JP2015143388A - Electrode for hydrogen generation, method for producing the same, and method of electrolysis therewith - Google Patents
Electrode for hydrogen generation, method for producing the same, and method of electrolysis therewith Download PDFInfo
- Publication number
- JP2015143388A JP2015143388A JP2014241836A JP2014241836A JP2015143388A JP 2015143388 A JP2015143388 A JP 2015143388A JP 2014241836 A JP2014241836 A JP 2014241836A JP 2014241836 A JP2014241836 A JP 2014241836A JP 2015143388 A JP2015143388 A JP 2015143388A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- hydrogen generation
- hydrogen
- electrolysis
- overvoltage
- 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.)
- Granted
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Landscapes
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Abstract
Description
本発明は水の電気分解又は食塩などのアルカリ金属塩化物水溶液の電気分解に使用する水素発生用電極およびその製造方法並びにこれを用いた電気分解方法に関するものである。 The present invention relates to an electrode for hydrogen generation used for electrolysis of water or electrolysis of an aqueous solution of alkali metal chloride such as salt, a method for producing the same, and an electrolysis method using the same.
水又はアルカリ金属塩化物水溶液電解工業は電力多消費型産業であり、省エネルギー化のために様々な技術開発が行われている。その省エネルギー化の手段とは、理論分解電圧、液抵抗、隔膜抵抗、陽極過電圧、及び、陰極過電圧などで構成される電解電圧を実質的に低減することである。特に、過電圧の低減に関しては、その過電圧値が電極の触媒材料や電極表面のモルフォロジーに左右されることから、その改良についてこれまで多くの研究開発が行われてきた。イオン交換膜法食塩電解においては、陽極過電圧の低減に盛んな研究開発が行われてきた結果、陽極過電圧が低く、耐久性に優れた寸法安定性電極[例えば、ペルメレック電極社製のDSE電極(登録商標)]が完成し、既に食塩電解工業を初め広い電解工業分野で利用されている。 The water or alkali metal chloride aqueous solution electrolysis industry is a power intensive industry, and various technological developments have been made to save energy. The energy saving means is to substantially reduce the electrolysis voltage composed of theoretical decomposition voltage, liquid resistance, diaphragm resistance, anode overvoltage, cathode overvoltage, and the like. In particular, regarding the reduction of the overvoltage, since the overvoltage value depends on the electrode catalyst material and the morphology of the electrode surface, many researches and developments have been conducted on the improvement thereof. As a result of extensive research and development for reducing anode overvoltage in salt exchange electrolysis using an ion exchange membrane method, a dimensional stability electrode having a low anode overvoltage and excellent durability [for example, a DSE electrode manufactured by Permerek Electrode Co., Ltd. ( Registered trademark)] has been completed and has already been used in a wide range of electrolytic industries including the salt electrolysis industry.
一方、陰極過電圧を低減するための水素発生用電極、いわゆる活性陰極に関してもこれまで多くの提案がなされている。一般的に水素過電圧を低下させる手段としては、担持触媒の活性向上と反応比表面積の増加であり、活性向上には、導電性基材上に特定組成の金属混合物、金属合金、金属酸化物あるいはこれらの混合物からなる高活性触媒の担持、比表面積増加はその担持方法により向上させており、主な担持方法としては、触媒成分や金属塩を溶解させた浴から触媒成分を電析させる電気めっき法、金属塩溶液に触媒物質を分散させた浴から触媒成分を電気泳動電着させる分散めっき法、溶融状態の触媒物質を基材に直接溶射する溶射法、金属塩の溶液などを塗布、焼成する熱分解法が挙げられる。 On the other hand, many proposals have been made regarding an electrode for hydrogen generation for reducing cathode overvoltage, so-called active cathode. In general, the means for reducing the hydrogen overvoltage is to increase the activity of the supported catalyst and increase the reaction specific surface area. For the activity improvement, a metal mixture, metal alloy, metal oxide or The loading of highly active catalysts composed of these mixtures and the increase in specific surface area are improved by the loading method. The main loading method is electroplating in which the catalyst components are electrodeposited from a bath in which the catalyst components and metal salts are dissolved. Method, dispersion plating method in which catalyst components are electrophoretically deposited from a bath in which a catalyst material is dispersed in a metal salt solution, thermal spraying method in which a molten catalyst material is directly sprayed onto a substrate, and a metal salt solution is applied and baked. The thermal decomposition method to do is mentioned.
従来、鉄陰極の約400mVという水素過電圧より低い水素過電圧の電極として、例えば、電気めっき法で導電性基材表面に、ニッケルと鉄、コバルト、インジウムとの組み合わせに加えてアミノ酸、カルボン酸、アミンなどの有機化合物を含んだ物質を担持したものが開示されている(特許文献1)。しかし、これらは担持物を非常に厚くすることが必要なため、めっき応力による電極の変形や担持物の剥離が起こりやすいことや、これらの卑金属は活性が低いため、卑金属の合金化による活性向上だけでは水素過電圧を低下させる効果としては不十分なものであった。 Conventionally, as an electrode with a hydrogen overvoltage lower than the hydrogen overvoltage of about 400 mV of an iron cathode, for example, on the surface of a conductive substrate by electroplating, in addition to a combination of nickel, iron, cobalt, and indium, an amino acid, a carboxylic acid, an amine The thing which carry | supported the substance containing organic compounds, such as is disclosed (patent document 1). However, since it is necessary to make the support very thick, the deformation of the electrode due to plating stress and the exfoliation of the support are likely to occur, and the activity of these base metals is low, so the activity is improved by alloying the base metal This alone is not sufficient as an effect of reducing the hydrogen overvoltage.
また、ニッケルとモリブデンからなる合金層をアークイオンプレーティング法で担持したものが開示されている(特許文献2)が、初期水素過電圧は十分低いものの長期電解運転における水素過電圧上昇、いわゆる耐久性に課題があった。 Further, an alloy layer composed of nickel and molybdenum supported by an arc ion plating method is disclosed (Patent Document 2), but the initial hydrogen overvoltage is sufficiently low, but the hydrogen overvoltage rise in long-term electrolysis operation, so-called durability is disclosed. There was a problem.
一方、ニッケルおよび/又はコバルトと、アルミニウム、亜鉛、マグネシウム、シリコンから選ばれる成分、および白金等の貴金属から選ばれる3成分合金からなる水素発生用電極が開示されている(特許文献3)。この電極では、前記3成分からなる合金からアルミニウム、亜鉛、マグネシウム、シリコンから選ばれる成分を溶出・除去しラネー型ニッケルおよび/又はラネー型コバルト触媒を水素発生用電極に使用することを骨子としたもので、貴金属成分をモル比で0.4未満微量添加することによって、ニッケルおよび/又はコバルトが水酸化ニッケルあるいは水酸化コバルトに変質することによる電極活性の劣化を阻止することで耐久性向上を図ったものである。しかし、この電極はニッケルおよび/又はコバルトの比表面積の増加によって水素過電圧を低減しているため、触媒から成分を除去する工程が必要なことや、担持物を数十〜数百μmまで厚くする必要があり、製作コストが非常に高いなどの問題があった。なお、特許文献3には、貴金属成分をモル比で0.4以上にしても、水素発生過電圧の低減効果は無いと記載されている。 On the other hand, an electrode for hydrogen generation comprising nickel and / or cobalt, a component selected from aluminum, zinc, magnesium and silicon and a ternary alloy selected from noble metals such as platinum is disclosed (Patent Document 3). In this electrode, the main point is to use a Raney-type nickel and / or Raney-type cobalt catalyst for the electrode for hydrogen generation by eluting and removing a component selected from aluminum, zinc, magnesium, and silicon from the alloy consisting of the three components. Therefore, by adding a trace amount of noble metal component less than 0.4 by molar ratio, it is possible to improve durability by preventing deterioration of electrode activity caused by nickel and / or cobalt being transformed into nickel hydroxide or cobalt hydroxide. It is intended. However, since this electrode reduces the hydrogen overvoltage by increasing the specific surface area of nickel and / or cobalt, a step for removing components from the catalyst is necessary, and the support is made thicker to several tens to several hundreds μm. There was a problem that the manufacturing cost was very high. Patent Document 3 describes that even if the molar ratio of the noble metal component is 0.4 or more, there is no effect of reducing the hydrogen generation overvoltage.
