JP3338138B2 - Gas diffusion electrode - Google Patents
Gas diffusion electrodeInfo
- Publication number
- JP3338138B2 JP3338138B2 JP21495693A JP21495693A JP3338138B2 JP 3338138 B2 JP3338138 B2 JP 3338138B2 JP 21495693 A JP21495693 A JP 21495693A JP 21495693 A JP21495693 A JP 21495693A JP 3338138 B2 JP3338138 B2 JP 3338138B2
- Authority
- JP
- Japan
- Prior art keywords
- gas diffusion
- gas
- diffusion electrode
- electrode
- layer
- 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.)
- Expired - Fee Related
Links
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
- Y02E60/50—Fuel cells
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電解、電池、重水電解
再結合触媒等に用いるガス拡散電極に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas diffusion electrode for use in electrolysis, batteries, heavy water electrolytic recombination catalysts, and the like.
【０００２】[0002]
【従来の技術】一般のガス拡散電極は、撥水性カーボン
ブラックとポリ四弗化エチレンよりなるガス拡散層と、
撥水性と親水性の両カーボンブラックとポリ四弗化エチ
レンよりなる白金触媒の担持された反応層とが接合され
たものである。このガス拡散電極を、電解操作中に陽極
及び陰極から発生するガスを電解液中に戻すことにより
電解液からガスとなって減少する物質を無くす為に電解
槽を密閉して行う電解方法の電極に用いた場合、ガスの
供給を電解液に漬からない部分から供給しなければなら
ない為、密閉電解槽にガス供給用の配管が必要となる。
特に上記ガス拡散電極を陰極として用い、Ｏ2 を還元す
る場合、電解液と気相の界面でカーボン、Ｐｔ、Ｏ2 が
存在する為、電流が流れなくともカーボンが酸化されて
しまう。2. Description of the Related Art A general gas diffusion electrode comprises a gas diffusion layer comprising water-repellent carbon black and polytetrafluoroethylene;
Both the water-repellent and hydrophilic carbon blacks and the reaction layer carrying a platinum catalyst made of polytetrafluoroethylene are joined. This gas diffusion electrode is an electrode of an electrolysis method in which the gas generated from the anode and the cathode during the electrolysis operation is returned to the electrolyte, and the electrolytic cell is hermetically sealed in order to eliminate a substance that becomes a gas from the electrolyte and decreases. In the case of using such a gas, the gas must be supplied from a portion not immersed in the electrolytic solution, so that a gas supply pipe is required in the sealed electrolytic cell.
In particular, when using the above gas diffusion electrode as a cathode to reduce O 2 , carbon, Pt, and O 2 are present at the interface between the electrolyte and the gas phase, so that carbon is oxidized even without current flow.
【０００３】[0003]
【発明が解決しようとする課題】そこで本発明は、密閉
電解を有効に行うことができるようにすると共に、ガス
供給用配管を不要にし、特にＯ2 ガスを用いる場合は電
解槽を大気開放型の簡便なものにできるガス拡散電極を
提供しようとするものである。SUMMARY OF THE INVENTION Accordingly, the present invention enables effective closed electrolysis and eliminates the need for a gas supply pipe. In particular, when O 2 gas is used, the electrolytic cell is open to the atmosphere. It is intended to provide a gas diffusion electrode which can be simplified.
【０００４】[0004]
【課題を解決するための手段】上記課題を解決するため
の本発明のガス拡散電極は、内部に空間を有する電導性
物質でできた多孔体の表面が撥水性とされた集電体を骨
格とし、集電体の外面部にガス拡散層と反応層が設けら
れているものである。なおここで用いられる内部に空間
を有する電導性物質でできた多孔体としては、電導物質
の発泡体、網状積層体又はコルゲート板等があげられ
る。According to the present invention, there is provided a gas diffusion electrode comprising a current collector having a porous body made of a conductive material having a space therein and having a water-repellent surface. A gas diffusion layer and a reaction layer are provided on the outer surface of the current collector. The porous body made of a conductive material having a space therein as used herein includes a foam of a conductive material, a net-like laminate, a corrugated plate, and the like.
【０００５】またここで用いられるガス拡散層は、フッ
素樹脂又はフッ素樹脂とフッ素炭素等の撥水性物質の混
合体より成る多孔体が好ましく、反応層としては、少な
くとも触媒及びフッ素樹脂から成る多孔体が好ましい。
さらにこれらガス拡散層及び反応層は電極外面部全面に
設けられた物ばかりでなく、電極が電解液と接する部分
のみに反応層が設けられたものでも良いものである。The gas diffusion layer used here is preferably a porous body composed of a fluororesin or a mixture of a fluororesin and a water-repellent substance such as fluorocarbon, and the reaction layer is preferably a porous body composed of at least a catalyst and a fluororesin. Is preferred.
