JPH0238672B2 - - Google Patents
Info
- Publication number
- JPH0238672B2 JPH0238672B2 JP61078024A JP7802486A JPH0238672B2 JP H0238672 B2 JPH0238672 B2 JP H0238672B2 JP 61078024 A JP61078024 A JP 61078024A JP 7802486 A JP7802486 A JP 7802486A JP H0238672 B2 JPH0238672 B2 JP H0238672B2
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- electrode
- coating
- mol
- indium
- 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 - Lifetime
Links
- 238000000576 coating method Methods 0.000 claims description 33
- 239000011248 coating agent Substances 0.000 claims description 31
- 238000005868 electrolysis reaction Methods 0.000 claims description 20
- 230000000694 effects Effects 0.000 claims description 14
- 239000000758 substrate Substances 0.000 claims description 14
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 12
- 239000002131 composite material Substances 0.000 claims description 11
- 229910052738 indium Inorganic materials 0.000 claims description 10
- 150000003839 salts Chemical class 0.000 claims description 10
- 229910052718 tin Inorganic materials 0.000 claims description 10
- HTXDPTMKBJXEOW-UHFFFAOYSA-N dioxoiridium Chemical compound O=[Ir]=O HTXDPTMKBJXEOW-UHFFFAOYSA-N 0.000 claims description 8
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 8
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 8
- 229910001887 tin oxide Inorganic materials 0.000 claims description 8
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 7
- 229910003437 indium oxide Inorganic materials 0.000 claims description 7
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 claims description 7
- 229910000457 iridium oxide Inorganic materials 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- 229910052741 iridium Inorganic materials 0.000 claims description 4
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 3
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical group [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 3
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims 2
- 239000010941 cobalt Substances 0.000 claims 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical group [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims 2
- 239000000460 chlorine Substances 0.000 description 18
- 229910052801 chlorine Inorganic materials 0.000 description 18
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 17
- 235000002639 sodium chloride Nutrition 0.000 description 10
- 239000010936 titanium Substances 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 239000013535 sea water Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 239000010948 rhodium Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 5
- 229910001507 metal halide Inorganic materials 0.000 description 5
- 150000005309 metal halides Chemical class 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- -1 hypochlorite ions Chemical class 0.000 description 4