この他に、白金族金属酸化物とNi等の酸化物との混合物や複合酸化物を使用することが従来から提案されてきた。例えば、特許文献4には、白金族金属化合物とNi等の金属化合物の混合溶液を塗布乾燥してから該金属化合物を酸化するに十分な条件、すなわち、空気や酸素等の酸化性気流中且つ高温で加熱処理し白金族金属酸化物とNi酸化物等との混合酸化物や複合酸化物からなる電極を製造する方法が提案されている。特許文献4の実施例3には、塩化白金酸と塩化ニッケルと塩化ルテニウムの混合溶液をニッケル基材状に塗布し乾燥した後、470〜480℃で熱分解して製作した白金とニッケルとルテニウムの酸化物が被覆された水素発生用電極が開示されており、特許文献4に記載された熱力学計算による実際の絶対再現性電圧から過電圧に換算すると、1週目の過電圧は42mVと十分満足できるものの、電解経過と共に過電圧が上昇しており、6週目の水素発生過電圧は87mV、11週目以降は97mVである。従って、5kA/m2以上の電流密度で使用した場合、過電圧は低くとも100mV以上と予想され、改善すべき課題があった。 In addition, it has been conventionally proposed to use a mixture or composite oxide of a platinum group metal oxide and an oxide such as Ni. For example, Patent Document 4 discloses a condition sufficient to oxidize a metal compound after coating and drying a mixed solution of a platinum group metal compound and a metal compound such as Ni, that is, in an oxidizing air current such as air or oxygen and There has been proposed a method for producing an electrode made of a mixed oxide or composite oxide of platinum group metal oxide and Ni oxide by heat treatment at a high temperature. In Example 3 of Patent Document 4, platinum, nickel, and ruthenium produced by applying a mixed solution of chloroplatinic acid, nickel chloride, and ruthenium chloride to a nickel base material, drying, and then thermally decomposing at 470-480 ° C. An electrode for hydrogen generation coated with an oxide is disclosed, and when converted from an actual absolute reproducibility voltage by thermodynamic calculation described in Patent Document 4 to an overvoltage, the overvoltage in the first week is sufficiently satisfied as 42 mV. Although it is possible, the overvoltage increases with the progress of electrolysis, and the hydrogen generation overvoltage at the 6th week is 87 mV, and after the 11th week is 97 mV. Therefore, when used at a current density of 5 kA / m 2 or more, the overvoltage is expected to be 100 mV or more at least, and there is a problem to be improved.
一方、上記の他にも、貴金属族元素と卑金属元素を複数組み合わせた水素発生用電極が従来から提案されている。例えば、特許文献5には、1種類の貴金属又は2種類若しくは3種類以上の貴金属の混合物若しくは合金からなる貴金属沈着物や、該貴金属沈着物にNi等の1種類又は2種類以上の卑金属を含んだ沈着物をNi等の導電性基材上に沈着させた水素発生用電極が提案されている。しかし、これらの水素発生用電極は、電解液中の鉄等の不純物による被毒を受け易いという課題を持つことが知られている(特許文献6)。 On the other hand, in addition to the above, an electrode for hydrogen generation in which a plurality of noble metal group elements and base metal elements are combined has been proposed. For example, Patent Document 5 includes a noble metal deposit made of one kind of noble metal or a mixture or alloy of two or more kinds of noble metals, and one kind or two or more kinds of base metals such as Ni in the noble metal deposit. There has been proposed an electrode for hydrogen generation in which a deposit is deposited on a conductive substrate such as Ni. However, it is known that these hydrogen generating electrodes have a problem that they are easily poisoned by impurities such as iron in the electrolytic solution (Patent Document 6).
この様に、従来から、貴金属を担持して成る水素過電圧が低い水素発生用電極が提案されているが、白金を担持して成る水素発生用電極は電解液中に存在する微量の鉄イオンに対して敏感に被毒の影響を受け易く鉄イオン濃度が1ppm以下の微量濃度でも水素過電圧は上昇するため、電解液中に鉄イオンが混入しやすいアルカリ金属塩化物水溶液の電気分解工業等での使用に更なる改善が検討されている。 As described above, a hydrogen generating electrode supporting a noble metal and having a low hydrogen overvoltage has been proposed. However, the hydrogen generating electrode supporting platinum is used to reduce the amount of iron ions present in the electrolyte. On the other hand, the hydrogen overvoltage rises even if it is sensitive to poisoning and the iron ion concentration is 1ppm or less, so in the electrolysis industry of alkali metal chloride aqueous solution in which iron ions are likely to be mixed into the electrolyte. Further improvements in use are being considered.
そのため、電解液中の鉄イオンによる被毒防止を目的に幅広く検討が成され、様々な提案が成されている。例えば、低い水素過電圧を有する水素発生陰極をアルカリ金属塩化物水溶液の電気分解に用いた場合の、該陰極上への鉄の析出と陰極液中の鉄イオンとの関係を検討し、陰極液中の鉄イオン濃度が0.5ppm以下の場合には鉄の析出が防止可能であることを見出し、低水素過電圧陰極を用い、且つ、陰極液中の鉄イオン濃度を0.5ppm以下に維持しながら電解するアルカリ金属塩化物水溶液の電気分解方法が提案されて
いる(特許文献6)。かかる発明により、鉄イオンに対して敏感に被毒の影響を受ける水素発生用電極も、アルカリ金属塩化物水溶液の電気分解工業等での使用が可能になった。しかし、特許文献6の提案を実施するためには、陰極液に接する部分の少なくとも陽分極される箇所に高Ni系ステンレス或いはNi等の材料を用いたり、停止時に防食電流を流したりする等が必要であり、経済的観点から改善すべき課題があった。
Therefore, extensive studies have been made for the purpose of preventing poisoning due to iron ions in the electrolyte, and various proposals have been made. For example, when a hydrogen generating cathode having a low hydrogen overpotential is used for electrolysis of an alkali metal chloride aqueous solution, the relationship between iron deposition on the cathode and iron ions in the catholyte is studied. The iron ion concentration of 0.5 ppm or less is found to be able to prevent the precipitation of iron, using a low hydrogen overvoltage cathode, while maintaining the iron ion concentration in the catholyte to 0.5 ppm or less An electrolysis method of an alkaline metal chloride aqueous solution to be electrolyzed has been proposed (Patent Document 6). According to this invention, an electrode for hydrogen generation that is sensitively affected by poisoning to iron ions can be used in the electrolysis industry of an alkali metal chloride aqueous solution. However, in order to implement the proposal of Patent Document 6, it is necessary to use a material such as high Ni-based stainless steel or Ni at least at a portion that is positively polarized in the portion in contact with the catholyte, or to pass an anticorrosion current when stopped. There was a problem that was necessary and should be improved from an economic point of view.
また、鉄イオンにより過電圧が上昇した水素発生用電極から鉄を除去する方法が検討され、鉄の析出で水素過電圧が悪化した水素発生用電極から鉄を除去し再利用する提案が成されてきた。例えば、表面上に析出された鉄と反応し、且つそれを可溶化する液体媒体と接触させることからなる陰極表面に析出された鉄を除去する方法が提案された(特許文献7)。この方法を用いることにより、鉄イオンにより過電圧が上昇した水素発生用電極の再利用が可能となったが、当該提案を実施するためには電気分解を頻繁に停止する必要があり、長期間連続で安定に操業することが出来ない。従って、この場合も経済的観点から改善すべき課題があった。 In addition, a method for removing iron from the hydrogen generating electrode whose overvoltage has increased due to iron ions has been studied, and proposals have been made to remove iron from the hydrogen generating electrode whose hydrogen overvoltage has deteriorated due to iron precipitation and reuse it. . For example, there has been proposed a method for removing iron deposited on the cathode surface by reacting with iron deposited on the surface and bringing it into contact with a solubilizing liquid medium (Patent Document 7). By using this method, it became possible to reuse the hydrogen generating electrode whose overvoltage increased due to iron ions, but in order to implement the proposal, it was necessary to frequently stop the electrolysis, It is not possible to operate stably. Therefore, in this case as well, there was a problem to be improved from an economic viewpoint.
