著に現れる。
これは、未電気分解状態では基材のニッケル表面が安定な酸化皮膜によって被覆されているが、電気分解後には酸化皮膜が溶出して基材のニッケル表面が腐食反応を起こし易くなっているためと考えられている。
Moreover, when a noble metal is used for the electrode catalyst layer of the aqueous solution electrolysis cathode, there is a concern about the damage to the ion exchange membrane caused by the elution of the base material nickel during storage until energization or while the energization is stopped. This phenomenon appears more prominently when the cathode is stored or the electrolysis current is turned off after the electrolysis of the aqueous solution electrolysis cathode is performed before the electrolysis.
This is because the nickel surface of the base material is coated with a stable oxide film in an unelectrolyzed state, but after the electrolysis, the nickel surface of the base material is likely to cause a corrosion reaction. It is believed that.
また、後述する実施例、比較例において、通電開始後の水溶液電気分解用陰極とイオン交換膜とを接触させた場合のイオン交換膜へのニッケル汚染を比較しているが、カルボン酸ニッケル化合物によって形成した混在層は未電気分解試料からニッケルの溶出は認められなかったが、硫酸ニッケルを混在層の形成用の塗布材料に使用した場合には、未電気分解試料にも関わらずニッケルの溶出が認められた。これは、混在層の成分分析から、硫酸ニッケルでは、熱分解されず塩の状態で残存しているものがあり、安定な混在層が形成されていないことがわかる。
また、高温での焼成の方がニッケル酸化物は形成され易いが、低温度で混在層を形成する方が電気分解の開始初期の電位安定性が向上がみられる。
Moreover, in the examples and comparative examples described later, nickel contamination on the ion exchange membrane when the cathode for aqueous electrolysis after the start of energization is brought into contact with the ion exchange membrane is compared. In the formed mixed layer, nickel elution was not observed from the non-electrolyzed sample, but when nickel sulfate was used as the coating material for forming the mixed layer, nickel was not dissolved regardless of the non-electrolyzed sample. Admitted. From the component analysis of the mixed layer, nickel sulfate remains in a salt state without being thermally decomposed, indicating that a stable mixed layer is not formed.
In addition, nickel oxide is more easily formed by firing at a high temperature, but potential stability at the beginning of electrolysis is improved by forming a mixed layer at a low temperature.
また、後述の実施例、比較例で示すように、本発明の金属ニッケル、ニッケル酸化物、および炭素原子を含む混在層は、陽分極した場合にもニッケル基材を大気中で焼成して作製したニッケル酸化物層に比べて、耐食性が大きいという特徴を有しており、陽分極時にも混在層の破壊が進行しないという特徴を有している。
したがって、電解槽の運転中に電解分解を緊急停止した場合のように、陰極が陽分極して逆電流が流れた場合にも、前記混在層の破壊が進行せず、再通電後には運転停止前と同様の性能を発揮することができる。
Further, as shown in Examples and Comparative Examples described later, the mixed layer containing metallic nickel, nickel oxide, and carbon atoms of the present invention is produced by firing a nickel base material in the atmosphere even when anodic polarization is performed. Compared to the nickel oxide layer, it has a feature of high corrosion resistance and has a feature that the destruction of the mixed layer does not proceed even during anodic polarization.
Therefore, even when the electrolytic decomposition is urgently stopped during the operation of the electrolytic cell, even when the cathode is positively polarized and a reverse current flows, the destruction of the mixed layer does not proceed and the operation is stopped after re-energization. The same performance as before can be exhibited.
これらのことから、本発明は、白金族金属あるいはその化合物を含有する電極触媒皮膜を有する水溶液電気分解用陰極において、電極基材の表面に形成する混在層としては、低温での生成が可能であるカルボン酸ニッケル化合物が好ましいことを示している。
また、電解槽への通電開始後の電位安定性を向上させるために、混在層を低温焼成条件下においても形成する場合にも、カルボン酸ニッケル化合物の熱分解によって形成した混在層であることが好ましいことを示している。
以下に、実施例、比較例を示し本発明を説明する。
Based on these facts, the present invention is an aqueous electrolysis cathode having an electrode catalyst film containing a platinum group metal or a compound thereof, and the mixed layer formed on the surface of the electrode substrate can be produced at a low temperature. Some nickel carboxylate compounds are preferred.
Also, in order to improve the potential stability after the start of energization to the electrolytic cell, even when the mixed layer is formed even under low temperature firing conditions, it may be a mixed layer formed by thermal decomposition of a nickel carboxylate compound. It is preferable.
The present invention will be described below with reference to examples and comparative examples.
実施例１
電極基体の陽分極試験
厚さ０．９ｍｍ、縦２０ｍｍ、横２０ｍｍのニッケル製エキスパンドデッドメタルを用い、その表面に粒径５０μｍアルミナ粒子でサンドブラストして表面を粗面化して試料の電極基材とした。
電極基材を温度６０℃の濃度３０質量％硫酸中に１０分間浸漬し、エッチングすることで表面酸化皮膜と残存アルミナ粒子を除去した。
Example 1
Anode Polarization Test Using a nickel expanded dead metal having a thickness of 0.9 mm, a length of 20 mm, and a width of 20 mm, and sandblasting the surface with 50 μm alumina particles to roughen the surface, did.