Further, the gas diffusion layer and the reaction layer may be not only those provided on the entire outer surface of the electrode but also those having a reaction layer only at a portion where the electrode is in contact with the electrolytic solution.
【０００６】[0006]
【作用】上記のように構成された本発明のガス拡散電極
は、電解液に漬からない部分からガスが浸透して集電体
の内部に供給され、ここから電解液に漬かる部分の外面
部に形成されたガス拡散層を経由して反応層に供給さ
れ、電解反応でイオンとなり電解液中に戻される。従っ
て、電解液からガスとなって減少する物質をイオンとし
て戻し、密閉電解を有効に行うことができる。In the gas diffusion electrode of the present invention having the above-described structure, the gas permeates from the portion not immersed in the electrolyte and is supplied to the inside of the current collector, and the outer surface of the portion immersed in the electrolyte therefrom Is supplied to the reaction layer via the gas diffusion layer formed in the above, and is converted into ions by the electrolytic reaction and returned into the electrolytic solution. Therefore, the substance which becomes a gas from the electrolytic solution and decreases can be returned as ions, and the sealed electrolysis can be effectively performed.
【０００７】[0007]
【実施例】本発明のガス拡散電極の一実施例を図１によ
って説明すると、１は撥水化処理された金属多孔体、本
例では穴径50μｍの多孔体にて構成した集電体で、この
集電体１の外面部全面に 0.3μｍのポリ四弗化エチレン
粉末のみよりなる多孔体のガス拡散層２が形成され、そ
の外表面の電解液５に漬かる部分には、電導性触媒粒
子、本例では 0.005μｍのＰｔ粒子と 0.3μｍのポリ四
弗化エチレン粉末とよりなる反応層３が形成されてい
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the gas diffusion electrode of the present invention will be described with reference to FIG. A porous gas diffusion layer 2 made of only 0.3 μm polytetrafluoroethylene powder is formed on the entire outer surface of the current collector 1, and a portion of the outer surface that is immersed in the electrolyte 5 has a conductive catalyst. A reaction layer 3 composed of particles, in this example, 0.005 μm Pt particles and 0.3 μm polytetrafluoroethylene powder is formed.
【０００8 】このように構成された実施例のガス拡散電
極４を、図２に示すように密閉電解槽６の電解液５中で
−負極として、Ｎｉ化合物よりなる＋正極７と組み合わ
せて電池を構成する。充電時には電解液５中のＨ+ がガ
ス拡散電極４上の反応層３で反応してＨ2 ガスとなり、
このＨ2 ガスがガス拡散電極４の内部を伝って上昇し、
密閉電解槽６の上部空間に放散される。この上部空間に
放散、加圧されたＨ2ガスは、放電時にガス拡散電極４
の電解液５に漬からない部分の外表面のガス拡散層２を
浸透して、撥水化処理したＮｉの多孔体の集電体１内に
入り、ここから電解液５に漬かる部分の外表面の反応層
３を透過する際、Ｈ2 →２Ｈ+ ＋２ｅ-の反応が行わ
れ、Ｈ+ が電解液５中に戻される。A battery was prepared by combining the gas diffusion electrode 4 of the embodiment thus constructed in the electrolytic solution 5 of the closed electrolytic cell 6 as a negative electrode and a positive electrode 7 made of a Ni compound as shown in FIG. Constitute. At the time of charging, H + in the electrolyte 5 reacts in the reaction layer 3 on the gas diffusion electrode 4 to become H 2 gas,
This H 2 gas rises along the inside of the gas diffusion electrode 4,
It is dissipated in the upper space of the closed electrolytic cell 6. The H 2 gas diffused and pressurized into the upper space is used as a gas diffusion electrode 4 during discharge.
The gas diffusion layer 2 on the outer surface of the portion not immersed in the electrolyte 5 permeates into the water-repellent treated porous Ni current collector 1, and from outside the portion immersed in the electrolyte 5 When passing through the reaction layer 3 on the surface, a reaction of H 2 → 2H + + 2e − is performed, and H + is returned to the electrolyte 5.
【０００９】図３の他の実施例は、密閉電解槽６の電解
液５中でガス拡散電極４を＋正極として、Ｚｎよりなる
−負極８と組み合わせて電池を構成した場合である。充
電時には−極８上ではＺｎの析出が起こり、ガス拡散電
極４上の反応層３では電解液５中のＯＨ- 反応してＯ2
ガスとなり、このＯ2 ガスはガス拡散電極４の内部を伝
って上昇し、密閉電解槽６の上部空間に放散される。こ
の上部空間に放散、加圧されたＯ2 ガスは、ガス拡散電
極４の電解液５に漬からない外表面のガス拡散層２に浸
透し、撥水化処理したＮｉの多孔体１内に入り、ここか
ら電解液５に漬かる部分の外表面の反応層を透過する
際、Ｈ2 Ｏ＋ 1/2Ｏ2 ＋２ｅ- →２ＯＨ-の反応が行わ
れ、ＯＨ- が電解液５中に戻される。FIG. 3 shows another embodiment in which a battery is formed by combining the gas diffusion electrode 4 in the electrolyte 5 of the closed electrolytic cell 6 with the positive electrode and the negative electrode 8 made of Zn. At the time of charging, Zn precipitates on the negative electrode 8, and in the reaction layer 3 on the gas diffusion electrode 4, OH − in the electrolytic solution 5 reacts and O 2
This O 2 gas rises along the inside of the gas diffusion electrode 4 and is diffused into the upper space of the closed electrolytic cell 6. The O 2 gas diffused and pressurized into the upper space penetrates into the gas diffusion layer 2 on the outer surface which is not immersed in the electrolyte 5 of the gas diffusion electrode 4, and enters the water-repellent Ni porous body 1. When entering and permeating through the reaction layer on the outer surface of the part immersed in the electrolyte 5, a reaction of H 2 O + 1 / 2O 2 + 2e − → 2OH − is performed, and OH − is returned into the electrolyte 5.
【００１０】なお上記実施例で用いた本発明のガス拡散
電極は、集電体の電解液に漬かる部分は、ガス拡散層を
設けたのち、その外面に反応層を設けたものであるが、
ガス拡散層を設けず集電体上に直接反応層を設けたもの
でも良いものである。In the gas diffusion electrode of the present invention used in the above embodiment, a portion of the current collector to be immersed in the electrolytic solution is provided with a gas diffusion layer and a reaction layer on its outer surface.
A structure in which a reaction layer is provided directly on a current collector without providing a gas diffusion layer may be used.
【００１１】さらに上記実施例は、Ｈ2 ガスやＯ2 ガス
を用いる電池の場合であるが、本発明のガス拡散電極
は、電極操作中に陽極よりＯ2 ガス、陰極よりＨ2 ガス
を発生する電解、例えば低温核融合の実験で重水を電解
する操作や陽極からＣｌ2 ガス、陰極からＨ2 ガスを発
生する塩化物溶液の電解にも密閉電解槽において利用で
き、さらに前記重水電解の再結合触媒としても利用する
ことができる。また局部電池反応で液中のメタノール、
ギ酸、ホルムアルデヒド、ヒドラジン等の酸化分解にも
使用できる。In the above embodiment, a battery using H 2 gas or O 2 gas is used. The gas diffusion electrode of the present invention generates O 2 gas from the anode and H 2 gas from the cathode during operation of the electrode. Electrolysis, such as the operation of electrolyzing heavy water in cold fusion experiments and the electrolysis of chloride solutions that generate Cl 2 gas from the anode and H 2 gas from the cathode, can be used in a closed electrolytic cell. It can also be used as a binding catalyst. In addition, methanol in the liquid by local battery reaction,
It can also be used for oxidative decomposition of formic acid, formaldehyde, hydrazine and the like.
【００１２】[0012]
【発明の効果】以上の通り本発明のガス拡散電極は、密
閉電解槽の電極に用いると、電解反応により電解液より
ガスが密閉電解槽の上部空間に放出されるが、このガス
がガス拡散電極に供給されて反応が行われ、元の物質に
して電解液中に戻すことができるので、電解液からガス
となって減少する物質が無くなり、密閉電解を有効に行
うことができる。また本発明のガス拡散電極は、自動的
にガスが供給されるので、ガス供給用配管は不要であ
り、特に本発明のガス拡散電極に供給されるガスがＯ2
ガスの場合は電解槽を大気開放型の簡便なものにでき
る。またガス供給用配管が不要となったので、電極全体
が電解液で冷却されて、発熱が抑えられる。As described above, when the gas diffusion electrode of the present invention is used as an electrode in a closed electrolytic cell, gas is released from the electrolytic solution into the upper space of the closed electrolytic cell by an electrolytic reaction. Since the reaction is carried out by being supplied to the electrode, the substance can be converted into the original substance and returned into the electrolytic solution, so that there is no substance that becomes a gas from the electrolytic solution and decreases, and the sealed electrolysis can be effectively performed. Further, since the gas is automatically supplied to the gas diffusion electrode of the present invention, a gas supply pipe is unnecessary, and particularly, the gas supplied to the gas diffusion electrode of the present invention is O 2.
In the case of gas, the electrolytic cell can be made simple and open to the atmosphere. In addition, since the gas supply pipe becomes unnecessary, the entire electrode is cooled by the electrolytic solution, thereby suppressing heat generation.
【００１１】[0011]
【図１】本発明のガス拡散電極を示す図である。FIG. 1 is a view showing a gas diffusion electrode of the present invention.
【図２】図１のガス拡散電極を負極とし、Ｎｉ化合物を
正極とした密閉電解槽による電池の例を示す図である。2 is a diagram showing an example of a battery using a sealed electrolytic cell in which the gas diffusion electrode of FIG. 1 is used as a negative electrode and a Ni compound is used as a positive electrode.
【図３】図１のガス拡散電極を正極とし、Ｚｎを負極と
した密閉電解槽による電池の例を示す図である。3 is a diagram showing an example of a battery using a sealed electrolytic cell in which the gas diffusion electrode of FIG. 1 is used as a positive electrode and Zn is used as a negative electrode.
１ 撥水化処理した金属多孔体の集電体 ２ ガス拡散電極 ３ 反応層 ４ ガス拡散電極 DESCRIPTION OF SYMBOLS 1 Current collector of metal porous body which carried out water repellency treatment 2 Gas diffusion electrode 3 Reaction layer 4 Gas diffusion electrode
Claims (5)
多孔体の表面が撥水性とされた集電体を骨格とし、集電
体の外面部にガス拡散層と反応層が設けられていること
を特徴とするガス拡散電極。1. A current collector whose surface is made of a water-repellent porous body made of a conductive substance having a space therein, and a gas diffusion layer and a reaction layer are provided on an outer surface of the current collector. A gas diffusion electrode.
きた多孔体が、電導性物質の発泡体、網状積層体又はコ
ルゲート板である請求項１記載のガス拡散電極。2. The gas diffusion electrode according to claim 1, wherein the porous body made of a conductive material having a space therein is a foam, a net-like laminate, or a corrugated plate of the conductive material.
樹脂と撥水性物質の混合物の多孔体である、請求項１又
は請求項２記載のガス拡散電極。Wherein a porous body of the gas diffusion layer is a mixture of fluorine resin or fluorine resin and the water repellent material, according to claim 1 or claim 2 gas diffusion electrode according.
樹脂から成る多孔体である、請求項１、請求項２又は請
求項３記載のガス拡散電極。4. The gas diffusion electrode according to claim 1, wherein said reaction layer is a porous body comprising at least a catalyst and a fluororesin.
分のみに設けられていることを特徴とする請求項１、請
求項２、請求項３又は請求項４記載のガス拡散電極。5. The gas diffusion electrode according to claim 1, wherein the reaction layer is provided only on a portion of the electrode that contacts the electrolyte.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21495693A JP3338138B2 (en) | 1993-08-06 | 1993-08-06 | Gas diffusion electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21495693A JP3338138B2 (en) | 1993-08-06 | 1993-08-06 | Gas diffusion electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0754181A JPH0754181A (en) | 1995-02-28 |
| JP3338138B2 true JP3338138B2 (en) | 2002-10-28 |
Family
ID=16664351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21495693A Expired - Fee Related JP3338138B2 (en) | 1993-08-06 | 1993-08-06 | Gas diffusion electrode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3338138B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6088048B2 (en) | 2012-06-12 | 2017-03-01 | モナシュ ユニバーシティ | Breathable electrode structure and method and system for water splitting |
| BR112016002269A2 (en) | 2013-07-31 | 2017-08-01 | Aquahydrex Pty Ltd | method and electrochemical cell to manage electrochemical reactions |
| KR20210122260A (en) | 2019-02-01 | 2021-10-08 | 아쿠아하이드렉스, 인크. | Electrochemical systems with limited electrolytes |
-
1993
- 1993-08-06 JP JP21495693A patent/JP3338138B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0754181A (en) | 1995-02-28 |
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