- 229910044991 metal oxide Inorganic materials 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000004706 metal oxides Chemical class 0.000 description 3
- 239000010955 niobium Substances 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 229910020599 Co 3 O 4 Inorganic materials 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 239000008199 coating composition Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 229910052707 ruthenium Inorganic materials 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 229910021627 Tin(IV) chloride Inorganic materials 0.000 description 1
- 229910010977 Ti—Pd Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910001508 alkali metal halide Inorganic materials 0.000 description 1
- 150000008045 alkali metal halides Chemical class 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001804 chlorine Chemical class 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- PSCMQHVBLHHWTO-UHFFFAOYSA-K indium(iii) chloride Chemical compound Cl[In](Cl)Cl PSCMQHVBLHHWTO-UHFFFAOYSA-K 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 230000009182 swimming Effects 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- HPGGPRDJHPYFRM-UHFFFAOYSA-J tin(iv) chloride Chemical compound Cl[Sn](Cl)(Cl)Cl HPGGPRDJHPYFRM-UHFFFAOYSA-J 0.000 description 1
- DANYXEHCMQHDNX-UHFFFAOYSA-K trichloroiridium Chemical compound Cl[Ir](Cl)Cl DANYXEHCMQHDNX-UHFFFAOYSA-K 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Description
〔産業上の利用分野〕
この発明は、金属ハロゲン化物水溶液等の電解
に用いる電解用電極に関し、特に希薄食塩水や海
水等の低温、低濃度アルカリ金属ハロゲン化物の
電解に好適な電解用電極及びその製造方法に関す
る。
〔従来の技術と問題点〕
これまで、海水等の希薄塩水を電解して陽極に
塩素を発生させる電解用装置は、例えば次亜塩素
酸塩の製造や海中構造物への生物の付着防止、プ
ールや上下水道の水処理などに使用されてきてい
る。このような電解では通常、無隔膜電解装置に
より、陽極に塩素を発生させ、この塩素と水酸イ
オンとの反応により次亜塩素酸イオンが生成し、
前記したような用途においては、該生成物を殺
菌、漂白などに利用するものであるが、これらの
電解装置は、長期間の連続運転を効率良く、しか
も確実に行う必要があるため、用いられる陽極は
所期の電極特性を維持しつつ高度の耐久性が要求
される。
すなわち、海水等の電解においては、比較的高
温度で高濃度の食塩水による塩素アルカリ電解の
場合と異なり、電解液の濃度や温度等電解条件が
一定でなく、しかも海水の温度は自然条件により
10℃以下に低下する場合があり、海水中の食塩濃
度は通常３％前後と低く、溶存する不純物も多い
ので、用いる電極においてもこれらの条件下で十
分高い塩素発生効率及び耐久性などの諸要求を満
たさねばならない。
従来、海水等の電解用電極として、白金又は白
金族金属の合金を耐食性基体上にメツキした金属
電極が知られているが、これらは比較的消耗速度
が大きく、そのため被覆の厚さを大きくする必要
があり、非常に高価格となる。又電気化学的特性
上も問題があり、電解における塩素発生電位が高
く、酸素発生電位との差が殆ど無い。従つて、電
流効率が良くなく操業時の電解電圧が高くなる等
の欠点を有していた。
又、食塩等の金属ハロゲン化物の水溶液電解用
電極として、ルテニウム等の白金族金属の酸化物
を主体とする電極被覆をチタン等の耐食性基体上
に設けた電極が種々知られている（例えば特公昭
48−3954号、特公昭50−11330号）が、これら従
来の電極は酸素発生量が比較的多い欠点があり、
海水等の低温、低濃度での使用に適するものとは
言えなかつた。
又、特開昭51−63374号には、白金族金属酸化
物にインジウム（In）酸化物を組成させた被覆層
を有する電極が記載されている。この電極は塩素
過電圧が低く、耐久性を有する安価な陽極を目的
としたものであるが、白金族金属成分としてロジ
ウム（Rh）を用い、実質的にRh2O3−In2O3又は
これに少量スズ酸化物を加えた被覆電極を提示し
たものである。即ち、被覆酸化物の主体がR2O3
型（Ｒは金属を示す）であり、そのため、基体の
Tiとの結合性及び被覆の安定性がルチル型
（RO2型）被覆に比べて劣り、電極としての耐久
性が不十分であり、且つ塩素過電圧が比較的高い
問題があり、低温、希薄塩水の電解用に適するも
のとは言えない。
〔発明の目的〕
本発明は、高温、高濃度の金属ハロゲン化物水
溶液の電解のみならず、低温、低濃度の金属ハロ
ゲン化物水溶液電解においても、塩素電圧が低
く、高い電流効率と優れた耐久性を有する電解用