さらに、水素発生用電極自体に鉄イオンが付着しがたい、或いは、付着しても性能が劣化しない特性を付与するための試みが従来から広く行われてきた。例えば、白金およびルテニウムと、金又は銀の少なくとも一方を含む触媒、或いは、さらに有機ポリマーの粒子を含む触媒を導電性基材に担持した水素発生用電極が提案された(特許文献8)。該水素発生用電極は陰極液中に鉄イオンが存在しても過電圧の上昇は極僅かであり、アルカリ金属塩化物水溶液の電気分解のエネルギー使用量を削減しうる点においては確かに優れた特性を有する水素発生用電極である。しかし、白金、金および銀は何れも高価な材料であり、これにポリテトラフルオロエチレンを含ませる場合は、なお一層、高価となる。従って、この場合もなお、経済的観点から改善すべき課題があった。 Furthermore, attempts have been widely made in the past for imparting characteristics in which iron ions are difficult to adhere to the hydrogen generating electrode itself, or the performance does not deteriorate even if it is attached. For example, a hydrogen generation electrode in which a catalyst containing platinum and ruthenium and at least one of gold or silver, or a catalyst containing organic polymer particles is supported on a conductive substrate has been proposed (Patent Document 8). The electrode for hydrogen generation has an excellent characteristic in that the increase in overvoltage is negligible even when iron ions are present in the catholyte, and the amount of energy used for the electrolysis of the alkali metal chloride aqueous solution can be reduced. An electrode for hydrogen generation having However, platinum, gold, and silver are all expensive materials, and when polytetrafluoroethylene is included in them, the cost becomes even more expensive. Therefore, there was still a problem to be improved from an economic viewpoint.
一方、白金とセリウムからなる触媒を用いた水素発生用電極が提案されている(特許文献9)。当該白金とセリウムの触媒からなる水素発生用電極は、過電圧が低く且つ鉄イオンによる影響は抑制され、アルカリ金属塩化物水溶液の電気分解用の水素発生用電極として優れた性能を示す。またさらに、白金およびセリウムに加え、ランタンとルテニウムの4成分を必須とする触媒層を用いた水素発生用電極が提案されている(特許文献10、11)。当該白金およびセリウムとランタンとルテニウムからなる触媒を用いた水素発生用電極は、白金とセリウムのみからなる触媒を用いた水素発生用電極に比べ、水素過電圧は同等、もしくは5mV低下し、且つ、1日1時間電解を停止させながら、10日の連続した電解でも水素過電圧が変わらず、触媒の消耗がなく、電極表面への付着物がないという優れた性能を持つ。 On the other hand, an electrode for hydrogen generation using a catalyst composed of platinum and cerium has been proposed (Patent Document 9). The electrode for hydrogen generation comprising the platinum and cerium catalyst has a low overvoltage and the influence of iron ions is suppressed, and exhibits excellent performance as a hydrogen generation electrode for electrolysis of an aqueous alkali metal chloride solution. Furthermore, an electrode for hydrogen generation using a catalyst layer in which four components of lanthanum and ruthenium are essential in addition to platinum and cerium has been proposed (Patent Documents 10 and 11). The hydrogen generation electrode using the platinum and the catalyst made of cerium, lanthanum, and ruthenium has a hydrogen overvoltage equivalent to or 5 mV lower than the hydrogen generation electrode using the catalyst made only of platinum and cerium, and 1 Even when electrolysis is stopped for 1 hour per day, the hydrogen overvoltage does not change even after 10 days of continuous electrolysis, the catalyst is not consumed, and there is no deposit on the electrode surface.
他に、触媒層内にルテニウム有する水素発生用陰極としては、硝酸ルテニウムとランタンのカルボン酸塩を塗布材料として作製した触媒層(特許文献12)、ルテニウム化合物とセリウム化合物の混合物をシュウ酸の存在下で熱分解することにより得られた組成物を含む水素発生用陰極(特許文献13)、酸化ルテニウムを含むニッケルめっき浴中での電解めっきにより、ニッケルと酸化ルテニウムによるめっき層を形成させ、さらにその上層に熱分解によりセリウムおよびランタンの金属又は金属酸化物からなる層を積層させた水素発生用電極(特許文献14)がある。 In addition, as a cathode for hydrogen generation having ruthenium in the catalyst layer, a catalyst layer (Patent Document 12) produced using a ruthenium nitrate and lanthanum carboxylate coating material, a mixture of a ruthenium compound and a cerium compound is present in the presence of oxalic acid. A cathode for hydrogen generation containing a composition obtained by thermal decomposition under the following conditions (Patent Document 13), and forming a plating layer of nickel and ruthenium oxide by electrolytic plating in a nickel plating bath containing ruthenium oxide; There is a hydrogen generating electrode (Patent Document 14) in which a layer made of a metal or a metal oxide of cerium and lanthanum is laminated by thermal decomposition.
また、鉄イオンの被毒の影響が小さい水素発生用電極として、ニッケル、コバルト、銅、銀および鉄の群から選ばれる一種の金属と白金からなる白金合金、あるいは遷移金属元素と白金との非晶質物質からなる水素発生電極が提案されている(特許文献15)。 In addition, as an electrode for hydrogen generation that is less affected by iron ion poisoning, a platinum alloy composed of one kind of metal selected from the group consisting of nickel, cobalt, copper, silver and iron, or a non-transition metal element and platinum. A hydrogen generating electrode made of a crystalline material has been proposed (Patent Document 15).
しかしながら、鉄イオンの被毒の影響がまだ大きく、逆電流耐性が十分でなく、水素発生電極の更なる改良が望まれている。 However, the influence of iron ion poisoning is still large and the reverse current resistance is not sufficient, and further improvement of the hydrogen generating electrode is desired.
以上述べてきた通り、水又はアルカリ金属塩化物水溶液電解工業の電力消費量を削減する目的で、従来から様々な水素発生用電極および水素発生用電極の使用方法が提案されてきたが、従来の水素発生用電極は水素過電圧特性と、陰極液中の鉄イオンに対する耐被毒性能や起動・停止を余儀なくされる工業的な使用において十分な耐久性を兼ね備え、工業的に満足し得る特性を持つ水素発生用電極は、依然得られていなかった。 As described above, for the purpose of reducing the power consumption of the water or alkali metal chloride aqueous solution electrolysis industry, various hydrogen generating electrodes and methods for using the hydrogen generating electrodes have been proposed. The electrode for hydrogen generation combines the characteristics of hydrogen overvoltage, anti-poisoning performance against iron ions in the catholyte, and sufficient durability for industrial use that requires starting and stopping, and has industrially satisfactory characteristics. An electrode for hydrogen generation has not been obtained.
本発明の目的は、水又はアルカリ金属塩化物水溶液電解工業等で使用可能な、水素過電圧が十分に低く、且つ、鉄イオンによる被毒の影響がなく、さらに、運転中や起動・停止中にも水素過電圧の上昇や担持物の脱落がなく、耐久性に優れた水素発生用電極、該水素発生電極の製造方法、並びに、該水素発生用電極を陰極に用いた電解方法を提供し、水又はアルカリ金属塩化物水溶液電解工業等の電力消費量を削減することにある。特に、熱分解による、白金とニッケル等の遷移金属からなる触媒が担持されて成る水素発生用活性陰極の改良を図り、水素過電圧が低く、且つ、鉄イオンによる被毒耐性や電解運転中や停止・起動操作中に流れる逆電流への耐性を向上させ、電極耐久性が向上した水素発生用電極を提供することにある。 The purpose of the present invention is that it can be used in water or alkali metal chloride aqueous solution electrolysis industry, etc., and the hydrogen overvoltage is sufficiently low and there is no influence of poisoning by iron ions. In addition, there is provided a hydrogen generating electrode excellent in durability without an increase in hydrogen overvoltage or dropping of the support, a method for producing the hydrogen generating electrode, and an electrolysis method using the hydrogen generating electrode as a cathode. Or it is to reduce the power consumption of the alkali metal chloride aqueous solution electrolysis industry or the like. In particular, by improving the active cathode for hydrogen generation, which is supported by a catalyst composed of transition metals such as platinum and nickel, by thermal decomposition, the hydrogen overvoltage is low, the poisoning resistance by iron ions, and the electrolysis operation is stopped or stopped. -To provide an electrode for hydrogen generation with improved resistance to reverse current flowing during start-up operation and improved electrode durability.