The electrode base material was immersed in sulfuric acid having a concentration of 30% by mass at a temperature of 60 ° C. for 10 minutes and etched to remove the surface oxide film and the remaining alumina particles.
次にギ酸ニッケル（ＩＩ）２水和物（和光純薬工業製）の濃度０．１ｍｏｌ／Ｌの水溶液を調製し、混在層塗布液とした。先に表面処理を行った電極基材に塗布し、６０℃で３分間乾燥した後、マッフル炉（デンケン製ＫＤＦ−Ｐ８０Ｇ）で３００℃において大気中で１０分間焼成した陽分極試験試料１を陰極とし、２０ｍｍ×２０ｍｍのニッケルエキスパンデットメタルを陽極として、３２質量％、９０℃の水酸化ナトリウム水溶液を電解液として電流密度１０ｋＡ／ｍ2 の条件で１時間の第１回目の電気分解を行った。
Next, an aqueous solution of nickel formate (II) dihydrate (manufactured by Wako Pure Chemical Industries, Ltd.) having a concentration of 0.1 mol / L was prepared as a mixed layer coating solution. The positive
通電停止後、直ちに、通電方向を反転させて、陽分極試験試料１に電流密度１０Ａ／ｍ2 の条件で電気分解を行い、通電電気量に対する陽分極試験試料１の水銀／酸化水銀参照電極に対する電極電位の変化を、電極電位がニッケルの酸化還元電位から急激に貴な電位へと上昇するまで測定して通電を遮断する第１回目の陽分極試験を行った。その結果を図１に試験１として示す。
Immediately after the energization is stopped, the energization direction is reversed, and the anodic
続いて、通電方向を逆転させて、第１回目の電気分解と同様に第２回目の電気分解を行った後に、第１回目の陽分極試験と同様に第２回目の陽分極試験を行った。その結果を図１に陽分極試験２として示す。
更に、同様にして第３回目の電気分解と、第３回目の陽分極試験を行った。その結果を図１に陽分極試験３として示す。
Subsequently, after the energization direction was reversed and the second electrolysis was performed in the same manner as the first electrolysis, the second anodic polarization test was performed in the same manner as the first anodic polarization test. . The result is shown as anodic polarization test 2 in FIG.
Further, the third electrolysis and the third anodic polarization test were performed in the same manner. The result is shown as anodic polarization test 3 in FIG.
比較例１
酸化物層の比較陽分極試験
実施例１の陽分極試験試料１に代えて、ニッケル基材を５００℃で大気中で１０分間焼成してを形成した比較陽分極試験試料１を作製して、実施例１と同様にして、第１回目の比較陽分極試験、第２回目の比較陽分極試験、および第３回目の比較陽分極試験をおこなった。
その結果を、比較陽分極試験１、比較陽分極試験２、および比較陽分極試験３として、図１に示す。
本発明の電極基体は、陽分極によって電極基体を酸化する電流に対する耐性が、大気中でのニッケル基材の酸化によって形成した酸化皮膜に比べて大きいことを示している。
Comparative Example 1
Comparative anodic polarization test of oxide layer In place of the anodic
The results are shown in FIG. 1 as a comparative
The electrode substrate of the present invention shows that the resistance against current that oxidizes the electrode substrate by anodic polarization is higher than that of an oxide film formed by oxidation of a nickel substrate in the atmosphere.
実施例２
ギ酸ニッケルの熱分解生成物の確認
ニッケル板上に実施例１で調製したギ酸ニッケル水溶液を塗布し、大気中で３００℃で焼成する操作を１０回繰り返して、熱分解生成物確認試料１を作製した。
熱分解生成物確認試料１をエネルギー分散型Ｘ線分析装置（EDAX社製 Genesis-XM２型）を用いて、ギ酸ニッケルを塗布した面の１０カ所について測定した。１０カ所の平均値のニッケル、酸素、炭素の存在比は、原子比で４５．５：３９．８：１４．７であった。
次いで、焼成温度を５００℃に変えて同様にして熱分解生成物確認試料２を作製して上記と同様に測定した。１０カ所の平均値のニッケル、酸素、炭素の存在比は、原子比で５１．４：３６．７：１１．９であった。
いずれの試料からも炭素原子の存在を確認することができた。
Example 2
Confirmation of thermal decomposition product of nickel formate Applying the nickel formate aqueous solution prepared in Example 1 on a nickel plate and baking it at 300 ° C. in the atmosphere 10 times to produce thermal decomposition
The thermal decomposition
Subsequently, the pyrolysis product confirmation sample 2 was produced in the same manner while changing the firing temperature to 500 ° C. and measured in the same manner as described above. The abundance ratio of nickel, oxygen, and carbon with an average value at 10 locations was 51.4: 36.7: 11.9 in terms of atomic ratio.
The presence of carbon atoms could be confirmed from any sample.