電極及びその製造方法を提供することを目的とす
るものである。
〔問題を解決するための手段及び作用〕
本発明の目的は、下記の本発明によつて達成さ
れる。
即ち、第(1)の発明は、
導電性基体上に、電極触媒活性を有する被覆を
設けた電解用電極において、該被覆が20〜70モル
％のイリジウム酸化物と、合計して80〜30モル％
のインジウム酸化物及びスズ酸化物（但し、イン
ジウムとスズの原子比が90：10〜10：90である）
とからなり、実質的にルチル型複合酸化物である
ことを特徴とする電解用電極である。
第２の発明は、
導電性基体上に、イリジウム、インジウム、及
びスズの熱分解可能な塩を含む溶液を塗布し、酸
化性雰囲気中で加熱して、該基体上に20〜70モル
％のイリジウム酸化物と、合計して80〜30モル％
のインジウム酸化物及びスズ酸化物（但し、イン
ジウムとスズの原子比が90：10〜10：90である）
とからなり、実質的にルチル型複合酸化物である
電極触媒活性を有する被覆を形成することを特徴
とする電解用電極の製造方法である。
又、本発明において、上記電極触媒活性を有す
る被覆中にインジウム酸化物及びスズ酸化物の一
部を置換して10モル％までのコバルト酸化物を含
有させることが出来る。
以下、本発明をより詳細に説明する。
本発明における導電性基体は、Ti、Ta（タン
タル）、Nb（ニオブ）、Zr（ジルコニウム）等の耐
食性のある導電性金属又はこれらの基合金が用い
られ、従来から用いられている金属Ti、又はTi
−Ta−Nb、Ti−Pd等のTi基合金が好適である。
その形状は板、有孔板、棒状体、網状体等所望の
ものとすることが出来る。
該導電性基体は、適宜、表面清浄化処理等を行
い、本発明の電極触媒活性を有する被覆が設けら
れる。該被覆は、20〜70モル％のIr酸化物と、80
〜30モル％のIn酸化物及びSn酸化物とから基本
的になる複合酸化物であり、Co酸化物を10モル
％まで含有出来るものであつて、該複合酸化物は
実質的にルチル型（RO2型）結晶構造を主体とす
るものである。又、該被覆は金属酸化物の混合
体、固溶体又は両者の混合体等のいずれでも良
い。
Co酸化物を該被覆中に含有する場合、後記す
るように少量のCo酸化物は主体となるルチル型
複合酸化物中に均一に金属酸化物状態で混合又は
固溶し、被覆のルチル型基本構造は変わらない。
本発明で、電極被覆の構造主体をルチル型
（RO2型）としたのは、被覆中にIn酸化物を組成
させる場合、従来の前記特開昭51−63374号にお
けるRh酸化物（Rh2O3）とIn2O3を組み合わせた
R2O3型では、基体との結合性及び被覆の耐消耗
性が不十分であることが分かり、Ir酸化物
（IrO2）及びSn酸化物（SnO2）と組み合わせて
RO2型にすれば、これらの欠点が解消され優れた
電極が得られることを見出したことによる。そし
て、Ir−In−Sn−（Co）の組合せにより、それら
の複合酸化物は全体として容易にルチル型構造と
して被覆することが出来る。
基体に該複合酸化物を被覆する方法としては、
前記特公昭48−3954号に記載の如き種々の手段が
適用できるが、とりわけ、各被覆成分金属の熱分
解可能な無機又は有機の塩を含む溶液を基体上に
塗布し、酸化性雰囲気中で加熱する、いわゆる熱
分解酸化法が好適である。加熱温度は、通常空気
中で300〜650℃が適当である。
本発明における電極被覆を構成する個々の成分
の作用及び組成範囲について、以下に説明する。
(1) Ir酸化物
IrO2は、主に塩素発生用電極触媒として優れ
た機能を有し、特にRuやRhの酸化物に比べて
耐久性を向上させる。そのため、本発明におい
ては被覆中にIrO2の形で20〜70モル％含有する
ことが好ましい。20モル％未満では塩素過電圧
が上昇し、耐久性が低下する傾向があり、又、
70モル％を越えると耐久性が悪くなると共に酸
素発生量が多くなつて電流効率が低下する。
(2) In酸化物及びSn酸化物
両者とも助触媒的機能を有し、塩素過電圧を
低く維持する作用がある。この効果はInがより
顕著であるが、InのみではIn2O3となり耐久性
を悪化させる。Sn酸化物は、同様塩素過電圧
を低くする働きがあり、更にIn酸化物と共に共
存させてInをInO2のルチル型にし、耐食性を
向上させる作用を有する。
そのため、両者はルチル型構造で被覆中に合
計して80〜30モル％含有させることが望まし
い。又、InとSnの相互の組成割合は原子比で
90：10〜10：90の範囲で十分上記効果を達成出
来る。
(3) Co酸化物
Co酸化物は、塩素過電圧を低くしたまま酸
素過電圧を高くする作用があり、電極の塩素発
生電流効率を更に向上させる効果がある。
そのため、In酸化物とSn酸化物をCo酸化物
で総量で10モル％まで置換して電極被覆中に組
成させることが出来る。
しかし、10モル％を越えるとルチル型酸化物
被覆の基本構造を変えないで存在させることが
困難となり、CoO、Co3O4やCo2O3等の他の結
晶相が出現し、電極の耐久性が悪化する。
〔実施例〕
以下本発明の実施例を記載するが、これらの実
施例は本発明を限定するものではない。
実施例 １
予めブチルアルコールと塩化第二スズからアル
コキシスズを作製し、それをアミルアルコールで
希釈し、更に塩化インジウムを溶解し、更に12時
間加熱還流して所定濃度の第１液を作製した。
第２液として、塩化イリジウムと、必要に応じ
て塩化コバルトをアミルアルコールに溶解し、12
時間加熱還流して所定濃度の第２液を作製した。
これら第１液第２液を所定割合に混合して各種
の塗布液を作製した。
この塗布液を、予め脱脂し、80℃、25％
H2SO4水溶液中で４時間エツチングした純チタ
ン板基体（大きさ100×100mm、厚さ１mm）にブラ
シで塗布し、10分間室温にて乾燥後、150℃にて
15分間加熱乾燥した。更にこれを空気を循環した
530℃のマツフル炉中で10分間加熱した。
塗布−加熱の工程を８回繰り返して、第１表に
示す各組成（金属のみを示す）の複合酸化物被覆
を有する試料電極を作製した。
これらの試料について、Ｘ線回折法による被覆
組成物の存在状態を測定し、10℃、30ｇ／
NaCl水溶液中における塩素発生電位及び電流効
率、並びに５℃、30ｇ／NaCl水溶液中におけ
る電極寿命試験をおこなつた。比較として従来の
Ru−Ti系、Ru−Sn系、Rh−In系及びPtメツキ
Ti電極を作製し、同様に試験した。
それらの試験を合わせて第１表に示す。