本発明は、導電性基材上に、白金、ニッケルおよびルテニウムを主成分とする触媒層が担持されてなる水素発生用電極に関するものである。 The present invention relates to an electrode for hydrogen generation in which a catalyst layer mainly composed of platinum, nickel and ruthenium is supported on a conductive substrate.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
導電性基材上に、白金、ニッケルおよびルテニウムからなる触媒層が担持された水素発生用電極は、例えば、導電性基材上に、白金化合物溶液とニッケル化合物溶液とルテニウム化合物溶液を塗布し、200℃以下の温度で乾燥し、その後200℃を超え700℃以下の温度で熱分解して得られた触媒層前駆体の還元処理により触媒層を形成することにより得られ、還元後の触媒層中には、白金とニッケルとルテニウムの合金が形成されている。前記触媒層は水素発生用電極として優れた性能を有する。 An electrode for hydrogen generation in which a catalyst layer made of platinum, nickel, and ruthenium is supported on a conductive substrate, for example, a platinum compound solution, a nickel compound solution, and a ruthenium compound solution are applied on the conductive substrate, A catalyst layer after reduction obtained by forming a catalyst layer by reduction treatment of a catalyst layer precursor obtained by drying at a temperature of 200 ° C. or lower and then pyrolyzing at a temperature of more than 200 ° C. and less than 700 ° C. Inside, an alloy of platinum, nickel and ruthenium is formed. The catalyst layer has excellent performance as an electrode for hydrogen generation.
尚、還元後の触媒層中の白金とニッケルとルテニウムの合金の割合について、詳細は不明であるが、X線回折結果によれば、大部分が白金とニッケルとルテニウムの合金であり、一部、酸化ルテニウムや酸化ニッケルとして残存し、X線ピークが存在しないアモルファス金属、または、水またはアルカリ金属水酸化物水溶液中での長時間の電解後には、白金、ニッケル及びルテニウム合金の表面上に水酸化物が形成されている可能性もあると考える。 The details of the ratio of platinum, nickel, and ruthenium alloy in the catalyst layer after reduction are unknown, but according to the X-ray diffraction results, most of the alloy is platinum, nickel, and ruthenium. After the electrolysis for a long time in an amorphous metal that remains as ruthenium oxide or nickel oxide and does not have an X-ray peak, or in an aqueous solution of water or alkali metal hydroxide, water on the surface of platinum, nickel, and ruthenium alloy It is considered that an oxide may be formed.
また、水素過電圧が低く、逆電流耐性も優れているため、触媒層中のルテニウムの含有量は、1モル%以上55モル%以下が好ましく、1モル%以上33モル%以下の範囲が好ましく、水素過電圧が低いだけでなく、逆電流耐性にも優れているため、触媒層中のルテニウム含有量が20〜50モル%、ニッケル含有量が40〜25モル%、残部が白金であることが好ましく、触媒層中のルテニウム含有量が20〜32モル%、ニッケル含有量が40〜34モル%、残部が白金であることが好ましい。 Further, since the hydrogen overvoltage is low and the reverse current resistance is excellent, the ruthenium content in the catalyst layer is preferably 1 mol% or more and 55 mol% or less, preferably 1 mol% or more and 33 mol% or less, Since not only the hydrogen overvoltage is low but also the reverse current resistance is excellent, it is preferable that the ruthenium content in the catalyst layer is 20 to 50 mol%, the nickel content is 40 to 25 mol%, and the balance is platinum. The ruthenium content in the catalyst layer is preferably 20 to 32 mol%, the nickel content is 40 to 34 mol%, and the balance is platinum.
さらに、上記還元処理については、電気化学的還元であることが好ましく、水又はアルカリ金属塩化物水溶液を電気分解するときの電気化学的還元であることがより好ましい。 Furthermore, the reduction treatment is preferably electrochemical reduction, and more preferably electrochemical reduction when electrolyzing water or an aqueous alkali metal chloride solution.
本発明で用いる導電性基材は、例えばニッケル、鉄、銅、チタンやステンレス合金鋼が挙げられ、特にアルカリ性溶液に対して耐食性の優れたニッケルが好ましい。導電性基材の形状は、特に限定されるものではなく、一般に電解槽の電極に合せた形状でよく、例えば平板、曲板等が使用可能である。 Examples of the conductive substrate used in the present invention include nickel, iron, copper, titanium, and stainless steel alloy, and nickel having excellent corrosion resistance against an alkaline solution is particularly preferable. The shape of the conductive substrate is not particularly limited, and may generally be a shape that matches the electrode of the electrolytic cell. For example, a flat plate, a curved plate, or the like can be used.
また、本発明で用いる導電性基材は、多孔板が好ましく、例えば、エキスパンドメタル、パンチメタル、網等が使用できる。 In addition, the conductive substrate used in the present invention is preferably a perforated plate, and for example, expanded metal, punch metal, and net can be used.
本発明の水素発生用電極を製造する方法は、導電性基材上に、白金とニッケルとルテニウムからなる触媒層を担持することが出来ればどの様な製造方法でもよい。例えば、電気めっき法、分散めっき法、溶射法、熱分解法、アークイオンプレーティング法などを用いることができる。しかし、これらの既知の製造方法を用いる場合、導電性基材上に白金とニッケルとルテニウムからなる触媒層を担持するためには、製造条件や原料を鋭意検討し設定する必要がある。単に既知の製造方法を適用しただけでは、本発明が提供する、導電性基材上に、白金とニッケルとルテニウムからなる触媒層を担持した水素発生用電極を製造することは出来ない。 The method for producing the electrode for hydrogen generation of the present invention may be any production method as long as a catalyst layer made of platinum, nickel and ruthenium can be supported on a conductive substrate. For example, an electroplating method, a dispersion plating method, a thermal spraying method, a thermal decomposition method, an arc ion plating method, or the like can be used. However, when using these known production methods, it is necessary to intensively study and set production conditions and raw materials in order to support a catalyst layer made of platinum, nickel, and ruthenium on a conductive substrate. By simply applying a known production method, it is not possible to produce a hydrogen generating electrode provided with a catalyst layer made of platinum, nickel and ruthenium on a conductive substrate provided by the present invention.
以下、本発明が提供する、導電性基材上に、白金とニッケルとルテニウムからなる触媒層を担持した水素発生用電極を製造する具体的方法を、熱分解法を例に説明する。 Hereinafter, a specific method for producing an electrode for hydrogen generation provided with a catalyst layer made of platinum, nickel and ruthenium on a conductive substrate provided by the present invention will be described by taking a thermal decomposition method as an example.
本発明で言う熱分解法とは、基材上に、白金化合物溶液とニッケル化合物溶液とルテニウム化合物溶液を塗布し、乾燥し、熱分解を行う一連の操作を言う。 The thermal decomposition method referred to in the present invention refers to a series of operations in which a platinum compound solution, a nickel compound solution, and a ruthenium compound solution are applied onto a substrate, dried, and thermally decomposed.
導電性基材は、予め基材表面を粗面化することが好ましい。これは、粗面化によって接触表面積を大きくでき、基材と担持物の密着性が向上するためである。粗面化の手段としては特に限定されず、公知の方法、例えばサンドブラスト処理、蓚酸、塩酸溶液などによりエッチング処理し、水洗、乾燥する方法を用いることができる。 The conductive substrate is preferably roughened in advance. This is because the contact surface area can be increased by roughening, and the adhesion between the substrate and the support is improved. The surface roughening means is not particularly limited, and a known method such as sand blasting, etching with oxalic acid or hydrochloric acid solution, washing with water and drying can be used.
本発明の水素発生用電極の製造方法に用いる白金化合物は、塩化白金酸、ジニトロジアミン白金などを用いることができる。特にアンミン錯体を形成するジニトロジアンミン白金を用いると、還元処理後の白金合金の結晶子径を例えば200オングストローム以下まで微細化し、反応比表面積を増大させられるため好ましい。これは、前記ジニトロジアミン白金は熱分解温度が約550℃と高いために、熱分解中の白金の凝集を抑制し、熱分解後に白金とニッケルとルテニウムが均一に混合した被膜が得られ、還元処理により微細な結晶子径の合金が得られるためと推定される。 As the platinum compound used in the method for producing an electrode for hydrogen generation of the present invention, chloroplatinic acid, dinitrodiamineplatinum and the like can be used. In particular, it is preferable to use dinitrodiammine platinum that forms an ammine complex because the crystallite diameter of the platinum alloy after the reduction treatment can be reduced to, for example, 200 angstroms or less to increase the reaction specific surface area. This is because the thermal decomposition temperature of the dinitrodiamine platinum is as high as about 550 ° C., so that aggregation of platinum during thermal decomposition is suppressed, and a film in which platinum, nickel and ruthenium are uniformly mixed after thermal decomposition is obtained. It is presumed that an alloy having a fine crystallite diameter can be obtained by the treatment.