比較例２
ニッケル基板にギ酸ニッケル水溶液を塗布しない点を除き実施例２と同様に大気中で３００℃で焼成する操作を１０回繰り返して、熱分解生成物確認比較試料１を作製して、実施例２と同様にして表面の生成物を測定した。ニッケル、酸素、炭素の存在比は、原子比で９１．１：８．９：０であった。
次いで、焼成温度を５００℃に変えて同様にして熱分解生成物確認比較試料２を作製して上記と同様に測定した。１０カ所の平均値のニッケル、酸素、炭素の存在比は、原子比で８０．９．１：１９．１：０であった。
いずれの試料からも炭素原子は存在しないことが確認できた。
Comparative Example 2
Except that the nickel formate aqueous solution was not applied to the nickel substrate, the operation of baking in the atmosphere at 300 ° C. was repeated 10 times in the same manner as in Example 2 to produce a thermal decomposition product confirmation
Next, the pyrolysis product confirmation comparative sample 2 was produced in the same manner while changing the firing temperature to 500 ° C. and measured in the same manner as described above. The abundance ratio of nickel, oxygen, and carbon with an average value at 10 locations was 80.9.1: 19.1: 0 in atomic ratio.
It was confirmed that no carbon atom was present from any sample.
実施例３、４および比較例３
酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）、ギ酸ニッケル（ＩＩ）２水和物（和光純薬工業製）、および硝酸ニッケル（ＩＩ）６水和物（和光純薬工業製）を、それぞれ３００℃、および５００℃の大気中において１０分間熱した試料を、Ｘ線回折装置（パナリティカル製 Ｘ’Ｐｅｒｔ ＰＲＯ ＭＰＤ、ターゲット：銅、加速電圧：４５ｋＶ）によって測定して、測定結果をニッケル酸化物（ＮｉＯ））とニッケル金属（Ｎｉ）の原子比で表１に示す。
Examples 3 and 4 and Comparative Example 3
Nickel acetate (II) tetrahydrate (manufactured by Wako Pure Chemical Industries), nickel formate (II) dihydrate (manufactured by Wako Pure Chemical Industries), and nickel (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries) ) Was measured with an X-ray diffractometer (X'Pert PRO MPD, manufactured by Panalytical, target: copper, acceleration voltage: 45 kV) measured for 10 minutes in the atmosphere of 300 ° C. and 500 ° C., respectively. The results are shown in Table 1 as atomic ratios of nickel oxide (NiO) and nickel metal (Ni).
実施例５
実施例１で用いたギ酸ニッケル粉末を３００℃、および５００℃の大気中において加熱して熱分解した試料を、高エネルギー加速器研究機構 放射光科学研究施設（Ｐｈｏｔｏｎ Ｆａｃｔｏｒｙ）において、ビームラインＢＬ−１２ＣでＸ線吸収微細構造（ＸＡＦＳ）を測定した。
測定は、分光器：Ｓｉ（１１１）２結晶分光器、ミラー：集光ミラー、吸収端：透過法、使用検出器：Ｉｏｎｉｚａｔｉｏｎ ｃｈａｍｂｅｒの条件で行いＸＡＮＥＳスペクトルによって存在量比を求めた。
Example 5
A sample obtained by heating and pyrolyzing the nickel formate powder used in Example 1 in an atmosphere of 300 ° C. and 500 ° C. was subjected to a beamline BL-12C at the High Energy Accelerator Research Organization Synchrotron Radiation Research Facility (Photon Factory). X-ray absorption fine structure (XAFS) was measured.
The measurement was performed under the conditions of spectrometer: Si (111) 2 crystal spectrometer, mirror: condenser mirror, absorption edge: transmission method, detector used: ionization chamber, and the abundance ratio was determined by XANES spectrum.
測定結果は、測定スペクトルに対して、成分と考えられる金属ニッケル、酸化ニッケル標準ピークから合成した合成ピークと、測定ピークの差が最小二乗法で最小になるように計算処理するＸＡＮＥＳスペクトルの一般的な解析方法によって求めてその割合を存在比とした。
３００℃で熱分解したギ酸ニッケルの生成物は、金属ニッケル３１．６％、酸化ニッケル（ＮｉＯ）６８．４％であった。
また、５００℃で熱分解したギ酸ニッケルの生成物は、金属ニッケル１８．６％、酸化ニッケル（ＮｉＯ）８１．４％であった。
The measurement result is a general XANES spectrum that is calculated and processed so that the difference between the measured peak and the synthetic peak synthesized from the metallic nickel and nickel oxide standard peaks, which are considered as components, and the measured peak is minimized by the method of least squares. The ratio was determined by a simple analysis method and was defined as the abundance ratio.
The products of nickel formate thermally decomposed at 300 ° C. were metal nickel 31.6% and nickel oxide (NiO) 68.4%.
The products of nickel formate thermally decomposed at 500 ° C. were 18.6% nickel metal and 81.4% nickel oxide (NiO).
実施例６
厚さ０．９ｍｍ、縦２０ｍｍ、横２０ｍｍのニッケル製エキスパンドデッドメタルを用い、その表面に粒径５０μｍアルミナ粒子でサンドブラストして表面を粗面化して試料の電極基材とした。
電極基材を温度６０℃の濃度３０質量％硫酸中に１０分間浸漬し、エッチングすることで表面酸化皮膜と残存アルミナ粒子を除去した。
Example 6
A nickel expanded dead metal having a thickness of 0.9 mm, a length of 20 mm, and a width of 20 mm was used, and the surface thereof was sandblasted with alumina particles having a particle size of 50 μm to roughen the surface to obtain a sample electrode substrate.