[Industrial Application Field] The present invention relates to an electrolytic electrode used for electrolyzing metal halide aqueous solutions, etc., and particularly to an electrolytic electrode suitable for electrolyzing low-temperature, low-concentration alkali metal halides such as dilute saline solution and seawater. It relates to its manufacturing method. [Conventional technology and problems] Until now, electrolysis equipment that electrolyzes dilute salt water such as seawater to generate chlorine at the anode has been used, for example, to produce hypochlorite, to prevent the attachment of living things to underwater structures, It has been used for water treatment in swimming pools and water and sewage systems. In such electrolysis, chlorine is usually generated at the anode using a non-diaphragm electrolyzer, and hypochlorite ions are generated by the reaction between this chlorine and hydroxide ions.
In the above-mentioned applications, the product is used for sterilization, bleaching, etc., and these electrolyzers are used because they need to operate continuously for long periods of time efficiently and reliably. The anode is required to have a high degree of durability while maintaining desired electrode characteristics. In other words, in electrolysis of seawater, etc., unlike chlor-alkali electrolysis using relatively high-temperature, high-concentration salt water, the electrolytic conditions such as the concentration and temperature of the electrolyte are not constant, and the temperature of seawater varies depending on natural conditions.
The salt concentration in seawater is usually low, around 3%, and there are many dissolved impurities, so the electrodes used must have sufficiently high chlorine generation efficiency and durability under these conditions. must meet the requirements. Conventionally, metal electrodes made of platinum or platinum group metal alloy plated on a corrosion-resistant substrate have been known as electrodes for electrolysis of seawater, etc., but these wear out at a relatively high rate, so the thickness of the coating must be increased. necessary, and the price is very high. There are also problems in terms of electrochemical properties; the chlorine generation potential during electrolysis is high, and there is almost no difference from the oxygen generation potential. Therefore, it has disadvantages such as poor current efficiency and high electrolysis voltage during operation. Furthermore, as electrodes for aqueous electrolysis of metal halides such as common salt, various electrodes are known in which an electrode coating mainly composed of an oxide of a platinum group metal such as ruthenium is provided on a corrosion-resistant substrate such as titanium (for example, Kimiaki
48-3954, Japanese Patent Publication No. 50-11330), but these conventional electrodes have the disadvantage of generating a relatively large amount of oxygen.