一方、本発明の製造方法に用いるニッケル化合物およびルテニウム化合物としては特に限定されず、硝酸塩、硫酸塩、塩化物、炭酸塩、酢酸塩、スルファミン酸塩などを用いることができる。 On the other hand, nickel compounds and ruthenium compounds used in the production method of the present invention are not particularly limited, and nitrates, sulfates, chlorides, carbonates, acetates, sulfamates, and the like can be used.
さらに、白金化合物とニッケル化合物とルテニウム化合物を溶解させる場合の溶媒としては、担持物の表面積を高めるためには、これらの原料が完全に溶解できるものが好ましく、水あるいは硝酸、塩酸、硫酸、酢酸溶液などの無機酸、さらにメタノール、エタノール、プロパノール、ブタノールなどの有機溶媒、あるいはこれらを混合物として用いることもできる。また、塗布液中へ基材金属の溶解を抑制する目的で塗布液のpHを調製して用いてもよく、担持物の表面積を高めるためにリシン、クエン酸などの錯塩を添加し、ニッケルおよびルテニウムを錯体化させてもよい。 Further, as a solvent for dissolving the platinum compound, nickel compound and ruthenium compound, in order to increase the surface area of the support, those which can completely dissolve these raw materials are preferable, and water or nitric acid, hydrochloric acid, sulfuric acid, acetic acid are preferable. An inorganic acid such as a solution, an organic solvent such as methanol, ethanol, propanol, or butanol, or a mixture thereof can also be used. In addition, the pH of the coating solution may be adjusted and used for the purpose of suppressing dissolution of the base metal in the coating solution, and a complex salt such as lysine or citric acid may be added to increase the surface area of the support, and nickel and Ruthenium may be complexed.
前記化合物溶液を導電性基材に塗布する方法は、白金化合物溶液とニッケル化合物溶液とルテニウム化合物溶液を別々に刷毛などを用いて導電性基材に塗布してもよいし、白金化合物とニッケル化合物とルテニウム化合物の混合溶液を調製し、刷毛などを用いて導電性基材に塗布してもよい。また、前記の刷毛塗り以外にスプレー法、ディップコート法など、全ての既知の方法を好適に用いることができる。 The compound solution may be applied to the conductive substrate by separately applying the platinum compound solution, the nickel compound solution, and the ruthenium compound solution to the conductive substrate using a brush or the like, or the platinum compound and the nickel compound. Alternatively, a mixed solution of ruthenium compound may be prepared and applied to the conductive substrate using a brush or the like. In addition to the above brush coating, all known methods such as a spray method and a dip coating method can be suitably used.
塗布後の乾燥温度は200℃以下の温度で5〜60分間行えばよく、150℃以下の乾燥温度が好ましい。 The drying temperature after application may be 5 to 60 minutes at a temperature of 200 ° C. or lower, and a drying temperature of 150 ° C. or lower is preferable.
乾燥後の熱分解温度は200℃を超え700℃以下の範囲で5〜60分間行えばよいが、好ましくは350℃を超え500℃以下の範囲で行うとよい。例えば、ジニトロジアミン白金溶液を用いた場合、ジニトロジアミン白金の熱分解温度は550℃であり、500℃以下で熱分解を行うことで白金のシンタリングが抑制され、水素過電圧がより一層低い水素発生用電極を得ることができる。 The thermal decomposition temperature after drying may be performed for 5 to 60 minutes in the range of over 200 ° C. and 700 ° C. or less, but preferably over 350 ° C. and 500 ° C. or less. For example, when a dinitrodiamine platinum solution is used, the thermal decomposition temperature of dinitrodiamine platinum is 550 ° C., and by performing thermal decomposition at 500 ° C. or less, platinum sintering is suppressed and hydrogen overvoltage is further reduced. A working electrode can be obtained.
上記の塗布、乾燥、および熱分解の一連の操作を1回又は数回繰り返す。熱分解操作を繰り返す回数は特に限定されないが、低い水素過電圧を得るためには還元処理後の合金の担持量で0.5g/m2以上となるまで熱分解操作を繰り返すことが好ましく、1g/m2以上となるまで熱分解操作を繰り返すことがさらに好ましい。 The above series of operations of application, drying, and thermal decomposition is repeated once or several times. The number of times of repeating the pyrolysis operation is not particularly limited, but in order to obtain a low hydrogen overvoltage, it is preferable to repeat the pyrolysis operation until the supported amount of the alloy after the reduction treatment is 0.5 g / m 2 or more. More preferably, the pyrolysis operation is repeated until m 2 or more.
熱分解した後、担持物(触媒層前駆体)を金属状態に還元、合金化させることを目的とした還元処理を行う。還元処理方法は特に限定されないが、ヒドラジン、ギ酸、蓚酸などの還元力の強い物質との接触による化学還元法、白金とニッケルとルテニウムに対し、還元電位を与える電気化学還元法を用いることができる。 After thermal decomposition, a reduction treatment is performed for the purpose of reducing and alloying the support (catalyst layer precursor) to a metallic state. Although the reduction treatment method is not particularly limited, a chemical reduction method by contact with a substance having a strong reducing power such as hydrazine, formic acid, or oxalic acid, or an electrochemical reduction method that gives a reduction potential to platinum, nickel, and ruthenium can be used. .
例えば、電気化学還元法は白金とニッケルとルテニウムからなる担持物(触媒層前駆体)の還元に必要な電位を与える方法である。水溶液中の白金とニッケルとルテニウムの標準電極電位はすでに開示されており(「電気化学便覧」 第5版 丸善出版 第92〜95頁)、還元に必要な電位は標準電極電位から見積もることが可能である。 For example, the electrochemical reduction method is a method of applying a potential necessary for the reduction of a support (catalyst layer precursor) made of platinum, nickel, and ruthenium. The standard electrode potentials of platinum, nickel, and ruthenium in aqueous solution have already been disclosed ("Electrochemical Handbook" 5th edition, Maruzen Publishing, pages 92-95), and the potential required for reduction can be estimated from the standard electrode potential. It is.
熱分解後の担持物(触媒層前駆体)を金属状態に還元、合金化させるにあたり、電気化学的還元法が、電解をしながら熱分解後の担持物(触媒層前駆体)を金属状態に還元、合金化が実施でき、電解とは別に上記担持物還元処理をしなくても済むので、便利である。 In reducing and alloying the support (catalyst layer precursor) after pyrolysis to a metal state, the electrochemical reduction method converts the support (catalyst layer precursor) after pyrolysis to a metal state while performing electrolysis. This is convenient because reduction and alloying can be carried out, and it is not necessary to carry out the above-mentioned support reduction treatment separately from electrolysis.
この電気化学的還元処理は、通常、水又はアルカリ金属塩化物水溶液中での電気化学的還元処理で実施される。 This electrochemical reduction treatment is usually performed by an electrochemical reduction treatment in water or an aqueous alkali metal chloride solution.
この様にして得られる本発明の水素発生用電極は、水又は食塩などのアルカリ金属塩化物水溶液の電気分解用途において水素発生用電極として用いると、低水素過電圧が得られると共に、陰極液中に鉄イオンを混入させない特別な工夫をすることなく低過電圧特性を長期間安定に維持し、且つ、停止や再起動操作時に触媒が剥離や脱落を生じることもない、すなわち、水素過電圧性能と耐久性に極めて優れた水素発生用電極である。 The electrode for hydrogen generation of the present invention thus obtained can be used as an electrode for hydrogen generation in electrolysis of an aqueous solution of alkali metal chloride such as water or sodium chloride, and a low hydrogen overvoltage can be obtained. Low overvoltage characteristics can be maintained stably for a long time without any special measures not to incorporate iron ions, and the catalyst will not peel off or fall off during a stop or restart operation, that is, hydrogen overvoltage performance and durability It is an excellent electrode for hydrogen generation.
従って、水又は食塩などのアルカリ金属塩化物水溶液の電気分解工業分野において、水素発生用電極を本発明が提供する水素発生用電極に変更するのみで、当該電気分解工業の所要エネルギーを容易に低減可能となる。 Therefore, in the field of electrolysis industry of aqueous solutions of alkali metal chlorides such as water or salt, the required energy of the electrolysis industry can be easily reduced simply by changing the electrode for hydrogen generation to the electrode for hydrogen generation provided by the present invention. It becomes possible.