The electrode base material was immersed in sulfuric acid having a concentration of 30% by mass at a temperature of 60 ° C. for 10 minutes and etched to remove the surface oxide film and the remaining alumina particles.
次に酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）の濃度０．１ｍｏｌ／Ｌの水溶液を調製し、混在層形成液とした。表面処理を行ったニッケル製エキスパンデッドメタルに塗布し、６０℃で３分間乾燥した後、マッフル炉（デンケン製ＫＤＦ−Ｐ８０Ｇ）で大気中で３００℃において１０分間焼成した混在層形成試料１−１と、５００℃で１０分間焼成した混在層形成試料１−２を作製した。
Next, an aqueous solution of nickel acetate (II) tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) having a concentration of 0.1 mol / L was prepared as a mixed layer forming solution.
次いで、硝酸ルテニウム硝酸溶液（田中貴金属工業製）及び酢酸ランタンｎ水和物（和光純薬工業製）及びジニトロジアンミン白金硝酸溶液（田中貴金属工業製）を用いて、硝酸ルテニウム−酢酸ランタン−ジニトロジアンミン白金硝酸溶液を、原子比でＲｕ：Ｌａ：Ｐｔ＝１：１：０．０５になる電極触媒形成液１を調製した。
Next, using a ruthenium nitrate solution (manufactured by Tanaka Kikinzoku Kogyo), lanthanum acetate n hydrate (manufactured by Wako Pure Chemical Industries) and dinitrodiammine platinum nitrate solution (manufactured by Tanaka Kikinzoku Kogyo), ruthenium nitrate-lanthanum acetate-dinitrodiammine An electrocatalyst forming
先に作製した混在層形成試料１−１および１−２に電極触媒形成液１を塗布、乾燥して５００℃で１０分間焼成する操作を５回繰り返し、試験陰極１−１および１−２を作製した。 The operation for applying the electrode catalyst forming liquid 1 to the mixed layer forming samples 1-1 and 1-2 prepared above, drying and baking at 500 ° C. for 10 minutes was repeated five times, and test cathodes 1-1 and 1-2 were formed. Produced.
作製した試験陰極１−１および１−２を、試験陰極１−１の基材に用いたものと同じニッケル製エキスパンドデッドメタルを陽極とし、温度９０℃、３０質量％の水酸化ナトリウム水溶液中で、１０ｋＡ／ｍ2 の電流密度で１時間の電気分解を行った後、更に２０ｋＡ／ｍ2 の電流密度で１時間の電気分解を行った。
電気分解後の試験陰極１−１および１−２の表面を走査型電子顕微鏡（日本電子製ＪＳＭ−６４９０）によって皮膜の剥離等を観察してその結果を表２に示す。
In the produced test cathodes 1-1 and 1-2, the same nickel expanded dead metal as that used for the base material of the test cathode 1-1 was used as an anode, in a sodium hydroxide aqueous solution at a temperature of 90 ° C. and 30% by mass. After electrolysis at a current density of 10 kA / m 2 for 1 hour, electrolysis was further carried out at a current density of 20 kA / m 2 for 1 hour.
The surface of the test cathodes 1-1 and 1-2 after the electrolysis was observed with a scanning electron microscope (JSM-6490, manufactured by JEOL), and the results are shown in Table 2.
電気分解後のニッケル溶出試験
電気分解後の試験陰極１−１および１−２を、ｐＨ１１の水酸化ナトリウム水溶液に浸漬処理した陽イオン交換膜（デュポン社製Ｎ−２０３０）と密着させた状態で、９８１Ｐａの圧力を印加した状態でポリエチレン製の袋に密封して２４時間放置した。
次いで、取り出した陽イオン交換膜中のニッケルをＩＣＰ発光分光分析装置（島津製ＩＣＰＳ−８１００）にて検出してその結果を、４ｃｍ2 の面積当たりのニッケル沈着量として表２示す。
Nickel elution test after electrolysis In a state where test cathodes 1-1 and 1-2 after electrolysis are in close contact with a cation exchange membrane (N-2030 manufactured by DuPont) immersed in a sodium hydroxide aqueous solution at pH 11. , Sealed in a polyethylene bag with a pressure of 981 Pa applied and left for 24 hours.
Next, nickel in the extracted cation exchange membrane was detected with an ICP emission spectroscopic analyzer (ICPS-8100, manufactured by Shimadzu Corp.), and the results are shown in Table 2 as the amount of nickel deposited per 4 cm 2 area.