It could not be said that it was suitable for use in low-temperature, low-concentration environments such as seawater. Further, JP-A-51-63374 describes an electrode having a coating layer composed of a platinum group metal oxide and an indium (In) oxide. This electrode was intended to be an inexpensive anode with low chlorine overvoltage and durability, but it uses rhodium (Rh) as the platinum group metal component and is substantially Rh 2 O 3 -In 2 O 3 or this. This paper presents a coated electrode to which a small amount of tin oxide is added. That is, the coating oxide is mainly R 2 O 3
type (R indicates metal), so that the substrate
Bondability with Ti and coating stability are inferior to rutile type (RO 2 type) coatings, and durability as an electrode is insufficient, and chlorine overvoltage is relatively high. It cannot be said that it is suitable for electrolysis. [Object of the Invention] The present invention provides low chlorine voltage, high current efficiency, and excellent durability not only in the electrolysis of high-temperature, high-concentration metal halide aqueous solutions, but also in low-temperature, low-concentration metal halide aqueous solution electrolysis. An object of the present invention is to provide an electrode for electrolysis having the following characteristics and a method for manufacturing the same. [Means and effects for solving the problem] The objects of the present invention are achieved by the present invention described below. That is, the invention (1) provides an electrolytic electrode in which a coating having electrocatalytic activity is provided on a conductive substrate, wherein the coating contains 20 to 70 mol% of iridium oxide and a total of 80 to 30 mol% of iridium oxide. mole%
indium oxide and tin oxide (however, the atomic ratio of indium and tin is 90:10 to 10:90)
This is an electrode for electrolysis, which is made of a substantially rutile-type composite oxide. The second invention is to apply a solution containing thermally decomposable salts of iridium, indium, and tin onto a conductive substrate, heat it in an oxidizing atmosphere, and apply a solution containing 20 to 70 mol% of iridium oxide and a total of 80 to 30 mol%
indium oxide and tin oxide (however, the atomic ratio of indium and tin is 90:10 to 10:90)
A method for producing an electrolytic electrode, comprising forming a coating having electrocatalytic activity that is substantially a rutile-type composite oxide. Further, in the present invention, up to 10 mol % of cobalt oxide can be contained in the electrocatalytically active coating by partially replacing indium oxide and tin oxide. The present invention will be explained in more detail below. The conductive substrate in the present invention is a corrosion-resistant conductive metal such as Ti, Ta (tantalum), Nb (niobium), Zr (zirconium), or a base alloy thereof, and the conventionally used metal Ti, Or Ti
-Ti-based alloys such as Ta-Nb and Ti-Pd are preferred.
Its shape can be any desired, such as a plate, a perforated plate, a rod-like body, or a net-like body. The conductive substrate is suitably subjected to a surface cleaning treatment, etc., and is provided with a coating having electrocatalytic activity of the present invention. The coating contains 20-70 mol% Ir oxide and 80%
It is a composite oxide that basically consists of ~30 mol% of In oxide and Sn oxide, and can contain up to 10 mol% of Co oxide, and the composite oxide is substantially of rutile type ( RO type 2 ) mainly has a crystal structure. Further, the coating may be a mixture of metal oxides, a solid solution, or a mixture of both metal oxides. When Co oxide is contained in the coating, as described later, a small amount of Co oxide is uniformly mixed or dissolved in the metal oxide state in the main rutile type composite oxide, and the rutile type base of the coating The structure remains unchanged. In the present invention, the main structure of the electrode coating is rutile type (RO 2 type).When In oxide is included in the coating, Rh oxide (Rh 2 O 3 ) and In 2 O 3 combined
The R 2 O 3 type was found to have insufficient bonding properties with the substrate and wear resistance of the coating, so it was
This is due to the discovery that these drawbacks can be overcome and an excellent electrode can be obtained by using the RO 2 type. By combining Ir-In-Sn-(Co), these composite oxides can be easily coated as a rutile structure as a whole. The method of coating the composite oxide on the substrate is as follows:
Various methods such as those described in the above-mentioned Japanese Patent Publication No. 48-3954 can be applied, but in particular, a solution containing a thermally decomposable inorganic or organic salt of each coating component metal is applied onto the substrate, and the solution is applied in an oxidizing atmosphere. A so-called pyrolytic oxidation method involving heating is preferred. The appropriate heating temperature is usually 300 to 650°C in air. The effects and composition ranges of the individual components constituting the electrode coating in the present invention will be explained below. (1) Ir oxide IrO 2 has an excellent function mainly as an electrode catalyst for chlorine generation, and particularly improves durability compared to Ru and Rh oxides. Therefore, in the present invention, it is preferable that the coating contains 20 to 70 mol% of IrO2 in the form of IrO2 . If it is less than 20 mol%, chlorine overvoltage tends to increase and durability tends to decrease;
When it exceeds 70 mol%, durability deteriorates and the amount of oxygen generated increases, resulting in a decrease in current efficiency. (2) In oxide and Sn oxide Both have a promoter function and have the effect of keeping the chlorine overvoltage low. This effect is more pronounced with In, but with In alone, it becomes In 2 O 3 and deteriorates durability. Sn oxide similarly has the function of lowering the chlorine overvoltage, and further has the function of making In the rutile type of InO 2 by coexisting with In oxide and improving corrosion resistance. Therefore, it is desirable that both have a rutile structure and be contained in a total of 80 to 30 mol% in the coating. Also, the mutual composition ratio of In and Sn is atomic ratio
The above effects can be sufficiently achieved within the range of 90:10 to 10:90. (3) Co oxide Co oxide has the effect of increasing the oxygen overvoltage while keeping the chlorine overvoltage low, and has the effect of further improving the chlorine generation current efficiency of the electrode. Therefore, it is possible to replace In oxide and Sn oxide with Co oxide in a total amount of up to 10 mol % in the electrode coating. However, if it exceeds 10 mol%, it becomes difficult to maintain the rutile-type oxide coating without changing its basic structure, and other crystal phases such as CoO, Co 3 O 4 and Co 2 O 3 appear, causing the electrode to deteriorate. Durability deteriorates. [Examples] Examples of the present invention will be described below, but these Examples do not limit the present invention. Example 1 Tin alkoxy was prepared in advance from butyl alcohol and stannic chloride, diluted with amyl alcohol, further dissolved in indium chloride, and further heated under reflux for 12 hours to prepare a first liquid with a predetermined concentration. As the second liquid, iridium chloride and, if necessary, cobalt chloride are dissolved in amyl alcohol, and 12
A second liquid having a predetermined concentration was prepared by heating under reflux for a period of time. Various coating solutions were prepared by mixing these first and second solutions at predetermined ratios. This coating solution was degreased in advance and heated to 80°C at 25%
It was applied with a brush to a pure titanium plate substrate (size 100 x 100 mm, thickness 1 mm) that had been etched in an aqueous H 2 SO 4 solution for 4 hours, dried at room temperature for 10 minutes, and then heated at 150°C.
It was heated and dried for 15 minutes. Furthermore, this was used to circulate the air.
It was heated for 10 minutes in a Matsufuru furnace at 530°C. The coating-heating process was repeated eight times to produce sample electrodes having composite oxide coatings having the compositions shown in Table 1 (only metals are shown). For these samples, the presence state of the coating composition was measured by X-ray diffraction method, and the
The chlorine generation potential and current efficiency in a NaCl aqueous solution, and the electrode life test in a 30 g/NaCl aqueous solution at 5°C were conducted. Conventional as a comparison
Ru-Ti system, Ru-Sn system, Rh-In system and Pt plating
A Ti electrode was prepared and tested in the same manner. The tests are shown in Table 1.