尚、水又は食塩などのアルカリ金属塩化物水溶液の電気分解工業とは、水素発生用電極を陰極として使用し、隔膜を挟んで陽極を配置した電解槽で水又はアルカリ金属塩化物水溶液を電気分解し、前記陰極上から水素ガスおよびアルカリ金属水酸化物水溶液を生成し、陽極上から酸素ガス又は塩素ガスを生成する所謂、食塩電解が代表的な電気分解工業の例である。 In addition, electrolysis industry of alkali metal chloride aqueous solution such as water or salt uses water generating electrode as a cathode and electrolyzes water or alkali metal chloride aqueous solution in an electrolytic cell in which an anode is placed across a diaphragm. So-called salt electrolysis, in which hydrogen gas and an aqueous alkali metal hydroxide solution are generated from the cathode and oxygen gas or chlorine gas is generated from the anode, is a typical example of the electrolysis industry.
その隔膜として、電流効率や低い電解槽電圧によるエネルギー効率の面で、陽イオン交換膜を使用することが好ましい。 As the diaphragm, a cation exchange membrane is preferably used in terms of current efficiency and energy efficiency due to a low electrolytic cell voltage.
本発明の導電性基材上に、白金、ニッケルおよびルテニウムを主成分とする触媒層が担持されてなる水素発生用電極は、低い水素過電圧性能を有し、且つ、耐久性に優れた水素発生用電極であり、その電極は、導電性基板上に触媒層前駆体を形成後、還元処理を行い前記触媒層を形成させる簡便な方法により製造可能であり、この様にして得られる本発明の水素発生用電極は、従来の白金系触媒の欠点とされていた電解液中の鉄イオンの被毒によって、水素過電圧が上昇することがなく、さらに、電解運転中や停止・起動操作中に流れる逆電流により触媒が剥離・脱落することもない。そのため、白金が本来有する低水素過電圧特性を長期間に渡り安定に維持でき、特に年間数回の停止、再起動の際に流れる逆電流や陰極液中への鉄混入が余儀なくされる水又はアルカリ金属水溶液の電気分解工業等の所要エネルギーを大幅に削減可能である。 The electrode for hydrogen generation in which a catalyst layer mainly composed of platinum, nickel and ruthenium is supported on the conductive substrate of the present invention has low hydrogen overvoltage performance and excellent hydrogen generation. The electrode can be manufactured by a simple method of forming a catalyst layer precursor on a conductive substrate and then performing a reduction treatment to form the catalyst layer. The electrode for hydrogen generation does not increase the hydrogen overvoltage due to the poisoning of iron ions in the electrolyte, which has been regarded as a drawback of conventional platinum-based catalysts, and further flows during electrolysis operation and stop / start operations. The catalyst does not peel or fall off due to the reverse current. Therefore, the low hydrogen overvoltage characteristic inherent in platinum can be stably maintained over a long period of time, and in particular, water or alkali that is forced to contain iron in the catholyte and reverse current that flows several times a year during shutdown and restart. The energy required for the electrolysis industry of metal aqueous solutions can be greatly reduced.
以下の実施例により、本発明を具体的に説明する。 The following examples illustrate the invention.
尚、各評価は下記に示す方法で実施した。
(水素過電圧測定)
32wt%水酸化ナトリウム水溶液の電解液(容量約1L)を用いて、対極にNi、温度88℃、電流密度6.0kA/m2の条件で10分間、水電解を行い、カレントインタラプター法により、水素過電圧を測定した。
(鉄被毒耐性評価)
上記方法で水素過電圧を測定した後、32wt%水酸化ナトリウム水溶液の電解液(容量約100mL)中に鉄標準液(関東化学株式会社製、Fe:1000mg/l)を添加し鉄濃度が10ppmになるようにし、その電解液中で対極にNi、電流密度6.0kA/m2という条件で2時間水電解をさせ、再び上記方法で水素過電圧を測定し、先に測定した水素過電圧との差を求め、その値を鉄被毒による過電圧上昇値とし、この過電圧上昇値により、鉄被毒耐性評価を実施した。
(逆電流耐性評価)
上記方法で水素過電圧を測定した後、0.5M硫酸ナトリウム中で、対極にPt、参照電極に飽和カロメル電極、走査電位−1.0Vから0.6V vs SCE、走査速度50mV/s、初期電位0.1V vs SCE、サイクル数250サイクルという条件でサイクリックボルタンメトリーを行い、再び上記方法で水素過電圧を測定し、先に測定した水素過電圧との差を求め、その値を逆電流による過電圧上昇値とし、この過電圧上昇値により、逆電流耐性評価を実施した。
In addition, each evaluation was implemented by the method shown below.
(Hydrogen overvoltage measurement)
Water electrolysis was performed for 10 minutes under the conditions of Ni, temperature 88 ° C., and current density 6.0 kA / m 2 using an electrolytic solution of 32 wt% sodium hydroxide aqueous solution (capacity: about 1 L) by the current interrupter method. The hydrogen overvoltage was measured.
(Iron poison resistance evaluation)
After the hydrogen overvoltage was measured by the above method, an iron standard solution (manufactured by Kanto Chemical Co., Fe: 1000 mg / l) was added to an electrolyte solution (capacity: about 100 mL) of a 32 wt% aqueous sodium hydroxide solution to bring the iron concentration to 10 ppm In the electrolyte solution, water was electrolyzed for 2 hours under the conditions of Ni and current density of 6.0 kA / m 2 in the electrolyte solution, and the hydrogen overvoltage was measured again by the above method, and the difference from the previously measured hydrogen overvoltage. The value was used as the overvoltage increase value due to iron poisoning, and the iron poisoning resistance evaluation was performed based on this overvoltage increase value.
(Reverse current tolerance evaluation)
After measuring the hydrogen overvoltage by the above method, in 0.5 M sodium sulfate, Pt as the counter electrode, saturated calomel electrode as the reference electrode, scanning potential -1.0 V to 0.6 V vs SCE, scanning
また、上記方法で水素過電圧を測定したものと、上記方法で水素過電圧の測定の後にサイクリックボルタンメトリー測定を実施し再び水素過電圧を測定したものを、王水で溶解させ、ICP発光分析装置(パーキンエルマー社製、型式optima3000)を用いて担持量を求め、それらの値から白金量の変化率を求め、その値を逆電流による白金の残存率とした。 In addition, the hydrogen overvoltage measured by the above method and the one obtained by performing cyclic voltammetry measurement after the hydrogen overvoltage measurement by the above method and again measuring the hydrogen overvoltage were dissolved in aqua regia, and the ICP emission spectrometer (Perkin The load was determined using Elmer's model optima 3000), and the rate of change in the amount of platinum was determined from these values, which was used as the residual rate of platinum due to the reverse current.
実施例1
導電性基材として、ニッケルエキスパンドメッシュ(5.0×5.0cm)を用い、粗面化処理として、10wt%の塩酸溶液を用いて温度50℃で15分間エッチングした後、水洗、乾燥した。
Example 1
Nickel expanded mesh (5.0 × 5.0 cm) was used as the conductive substrate, and as a roughening treatment, etching was performed at a temperature of 50 ° C. for 15 minutes using a 10 wt% hydrochloric acid solution, followed by washing with water and drying.
次いで、ジニトロジアンミン白金硝酸溶液(田中貴金属製)と硝酸ニッケル6水和物と硝酸ルテニウムの硝酸溶液(田中貴金属製)と水を用いて、白金が34モル%、ニッケルが34モル%とルテニウムが32モル%の塗布液を調製した。 Next, using dinitrodiammine platinum nitric acid solution (Tanaka Kikinzoku), nickel nitrate hexahydrate, ruthenium nitrate nitric acid solution (Tanaka Kikinzoku) and water, platinum was 34 mol%, nickel was 34 mol% and ruthenium was A 32 mol% coating solution was prepared.
触媒層中の白金とニッケルとルテニウムの含有量は、白金化合物溶液とニッケル化合物溶液とルテニウム化合物溶液中の塗布溶液中の白金、ニッケル及びルテニウムの含有量(モル%)で決定される。 The contents of platinum, nickel, and ruthenium in the catalyst layer are determined by the contents (mol%) of platinum, nickel, and ruthenium in the coating solution in the platinum compound solution, the nickel compound solution, and the ruthenium compound solution.