実施例７
混在層形成用材料を酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）に代えて、ギ酸ニッケル（ＩＩ）２水和物（和光純薬工業製）を用いた点を除き実施例６と同様にして、３００℃で混在層を形成した試験陰極２−１と、５００℃で混在層を形成した試験陰極２−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Example 7
Example except that nickel formate (II) dihydrate (manufactured by Wako Pure Chemical Industries) was used in place of the nickel (II) acetate tetrahydrate (manufactured by Wako Pure Chemical Industries) as the mixed layer forming material In the same manner as in Example 6, a test cathode 2-1 having a mixed layer formed at 300 ° C. and a test cathode 2-2 having a mixed layer formed at 500 ° C. were prepared, and an evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
実施例８
実施例６と同様にして、３００℃で混在層を形成した混在層形成試料３−１、および５００℃で混在層を形成した混在層形成試料３−２を作製した。
次いで、硝酸セリウムとジニトロジアンミン白金塩を原子比が Ｐｔ：Ｃｅ＝１：１になるように、濃度８質量％の硝酸に溶解し、セリウムと白金の合計濃度が５質量％である電極触媒形成液２を調製した。
電極触媒形成液２を塗布、乾燥して５００℃で１０分間焼成する操作を５回繰り返し、試験陰極３−１および３−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Example 8
In the same manner as in Example 6, a mixed layer forming sample 3-1 having a mixed layer formed at 300 ° C. and a mixed layer forming sample 3-2 having a mixed layer formed at 500 ° C. were produced.
Next, cerium nitrate and dinitrodiammine platinum salt are dissolved in nitric acid having a concentration of 8% by mass so that the atomic ratio is Pt: Ce = 1: 1, and an electrode catalyst is formed in which the total concentration of cerium and platinum is 5% by mass. Liquid 2 was prepared.
The operation of applying, drying and baking the electrode catalyst forming liquid 2 at 500 ° C. for 10 minutes was repeated 5 times to produce test cathodes 3-1 and 3-2, and an evaluation test was conducted in the same manner as in Example 6. The results are shown in Table 2.
実施例９
実施例７と同様に作製した、３００℃で混在層を形成した混在層形成試料４−１および５００℃で混在層を形成した混在層形成試料４−２を作製した。
次いで、実施例８と同様に電極触媒形成液２を塗布、乾燥して５００℃で１０分間焼成する操作を５回繰り返し、試験陰極４−１および４−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Example 9
A mixed layer forming sample 4-1 in which a mixed layer was formed at 300 ° C. and a mixed layer forming sample 4-2 in which a mixed layer was formed at 500 ° C. were prepared in the same manner as in Example 7.
Subsequently, the operation of applying the electrode catalyst forming liquid 2 in the same manner as in Example 8, drying and baking at 500 ° C. for 10 minutes was repeated 5 times to produce test cathodes 4-1 and 4-2. An evaluation test was conducted. The results are shown in Table 2.
比較例４
混在層として酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）に代えて、硫酸ニッケル（ＩＩ）６水和物（和光純薬工業製）を用いた点を除き実施例６と同様にして、混在層を３００℃で形成した比較陰極２−１と、混在層を５００℃で形成した比較陰極２−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 4
As in Example 6, except that nickel (II) sulfate hexahydrate (Wako Pure Chemical Industries) was used instead of nickel acetate (II) tetrahydrate (Wako Pure Chemical Industries) as the mixed layer. Then, comparative cathode 2-1 in which the mixed layer was formed at 300 ° C. and comparative cathode 2-2 in which the mixed layer was formed at 500 ° C. were prepared, and an evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例５
混在層として酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）に代えて、硝酸ニッケル（ＩＩ）６水和物（和光純薬工業製）を用いた点を除き実施例６と同様にして、混在層を３００℃で形成した比較陰極２−１と，混在層を５００℃で形成した比較陰極２−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 5
As in Example 6, except that nickel (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries) was used instead of nickel acetate (II) tetrahydrate (manufactured by Wako Pure Chemical Industries) as the mixed layer. Thus, a comparative cathode 2-1 in which the mixed layer was formed at 300 ° C. and a comparative cathode 2-2 in which the mixed layer was formed at 500 ° C. were prepared, and an evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例６
混在層を形成しなかった点を除き実施例６と同様にして、比較陰極３を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 6
A comparative cathode 3 was produced in the same manner as in Example 6 except that the mixed layer was not formed, and an evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例７
酢酸ニッケル等のニッケル塩を塗布せずに、ニッケル基材を大気中で５００℃で焼成して酸化皮膜を形成した点を除き実施例６と同様にして、比較陰極４を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 7
A comparative cathode 4 was prepared in the same manner as in Example 6 except that an oxide film was formed by baking a nickel base material at 500 ° C. in the air without applying a nickel salt such as nickel acetate. An evaluation test was conducted in the same manner as in FIG. The results are shown in Table 2.