【表】
第１表の結果から、本発明による電極は従来の
電極（比較４〜７）に比較して塩素発生電位が低
く、低温低濃度の塩水電解においても電流効率及
び電極の耐久性が格段に優れていることが分か
る。
又、本発明の電極被覆の組成範囲を越え、Ir酸
化物が20モル％未満では（比較１）、塩素発生電
位が高くなり、且つ寿命が短くなる。70モル％を
越えると（比較２）、電流効率が低くなると共に、
寿命も短くなることが分かる。更に、Co酸化物
が10モル％を越えると（比較３）、Co3O4相が出
現し、耐食性が悪化して寿命が短くなる。
実施例 ２
実施例１と同様の操作により、InとSnの被覆
組成比を変えて各種の試料電極を作製し、実施例
１と同じ評価試験を行つた。
その結果を第２表に示す。[Table] From the results in Table 1, the electrode according to the present invention has a lower chlorine generation potential than conventional electrodes (Comparisons 4 to 7), and has improved current efficiency and electrode durability even in low-temperature, low-concentration salt water electrolysis. It turns out that it's significantly better. Moreover, if the composition range of the electrode coating of the present invention is exceeded and the Ir oxide content is less than 20 mol % (Comparison 1), the chlorine generation potential becomes high and the life is shortened. When it exceeds 70 mol% (comparison 2), the current efficiency decreases and
It can be seen that the lifespan is also shortened. Furthermore, when the Co oxide content exceeds 10 mol % (Comparison 3), a Co 3 O 4 phase appears, which deteriorates corrosion resistance and shortens life. Example 2 Various sample electrodes were prepared by changing the coating composition ratio of In and Sn by the same operation as in Example 1, and the same evaluation tests as in Example 1 were conducted. The results are shown in Table 2.
【表】【table】
本発明は、導電性基体上に、Ir−In−Sn−
（Co）系の特定組成のルチル型複合酸化物被覆を
設けたので、塩素過電圧が低く、酸素過電圧が高
く、且つ低温、低濃度の金属ハロゲン化物電解に
おいても、耐久性に富む電解用電極が得られる。
そのため、特に本発明の電極は、低濃度塩水の電
解による次亜塩素酸塩の製造や、海水の電解処理
用の電極として、極めて高い電流効率で且つ長期
間安定して用いることが出来る。
The present invention provides Ir-In-Sn- on a conductive substrate.
(Co)-based rutile-type composite oxide coating with a specific composition provides an electrolytic electrode with low chlorine overvoltage, high oxygen overvoltage, and high durability even in low-temperature, low-concentration metal halide electrolysis. can get.
Therefore, in particular, the electrode of the present invention can be stably used with extremely high current efficiency and for a long period of time as an electrode for the production of hypochlorite by electrolysis of low concentration salt water or for the electrolytic treatment of seawater.
Claims (1)
を設けた電解用電極において、該被覆が20〜70モ
ル％のイリジウム酸化物と、合計して80〜30モル
％のインジウム酸化物及びスズ酸化物（但し、イ
ンジウムとスズの原子比が90：10〜10：90であ
る）とからなり、実質的にルチル型複合酸化物で
あることを特徴とする電解用電極。 ２ インジウム酸化物及びスズ酸化物の総量で10
モル％までをコバルト酸化物で置換した特許請求
の範囲第１項に記載の電解用電極。 ３ 導電性基体上に、イリジウム、インジウム、
及びスズの熱分解可能な塩を含む溶液を塗布し、
酸化性雰囲気中で加熱して該基体上に20〜70モル
％のイリジウム酸化物と、合計して80〜30モル％
のインジウム酸化物及びスズ酸化物（但し、イン
ジウムとスズの原子比が90：10〜10：90である）
とからなり、実質的にルチル型複合酸化物である
電極触媒活性を有する被覆を形成することを特徴
とする電解用電極の製造方法。 ４ イリジウム、インジウム、及びスズの熱分解
可能な塩を含む溶液に、更にコバルトの熱分解可
能な塩を加え、インジウム酸化物及びスズ酸化物
の総量で10モル％までをコバルト酸化物で置換し
た電極触媒活性を有する被覆を形成する特許請求
の範囲第３項に記載の電解用電極の製造方法。[Scope of Claims] 1. An electrolytic electrode in which a coating having electrocatalytic activity is provided on a conductive substrate, wherein the coating contains 20 to 70 mol% of iridium oxide and a total of 80 to 30 mol% of iridium oxide. An electrode for electrolysis comprising indium oxide and tin oxide (provided that the atomic ratio of indium and tin is 90:10 to 10:90) and is substantially a rutile type composite oxide. 2 The total amount of indium oxide and tin oxide is 10
The electrode for electrolysis according to claim 1, wherein up to mol% of cobalt is substituted with cobalt oxide. 3 Iridium, indium,
and applying a solution containing a pyrolyzable salt of tin;
20-70 mol% iridium oxide on the substrate by heating in an oxidizing atmosphere and a total of 80-30 mol%
indium oxide and tin oxide (however, the atomic ratio of indium and tin is 90:10 to 10:90)
A method for producing an electrode for electrolysis, comprising forming a coating having electrocatalytic activity that is substantially a rutile-type composite oxide. 4 A thermally decomposable salt of cobalt was further added to a solution containing thermally decomposable salts of iridium, indium, and tin, and up to 10 mol% of the total amount of indium oxide and tin oxide was replaced with cobalt oxide. The method for manufacturing an electrode for electrolysis according to claim 3, wherein a coating having electrocatalytic activity is formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61078024A JPS62260086A (en) | 1986-04-04 | 1986-04-04 | Electrode for electrolysis and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61078024A JPS62260086A (en) | 1986-04-04 | 1986-04-04 | Electrode for electrolysis and its production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62260086A JPS62260086A (en) | 1987-11-12 |
| JPH0238672B2 true JPH0238672B2 (en) | 1990-08-31 |
Family
ID=13650238
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61078024A Granted JPS62260086A (en) | 1986-04-04 | 1986-04-04 | Electrode for electrolysis and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62260086A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2610230A2 (en) * | 1998-08-31 | 2013-07-03 | Idemitsu Kosan Co., Ltd. | Target for transparent electroconductive film, transparent electroconductive material, transparent electroconductive glass, and transparent electroconductive film |
| JP4476759B2 (en) * | 2004-09-17 | 2010-06-09 | 多摩化学工業株式会社 | Method for producing electrode for electrolysis, and method for producing aqueous quaternary ammonium hydroxide solution using this electrode for electrolysis |
| JP4961825B2 (en) * | 2006-05-09 | 2012-06-27 | アタカ大機株式会社 | Anode for electrochemical reaction |
| JP7330490B2 (en) * | 2019-05-28 | 2023-08-22 | 石福金属興業株式会社 | Electrodes for ozone generation |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59190381A (en) * | 1983-03-11 | 1984-10-29 | ベ−・ベ−・ツエ−・アクチエンゲゼルシヤフト・ブラウン・ボヴエリ・ウント・コンパニイ | Catalyst for coating anode and manufacture |
| JPS60162787A (en) * | 1984-01-31 | 1985-08-24 | Tdk Corp | Electrode for electrolysis |
| JPS6171050A (en) * | 1984-09-14 | 1986-04-11 | 日本遠赤外線株式会社 | Sauna apparatus with water recirculation sterilizing type shower device |
-
1986
- 1986-04-04 JP JP61078024A patent/JPS62260086A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59190381A (en) * | 1983-03-11 | 1984-10-29 | ベ−・ベ−・ツエ−・アクチエンゲゼルシヤフト・ブラウン・ボヴエリ・ウント・コンパニイ | Catalyst for coating anode and manufacture |
| JPS60162787A (en) * | 1984-01-31 | 1985-08-24 | Tdk Corp | Electrode for electrolysis |
| JPS6171050A (en) * | 1984-09-14 | 1986-04-11 | 日本遠赤外線株式会社 | Sauna apparatus with water recirculation sterilizing type shower device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62260086A (en) | 1987-11-12 |
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