次いで、この塗布液を前記ニッケルエキスパンドメッシュに刷毛を用い全面に塗布し、熱風式乾燥機内で80℃15分間乾燥後、箱型マッフル炉(アドバンテック東洋製 型式KM−600、内容積27L)を用いて空気流通下のもと500℃で15分熱分解した。この一連の操作を5回繰り返した。 Next, this coating solution was applied to the entire surface of the nickel expanded mesh using a brush, dried at 80 ° C. for 15 minutes in a hot air dryer, and then used in a box-type muffle furnace (Advantech Toyo model KM-600, internal volume 27 L). And pyrolyzed at 500 ° C. for 15 minutes under air flow. This series of operations was repeated 5 times.
上記の様に得られた水素発生用電極を、32wt%水酸化ナトリウム水溶液の電解液(容量約1L)を用いて、対極にNi、温度88℃、電流密度6.0kA/m2の条件で10分間、水電解を行った後に、水素発生電極を取り出して、乾燥し、そのX線回折を実施した時のX線回折チャートを図1に示す。 The electrode for hydrogen generation obtained as described above was subjected to the conditions of Ni, temperature 88 ° C., current density 6.0 kA / m 2 at the counter electrode, using an electrolytic solution (capacity: about 1 L) of a 32 wt% sodium hydroxide aqueous solution. After water electrolysis for 10 minutes, the hydrogen generating electrode is taken out, dried, and the X-ray diffraction chart when the X-ray diffraction is performed is shown in FIG.
この図1から、白金とニッケルとルテニウムの合金が主ピークであるが、RuO2及びNiOのピークも存在している事が明らかとなった。 From FIG. 1, it is clear that an alloy of platinum, nickel and ruthenium has a main peak, but peaks of RuO 2 and NiO also exist.
水素過電圧測定を行うと、水素過電圧は74.5mVであり、さらに、鉄被毒による過電圧上昇量は17.8mV、逆電流による過電圧上昇量は2.0mV、逆電流による白金の残存率は100%であった。この結果は表1に示す。 When the hydrogen overvoltage is measured, the hydrogen overvoltage is 74.5 mV, the overvoltage increase due to iron poisoning is 17.8 mV, the overvoltage increase due to the reverse current is 2.0 mV, and the residual rate of platinum due to the reverse current is 100 %Met. The results are shown in Table 1.
実施例2−4
実施例1において、白金、ニッケルとルテニウムの組成をそれぞれ表1に記載の組成とした以外は実施例1と同様の操作で電極を作製した。
Example 2-4
In Example 1, an electrode was produced in the same manner as in Example 1 except that the composition of platinum, nickel, and ruthenium was changed to the composition shown in Table 1, respectively.
実施例2では、水素過電圧測定を行うと水素過電圧は75.7mVであり、さらに、鉄被毒による過電圧上昇量は13.3mV、逆電流による過電圧上昇量は15.9mVであった。この結果は表1に示す。 In Example 2, when the hydrogen overvoltage measurement was performed, the hydrogen overvoltage was 75.7 mV, the overvoltage increase due to iron poisoning was 13.3 mV, and the overvoltage increase due to the reverse current was 15.9 mV. The results are shown in Table 1.
実施例3では、水素過電圧測定を行うと水素過電圧は79.0mVであり、さらに、鉄被毒による過電圧上昇量は14.1mV、逆電流による過電圧上昇量は26.2mVであった。この結果は表1に示す。 In Example 3, when the hydrogen overvoltage measurement was performed, the hydrogen overvoltage was 79.0 mV, the overvoltage increase due to iron poisoning was 14.1 mV, and the overvoltage increase due to the reverse current was 26.2 mV. The results are shown in Table 1.
実施例4では、水素過電圧測定を行うと水素過電圧は73.2mVであり、さらに、鉄被毒による過電圧上昇量は16.0mV、逆電流による過電圧上昇量は12.4mVであった。この結果は表1に示す。 In Example 4, when the hydrogen overvoltage was measured, the hydrogen overvoltage was 73.2 mV, the overvoltage increase due to iron poisoning was 16.0 mV, and the overvoltage increase due to the reverse current was 12.4 mV. The results are shown in Table 1.
比較例1
実施例1において、ジニトロジアンミン白金硝酸溶液と硝酸ニッケル6水和物と水を用いて、白金が50モル%、ニッケルが50モル%の塗布液を調製し、これを塗布した以外は、実施例1と同様の操作で電極を作製した。
Comparative Example 1
In Example 1, except that a coating solution containing 50 mol% platinum and 50 mol% nickel was prepared using a dinitrodiammine platinum nitrate solution, nickel nitrate hexahydrate and water, and this was applied. An electrode was produced in the same manner as in 1.
水素過電圧測定を行うと、水素過電圧は82.9mVであり、さらに、鉄被毒による過電圧上昇量は20.0mV、逆電流による過電圧上昇量は16.4mV、逆電流による白金の残存率は93%であった。この結果は表1に示す。 When the hydrogen overvoltage was measured, the hydrogen overvoltage was 82.9 mV, the overvoltage increase due to iron poisoning was 20.0 mV, the overvoltage increase due to the reverse current was 16.4 mV, and the residual rate of platinum due to the reverse current was 93. %Met. The results are shown in Table 1.
比較例2
実施例1において、ジニトロジアンミン白金硝酸溶液と硝酸ルテニウムの硝酸溶液と水を用いて、白金が50モル%、ルテニウムが50モル%の塗布液を調製し、これを塗布した以外は、実施例1と同様の操作で電極を作製した。
Comparative Example 2
In Example 1, except that a coating solution containing 50 mol% platinum and 50 mol% ruthenium was prepared using a dinitrodiammine platinum nitric acid solution, a ruthenium nitrate nitric acid solution and water, and this was applied. An electrode was produced in the same manner as described above.
水素過電圧測定を行うと、水素過電圧は88.7mVであった。この結果は表1に示す。 When hydrogen overvoltage measurement was performed, the hydrogen overvoltage was 88.7 mV. The results are shown in Table 1.
加えて、すべての実施例において、鉄被毒による過電圧上昇量は比較例1での結果より低い値となり、かつ、実施例1−2において、逆電流による過電圧上昇量は比較例1での結果より低い値となっていた。また、実施例1の白金残存率は比較例1に比べ高い値となっていた。よって、本発明の水素発生用電極は優れた水素過電圧性能と鉄被毒および逆電流に対する耐久性を有することが上記表1に示されている。
In addition, in all Examples, the amount of overvoltage increase due to iron poisoning is lower than the result in Comparative Example 1, and in Example 1-2, the amount of overvoltage increase due to reverse current is the result in Comparative Example 1. It was a lower value. Further, the platinum residual ratio of Example 1 was higher than that of Comparative Example 1. Therefore, it is shown in Table 1 that the hydrogen generating electrode of the present invention has excellent hydrogen overvoltage performance, iron poisoning and durability against reverse current.
この中でも、水素過電圧が低い実施例1〜2および実施例4が好ましく、Ruの含有量が20〜55モル%、Niが40〜34モル%、残部がPtである組成の触媒層が担持されてなる水素発生用電極が好ましい。 Among these, Examples 1-2 and Example 4 with low hydrogen overvoltage are preferable, and a catalyst layer having a composition in which the Ru content is 20-55 mol%, Ni is 40-34 mol%, and the balance is Pt is supported. An electrode for hydrogen generation is preferred.
本発明の水素発生用電極は、水の電気分解又は食塩などのアルカリ金属塩化物水溶液の
電気分解に使用でき、食塩電解工業を初めてとして広範な電解工業に利用される可能性を
有する。
The electrode for hydrogen generation of the present invention can be used for the electrolysis of water or the electrolysis of an aqueous solution of an alkali metal chloride such as sodium chloride, and has the potential to be used in a wide range of electrolysis industries for the first time.