比較例８
混在層として酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）に代えて、硫酸ニッケル（ＩＩ）６水和物（和光純薬工業製）を用いた以外は実施例８と同様にして、混在層を３００℃で形成した比較陰極５−１と、混在層を５００℃で形成した比較陰極５−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 8
Example 8 was used except that nickel (II) sulfate hexahydrate (Wako Pure Chemical Industries) was used instead of nickel acetate (II) tetrahydrate (Wako Pure Chemical Industries) as the mixed layer. The comparative cathode 5-1 in which the mixed layer was formed at 300 ° C. and the comparative cathode 5-2 in which the mixed layer was formed at 500 ° C. were prepared, and the evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例９
混在層として酢酸ニッケル（ＩＩ）４水和物（和光純薬工業製）に代えて、硝酸ニッケル（ＩＩ）６水和物（和光純薬工業製）を用いた以外は実施例８と同様にして、混在層を３００℃で形成した比較陰極６−１と、混在層を５００℃で形成した比較陰極６−２を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 9
Example 8 was used except that nickel nitrate (II) hexahydrate (Wako Pure Chemical Industries) was used instead of nickel acetate (II) tetrahydrate (Wako Pure Chemical Industries) as the mixed layer. The comparative cathode 6-1 in which the mixed layer was formed at 300 ° C. and the comparative cathode 6-2 in which the mixed layer was formed at 500 ° C. were prepared, and the evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例１０
混在層を形成しなかった点を除き実施例８と同様にして、比較陰極７を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 10
A comparative cathode 7 was prepared in the same manner as in Example 8 except that the mixed layer was not formed, and an evaluation test was performed in the same manner as in Example 6. The results are shown in Table 2.
比較例１１
酢酸ニッケル等のニッケル塩を塗布せずに、ニッケル基材を大気中で５００℃で焼成して酸化皮膜を形成した点を除き実施例８と同様にして、比較陰極８を作製し、実施例６と同様に評価試験を行った。その結果を表２に示す。
Comparative Example 11
A comparative cathode 8 was produced in the same manner as in Example 8, except that a nickel base such as nickel acetate was not applied and the nickel base was baked at 500 ° C. in the atmosphere to form an oxide film. An evaluation test was conducted in the same manner as in FIG. The results are shown in Table 2.
実施例１０
厚さ０．１５ｍｍのニッケル製エキスパンドデッドメタルを基材に用いた点を除き、実施例１と同様の方法で、３００℃で混在層を形成して、実施例６と同じ電極触媒形成液１を塗布して、実施例６と同様に試験陰極５を作製した。
Example 10
The same electrocatalyst forming liquid 1 as in Example 6 was formed by forming a mixed layer at 300 ° C. in the same manner as in Example 1 except that nickel expanded dead metal having a thickness of 0.15 mm was used as the base material. The test cathode 5 was produced in the same manner as in Example 6.
電極性能評価
試験電解槽に、陰極として作製した試験陰極５を装着し、陽極としてチタン製エキスパンデッドメタルを基材とした塩素発生用電極（ペルメレック電極株式会社製 ＤＳＥ ＪＰ−２０２）を装着し、２質量％の水酸化ナトリウム水溶液に浸漬処理した陽イオン交換膜（デュポン社製Ｎ−２０３０）で、陰極室と陽極室を区画すると共に、陰極、イオン交換膜、陽極を一体に接触したゼロギャップ式のイオン交換膜を組み立てた。組み立て後１５ 時間は電解液を充填せずに、電解槽を保管した。
Electrode performance evaluation A test cathode 5 prepared as a cathode is mounted in a test electrolytic cell, and a chlorine generating electrode (DSE JP-202 manufactured by Permerek Electrode Co., Ltd.) based on a titanium expanded metal is mounted as an anode. A cation exchange membrane (N-2030 manufactured by DuPont) immersed in a 2% by mass aqueous sodium hydroxide solution partitioned the cathode chamber and the anode chamber, and the cathode, the ion exchange membrane and the anode were in contact with each other. A gap-type ion exchange membrane was assembled. For 15 hours after the assembly, the electrolytic cell was stored without filling the electrolytic solution.
次に、陽極液として濃度が２００ｇ／Ｌの食塩水と、陰極液として濃度が３２質量％水酸化ナトリウム水溶液を循環して、運転温度９０℃、電流密度６ｋＡ／ｍ2 の条件で電気分解を行った。
１００日間の電気分解期間の内、５１日目と５２日目の２日間、電気分解を停止して、電解槽を解体して大気曝露下での保管を行ったが、その後の電気分解において電解槽電圧の上昇がみられず、電流効率は９７％を保持した。
１００日間の電気分解の後に電解槽を解体してイオン交換膜を観察したが、ニッケル沈着はなかった。
Next, a saline solution having a concentration of 200 g / L as an anolyte and a sodium hydroxide aqueous solution having a concentration of 32% by mass as a catholyte are circulated and electrolyzed under conditions of an operating temperature of 90 ° C. and a current density of 6 kA / m 2. went.
During the electrolysis period of 100 days, the electrolysis was stopped for 2 days on the 51st and 52nd days, and the electrolytic cell was disassembled and stored under atmospheric exposure. The cell voltage did not increase and the current efficiency was maintained at 97%.
After 100 days of electrolysis, the electrolytic cell was disassembled and the ion exchange membrane was observed, but there was no nickel deposition.
短絡性能評価
電極性能評価を行って解体した試験電解槽のイオン交換膜のみを交換して再び電気分解を行った。通電電流が電流密度６ｋＡ／ｍ2 で安定したことを確認した後、電気分解電流を遮断して、陽極と陰極を短絡させた状態で、陽極液、陰極液の供給、排出を停止して電解槽を７０℃で２時間保持した。
その後、６ｋＡ／ｍ2 電流密度で電気分解の運転を再開して１０日後の性能劣化を確認する試験を２回繰り返した。
第１回目の短絡試験後に、電解槽電圧は０．００４Ｖ上昇し、水素過電圧は０．７ｍＶ上昇した。
また、第２回目の短絡試験後に、電解槽電圧は０．００４Ｖ上昇し、水素過電圧は２．４ｍＶ上昇した。すなわち、第２回目の短絡試験後には、第１回目の短絡試験前に比べて、電解槽電圧は０．００８Ｖ、水素過電圧は３．１ｍＶ上昇したのみであった。
Short-circuit performance evaluation Only the ion exchange membrane of the test electrolytic cell disassembled by performing electrode performance evaluation was replaced, and electrolysis was performed again. After confirming that the energization current was stable at a current density of 6 kA / m 2 , the electrolysis current was cut off, and the supply and discharge of the anolyte and catholyte were stopped while the anode and cathode were short-circuited. The vessel was held at 70 ° C. for 2 hours.
Thereafter, the electrolysis operation was resumed at a current density of 6 kA / m 2 and a test for confirming performance deterioration after 10 days was repeated twice.
After the first short-circuit test, the electrolytic cell voltage increased by 0.004 V, and the hydrogen overvoltage increased by 0.7 mV.
Further, after the second short-circuit test, the electrolytic cell voltage increased by 0.004 V, and the hydrogen overvoltage increased by 2.4 mV. That is, after the second short-circuit test, the electrolytic cell voltage was only increased by 0.008 V and the hydrogen overvoltage was increased by 3.1 mV compared to before the first short-circuit test.
比較例１２
ニッケル基材を大気中で５００℃において１０分間焼成することで表面にニッケル酸化物層を形成した試料を用いた点を除き実施例１０と同様にして比較試験陰極９を作製し、実施例１０と同様にして電解したところ、実施例１０と比較すると、初期０．０１０Ｖ高い電圧となった。また、１００日間の電気分解期間の内、５１日目と５２日目の２日間、電気分解を停止して、電解槽を解体して大気曝露下での保管を行ったが、その後の電気分解において電解槽電圧の上昇がみられず、電流効率は９７％を保持した。しかし、電解槽電圧は０．０１０Ｖ上昇した。また、電解槽を解体後のイオン交換膜へのニッケル沈着は確認されなかった。
Comparative Example 12
A comparative test cathode 9 was prepared in the same manner as in Example 10 except that a sample in which a nickel oxide layer was formed on the surface by firing a nickel base material at 500 ° C. for 10 minutes in the atmosphere was used. When electrolysis was performed in the same manner as in Example 10, the initial voltage was 0.010 V higher than that in Example 10. In addition, during the electrolysis period of 100 days, the electrolysis was stopped for 2 days on the 51st and 52nd days, the electrolytic cell was disassembled and stored under atmospheric exposure. No increase in electrolytic cell voltage was observed, and the current efficiency was maintained at 97%. However, the electrolytic cell voltage increased by 0.010V. Moreover, nickel deposition on the ion exchange membrane after disassembling the electrolytic cell was not confirmed.
また、実施例１０と同様に短絡試験を２回行った。
第１回目の短絡試験後に、電解槽電圧は０．００７Ｖ上昇し、水素過電圧は７．０ｍＶ上昇した。
また、第２回目の短絡試験後に、電解槽電圧は０．０１８Ｖ上昇し、水素過電圧は６．２ｍＶ上昇した。すなわち、第２回目の短絡試験後には、第１回目の短絡試験前に比べて、電解槽電圧は０．０２５Ｖ、水素過電圧は１３．２ｍＶ上昇した。
Further, the short-circuit test was performed twice in the same manner as in Example 10.
After the first short-circuit test, the electrolytic cell voltage increased by 0.007 V, and the hydrogen overvoltage increased by 7.0 mV.
In addition, after the second short-circuit test, the electrolytic cell voltage increased by 0.018 V, and the hydrogen overvoltage increased by 6.2 mV. That is, after the second short-circuit test, the electrolytic cell voltage increased by 0.025 V and the hydrogen overvoltage increased by 13.2 mV compared to before the first short-circuit test.
本発明の電極基体は、ニッケル表面に形成した層の耐食性が大きく、電気分解中に生じた逆電流によっても破壊されることはない。また、前記電極基体上に電極触媒層を形成した水溶液電気分解用陰極は、水素過電圧が低く、通電停止時においてもニッケル基材表面のニッケルが溶出することがなく、イオン交換膜電解槽の陰極として使用した場合にも、イオン交換膜中へのニッケルの沈着量が少なく、長期間安定して運転が可能であるとともに、白金系の電極触媒層を形成した場合にも、電気分解の開始時から電気分解電圧が安定しており、電解槽の安定した運転が可能である。 The electrode substrate of the present invention has a high corrosion resistance of the layer formed on the nickel surface and is not destroyed by a reverse current generated during electrolysis. The aqueous solution electrolysis cathode in which the electrode catalyst layer is formed on the electrode substrate has a low hydrogen overvoltage, and the nickel on the surface of the nickel base does not elute even when energization is stopped. Even when it is used as an electrode, the amount of nickel deposited in the ion exchange membrane is small and stable operation is possible for a long time. Therefore, the electrolysis voltage is stable, and stable operation of the electrolytic cell is possible.
Claims (15)
ニッケル表面を有する導電性基材表面に、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層が形成されていることを特徴とする電極基体。 An electrode substrate for forming an electrode catalyst layer,
An electrode substrate, wherein a mixed layer containing metallic nickel, nickel oxide and carbon atoms is formed on the surface of a conductive substrate having a nickel surface.
前記導電性基材表面に形成され、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層と、
前記混在層表面に形成され、白金族の金属または白金族の金属化合物を含有する電極触媒層と
を備えることを特徴とする水溶液電気分解用陰極。 A conductive substrate having a nickel surface;
Formed on the surface of the conductive substrate, a mixed layer containing nickel metal, nickel oxide and carbon atoms, and
An electrode catalyst layer formed on the surface of the mixed layer and containing a platinum group metal or a platinum group metal compound ;
A cathode for aqueous electrolysis, comprising:
ニッケル表面を有する導電性基材表面に、ニッケル原子、炭素原子、酸素原子、水素原子からなるニッケル化合物を塗布し、酸素含有雰囲気において２５０℃から６００℃で熱分解することにより、金属ニッケル、ニッケル酸化物および炭素原子を含む混在層を形成することを特徴とする電極基体の製造方法。 A method of manufacturing an electrode substrate for forming an electrode catalyst layer,
A conductive substrate surface having a nickel surface, a nickel atom, a carbon atom, an oxygen atom, a nickel compound is applied consisting of a hydrogen atom, by thermally decomposing at 600 ° C. from 250 ° C. in an oxygen-containing atmosphere, metallic nickel, nickel A method for producing an electrode substrate, comprising forming a mixed layer containing an oxide and carbon atoms.
前記電極基体の混在層表面に、白金族の金属化合物を含有する電極触媒形成液を塗布し、酸素含有雰囲気において熱分解することによって電極触媒層を形成することを特徴とする水溶液電気分解用陰極の製造方法。 By applying a nickel compound consisting of nickel atoms, carbon atoms, oxygen atoms, and hydrogen atoms to the surface of a conductive substrate having a nickel surface, and thermally decomposing at 250 ° C. to 600 ° C. in an oxygen-containing atmosphere, metallic nickel, nickel Create an electrode substrate by forming a mixed layer containing oxides and carbon atoms ,
A cathode for aqueous electrolysis, characterized in that an electrode catalyst layer is formed by applying an electrode catalyst forming liquid containing a platinum group metal compound to the mixed layer surface of the electrode substrate and thermally decomposing it in an oxygen-containing atmosphere. Manufacturing method.
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| US10472723B2 (en) | 2015-01-06 | 2019-11-12 | Thyssenkrupp Uhde Chlorine Engineers (Japan) Ltd. | Method of preventing reverse current flow through an ion exchange membrane electrolyzer |
| US10669640B2 (en) | 2015-08-21 | 2020-06-02 | Korea Institute Of Science And Technology | Ultral-low loading of Pt-decorated Ni electrocatalyst, manufacturing method of the same and anion exchange membrane water electrolyzer using the same |
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| CN110791769B (en) * | 2019-11-06 | 2021-08-03 | 南通大学 | Electrode based on halogen salt corrosion and preparation method thereof |
| IT202100020735A1 (en) | 2021-08-02 | 2023-02-02 | Industrie De Nora Spa | ELECTRODE FOR ELECTROLYTIC EVOLUTION OF HYDROGEN |
| IL292647B2 (en) * | 2022-05-01 | 2024-03-01 | Electriq Global Energy Solutions Ltd | A catalyst for generating hydrogen and method of its production |
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| JPS6047352B2 (en) * | 1977-06-27 | 1985-10-21 | 株式会社トクヤマ | Cathode manufacturing method |
| FR2460343A1 (en) * | 1979-06-29 | 1981-01-23 | Solvay | CATHODE FOR THE ELECTROLYTIC PRODUCTION OF HYDROGEN |
| JPS59162288A (en) * | 1983-03-08 | 1984-09-13 | Asahi Chem Ind Co Ltd | Electrode for generating hydrogen |
| JPH0633483B2 (en) * | 1983-07-22 | 1994-05-02 | 旭化成工業株式会社 | Electrode for hydrogen generation |
| JPH022A (en) | 1984-06-20 | 1990-01-05 | Tomio Konno | Method and apparatus for electronic communication with vacuum fiber |
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| DE4342859A1 (en) * | 1993-12-10 | 1995-06-14 | Winsel August | Cathode for hydrogen-generating cell contg. easily incorporated nickel catalyst |
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| US10472723B2 (en) | 2015-01-06 | 2019-11-12 | Thyssenkrupp Uhde Chlorine Engineers (Japan) Ltd. | Method of preventing reverse current flow through an ion exchange membrane electrolyzer |
| US10669640B2 (en) | 2015-08-21 | 2020-06-02 | Korea Institute Of Science And Technology | Ultral-low loading of Pt-decorated Ni electrocatalyst, manufacturing method of the same and anion exchange membrane water electrolyzer using the same |
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| EP2537961A4 (en) | 2016-09-07 |
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