1:基板(ニッケル)に帰属するピーク
2:合金(白金−ニッケル−ルテニウム合金)に帰属するピーク
3:RuO2に帰属するピーク
4:NiOに帰属するピーク
1: Peak attributed to substrate (nickel) 2: Peak attributed to alloy (platinum-nickel-ruthenium alloy) 3: Peak attributed to RuO 2 4: Peak attributed to NiO
Claims (8)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014241836A JP6515509B2 (en) | 2013-12-26 | 2014-11-28 | ELECTRODE FOR HYDROGEN GENERATION, METHOD FOR PRODUCING THE SAME, AND ELECTROLYTIC METHOD USING THE SAME |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013270496 | 2013-12-26 | ||
JP2013270496 | 2013-12-26 | ||
JP2014241836A JP6515509B2 (en) | 2013-12-26 | 2014-11-28 | ELECTRODE FOR HYDROGEN GENERATION, METHOD FOR PRODUCING THE SAME, AND ELECTROLYTIC METHOD USING THE SAME |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2015143388A true JP2015143388A (en) | 2015-08-06 |
JP6515509B2 JP6515509B2 (en) | 2019-05-22 |
Family
ID=53888612
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2014241836A Active JP6515509B2 (en) | 2013-12-26 | 2014-11-28 | ELECTRODE FOR HYDROGEN GENERATION, METHOD FOR PRODUCING THE SAME, AND ELECTROLYTIC METHOD USING THE SAME |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP6515509B2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101950465B1 (en) * | 2017-08-11 | 2019-05-02 | 주식회사 엘지화학 | Electrode for electrolysis and preparation method thereof |
EP3492631A4 (en) * | 2017-08-11 | 2019-11-20 | LG Chem, Ltd. | Electrolytic electrode and manufacturing method therefor |
JP2021063246A (en) * | 2019-10-10 | 2021-04-22 | 株式会社豊田中央研究所 | Electrode for reductive reaction, method for manufacturing electrode for reductive reaction, and reaction device using electrode for reductive reaction |
CN114717601A (en) * | 2022-05-17 | 2022-07-08 | 临沂大学 | Three-phase interface composite integrated alkaline water electrolysis hydrogen production electrode and preparation method thereof |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4238311A (en) * | 1978-02-20 | 1980-12-09 | Chlorine Engineers Corporation, Ltd. | Cathode for use in electrolysis and method for the production thereof |
JPS58181879A (en) * | 1977-12-09 | 1983-10-24 | オロンジオ・ド・ノラ・イムピアンチ・エレットロキミシ・ソシエタ・ペル・アジオニ | Halogen electrolysis manufacture |
JPS6361391B2 (en) * | 1980-04-22 | 1988-11-29 | ||
JPH0125836B2 (en) * | 1980-10-21 | 1989-05-19 | Orontsuio De Noora Sa | |
JPH0375635B2 (en) * | 1983-05-31 | 1991-12-02 | Dow Chemical Co | |
JPH04231491A (en) * | 1990-05-29 | 1992-08-20 | Dow Chem Co:The | Electric catalyzer cathode and its manufacture |
JPH0713310B2 (en) * | 1984-12-14 | 1995-02-15 | オロンジオ・ド・ノラ・イムピアンチ・エレットロキミシ・ソシエタ・ペル・アジオニ | Cathode used in an electrochemical process, in particular in an electrolytic cell for the electrolysis of alkali metal chlorides, and a process for its production |
JP2005330575A (en) * | 2004-04-23 | 2005-12-02 | Tosoh Corp | Electrode for generating hydrogen, manufacturing method therefor and electrolysis method using it |
-
2014
- 2014-11-28 JP JP2014241836A patent/JP6515509B2/en active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58181879A (en) * | 1977-12-09 | 1983-10-24 | オロンジオ・ド・ノラ・イムピアンチ・エレットロキミシ・ソシエタ・ペル・アジオニ | Halogen electrolysis manufacture |
US4238311A (en) * | 1978-02-20 | 1980-12-09 | Chlorine Engineers Corporation, Ltd. | Cathode for use in electrolysis and method for the production thereof |
JPS6013074B2 (en) * | 1978-02-20 | 1985-04-04 | クロリンエンジニアズ株式会社 | Electrolytic cathode and its manufacturing method |
JPS6361391B2 (en) * | 1980-04-22 | 1988-11-29 | ||
JPH0125836B2 (en) * | 1980-10-21 | 1989-05-19 | Orontsuio De Noora Sa | |
JPH0375635B2 (en) * | 1983-05-31 | 1991-12-02 | Dow Chemical Co | |
JPH0713310B2 (en) * | 1984-12-14 | 1995-02-15 | オロンジオ・ド・ノラ・イムピアンチ・エレットロキミシ・ソシエタ・ペル・アジオニ | Cathode used in an electrochemical process, in particular in an electrolytic cell for the electrolysis of alkali metal chlorides, and a process for its production |
JPH04231491A (en) * | 1990-05-29 | 1992-08-20 | Dow Chem Co:The | Electric catalyzer cathode and its manufacture |
JP2005330575A (en) * | 2004-04-23 | 2005-12-02 | Tosoh Corp | Electrode for generating hydrogen, manufacturing method therefor and electrolysis method using it |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101950465B1 (en) * | 2017-08-11 | 2019-05-02 | 주식회사 엘지화학 | Electrode for electrolysis and preparation method thereof |
EP3492631A4 (en) * | 2017-08-11 | 2019-11-20 | LG Chem, Ltd. | Electrolytic electrode and manufacturing method therefor |
US11396709B2 (en) | 2017-08-11 | 2022-07-26 | Lg Chem, Ltd. | Electrode for electrolysis and preparation method thereof |
JP2021063246A (en) * | 2019-10-10 | 2021-04-22 | 株式会社豊田中央研究所 | Electrode for reductive reaction, method for manufacturing electrode for reductive reaction, and reaction device using electrode for reductive reaction |
JP7347098B2 (en) | 2019-10-10 | 2023-09-20 | 株式会社豊田中央研究所 | Electrode for reduction reaction, method for manufacturing electrode for reduction reaction, and reaction device using electrode for reduction reaction |
CN114717601A (en) * | 2022-05-17 | 2022-07-08 | 临沂大学 | Three-phase interface composite integrated alkaline water electrolysis hydrogen production electrode and preparation method thereof |
CN114717601B (en) * | 2022-05-17 | 2024-01-30 | 临沂大学 | Three-phase interface composite integrated alkaline water electrolysis hydrogen production electrode and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
JP6515509B2 (en) | 2019-05-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2015098058A1 (en) | Electrode for hydrogen generation, process for producing same, and method of electrolysis therewith | |
US7959774B2 (en) | Cathode for hydrogen generation | |
CN102762776B (en) | Activated cathode for hydrogen evolution | |
WO2005035444A2 (en) | Electro-catalysts for the oxidation of ammonia in alkaline media | |
JP4882218B2 (en) | Electrode for hydrogen generation, method for producing the same, and electrolysis method using the same | |
CN1938453B (en) | Electrode for generating hydrogen, manufacturing method therefor and electrolysis method using it | |
TW201231727A (en) | Electrode for electrolysis, electrolytic cell and production method for electrode for electrolysis | |
JP6515509B2 (en) | ELECTRODE FOR HYDROGEN GENERATION, METHOD FOR PRODUCING THE SAME, AND ELECTROLYTIC METHOD USING THE SAME | |
JP6609913B2 (en) | Electrode for hydrogen generation, method for producing the same, and electrolysis method using the same | |
CN113242915B (en) | Electrode for electrolysis | |
JP6753195B2 (en) | Manufacturing method of hydrogen generation electrode and electrolysis method using hydrogen generation electrode | |
JP2022166266A (en) | Method of producing hydrogen generating electrode, and electrolysis method using hydrogen generating electrode | |
JP2006118022A (en) | Electrode for generating hydrogen, precursor of electrode for generating hydrogen, manufacturing method therefor, and electrolysis method using it | |
WO2020110527A1 (en) | Hydrogen generation electrode, method of producing same, and hydrogen production method | |
JP6878917B2 (en) | Electrode for hydrogen generation, its manufacturing method, and electrolysis method using it | |
JP6926782B2 (en) | Hydrogen generation electrode and its manufacturing method and electrolysis method using hydrogen generation electrode | |
JP5271429B2 (en) | Cathode for hydrogen generation | |
TW202407156A (en) | Hydrogen generating electrode and manufacturing method thereof to provide a hydrogen generating electrode that can effectively reduce the cell voltage when the hydrogen generating electrode is assembled into an electrolytic cell and effectively suppress peeling and falling off of the electrode catalyst caused by reverse current when electrolysis is stopped | |
JPWO2012029162A1 (en) | Method for producing electrode for hydrogen generation and electrode for hydrogen generation |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20171019 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20180809 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20180904 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20181101 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20190319 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20190401 |
|
R151 | Written notification of patent or utility model registration |
Ref document number: 6515509 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |