JPH0468394B2 - - Google Patents
Info
- Publication number
- JPH0468394B2 JPH0468394B2 JP58171162A JP17116283A JPH0468394B2 JP H0468394 B2 JPH0468394 B2 JP H0468394B2 JP 58171162 A JP58171162 A JP 58171162A JP 17116283 A JP17116283 A JP 17116283A JP H0468394 B2 JPH0468394 B2 JP H0468394B2
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- atomic
- present
- electrolysis
- amorphous alloy
- 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
- 229910000808 amorphous metal alloy Inorganic materials 0.000 claims description 40
- 238000005868 electrolysis reaction Methods 0.000 claims description 32
- 239000007772 electrode material Substances 0.000 claims description 22
- 229910052697 platinum Inorganic materials 0.000 claims description 13
- 229910052703 rhodium Inorganic materials 0.000 claims description 12
- 229910052741 iridium Inorganic materials 0.000 claims description 11
- 229910052707 ruthenium Inorganic materials 0.000 claims description 11
- 229910052726 zirconium Inorganic materials 0.000 claims description 7
- 229910052758 niobium Inorganic materials 0.000 claims description 6
- 229910052715 tantalum Inorganic materials 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 description 43
- 239000000956 alloy Substances 0.000 description 43
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 31
- 238000005260 corrosion Methods 0.000 description 17
- 230000007797 corrosion Effects 0.000 description 17
- 239000000203 mixture Substances 0.000 description 16
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 16
- 239000011780 sodium chloride Substances 0.000 description 16
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 15
- 230000000694 effects Effects 0.000 description 14
- 229910052751 metal Inorganic materials 0.000 description 14
- 239000002184 metal Substances 0.000 description 14
- 230000004913 activation Effects 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 13
- 239000010936 titanium Substances 0.000 description 13
- 239000000243 solution Substances 0.000 description 10
- 230000003197 catalytic effect Effects 0.000 description 9
- 239000000460 chlorine Substances 0.000 description 9
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 8
- 229910052801 chlorine Inorganic materials 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 230000010287 polarization Effects 0.000 description 8
- 239000005708 Sodium hypochlorite Substances 0.000 description 7
- 229910052763 palladium Inorganic materials 0.000 description 7
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 7
- 229910052719 titanium Inorganic materials 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 239000010948 rhodium Substances 0.000 description 6
- 239000013535 sea water Substances 0.000 description 6
- 239000010453 quartz Substances 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 239000010405 anode material Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 230000003213 activating effect Effects 0.000 description 3
- 238000005280 amorphization Methods 0.000 description 3
- 229910052728 basic metal Inorganic materials 0.000 description 3
- 150000003818 basic metals Chemical class 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- -1 chlorine ions Chemical class 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000005300 metallic glass Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 229910002835 Pt–Ir Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 238000002386 leaching Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910001507 metal halide Inorganic materials 0.000 description 2
- 150000005309 metal halides Chemical class 0.000 description 2
- 229910052752 metalloid Inorganic materials 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 229910000566 Platinum-iridium alloy Inorganic materials 0.000 description 1
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910001902 chlorine oxide Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005246 galvanizing Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- HWLDNSXPUQTBOD-UHFFFAOYSA-N platinum-iridium alloy Chemical class [Ir].[Pt] HWLDNSXPUQTBOD-UHFFFAOYSA-N 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C45/00—Amorphous alloys
- C22C45/003—Amorphous alloys with one or more of the noble metals as major constituent
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/383—Hydrogen absorbing alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
- H01M2004/8684—Negative electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0002—Aqueous electrolytes
- H01M2300/0005—Acid electrolytes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
- H01M4/921—Alloys or mixtures with metallic elements
-
- 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
- Y02E60/10—Energy storage using batteries
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Description
本発明は、例えば海水を電解して次亜塩素酸ナ
トリウムを作製するなど比較的稀薄でかつ加熱し
ていない水溶液の電解用陽極材料として好適であ
る表面を活性化した非晶質合金に関するものであ
る。
本発明において「活性化」とは、非晶質金属の
表面にZnを拡散浸透することによつてZnを含む
合金層を表面に作製したのち、アルカリ又は酸溶
液処理によつてZnを選択的に溶解し、表面層を
多孔質化することを言う。
また、本発明において「稀薄溶液」とは0.5M
以下のNaCl水溶液、例えば海水を言う。
従来、チタンなどの耐食性金属上に貴金属を被
覆した電極が知られているが、例えば、海水中で
陽極として用いると剥離しやすく、また耐食性が
低く寿命が短いなどの欠点がある。一方、耐食性
金属上に貴金属酸化物を被覆した電極も用いられ
ているが使用中に酸化物が素地金属から剥離した
り、塩素イオンの酸化と併せて酸素が比較的多量
に発生してエネルギー効率が低いことなどの欠点
がある。
通常、合金は固体状態では結晶化しているが、
合金組成を限定して溶融状態から超急冷凝固させ
ると固体状態でも結晶構造をもたず液体に類似し
た非晶質構造が得られ、このような合金を非晶質
合金という。この非晶質合金は、従来の実用金属
に比べて著しく高い強度を保有し、かつ組成に応
じて異常に高い耐食性をはじめ種々の特性を示
す。
一方本発明者らのうち３人は、先に特許第
1153531号および特願昭55−51115号により電解用
非晶質合金電極材料を発明して出願し、これらの
合金は80℃に加熱したPH４あるいはPH２の
4MNaCl水溶液および80℃に加熱した飽和KCl溶
液の電解用陽極として使用した場合塩素ガスの製
造にはきわめて高い電極解媒活性を示すが、競合
する妨害反応である酸素の発生には不活性であつ
て、効率の高い省エネルギー電極材料であると共
に、高耐食性を備えていることを開示した。
前記特許第1153531号として登録された電解用
非晶質合金電極材料は以下のとおりである：
(1) ＰおよびSiのいずれか１種あるいは２種10〜
40原子％を含み、残部は実質的にPd，Rhおよ
びPtの２種以上からなる電解用非晶質合金電
極材料。
(2) ＰおよびSiのいずれか１種あるいは２種10〜
40原子％を含み、かつRuおよびIrのいずれか
１種あるいは２種20原子％以下を含み、残部は
実質的にPd，RhおよびPtの２種以上からなる
電解用非晶質合金電極材料。
(3) ＰおよびSiのいずれか１種あるいは２種10〜
40原子％を含みかつTi，Zr，NbおよびTaの
いずれか１種または２種以上25原子％以下を含
み、残部は実質的にPd，RhおよびPtの２種以
上からなる電解用非晶質合金電極材料。
(4) ＰおよびSiのいずれか１種または２種10〜40
原子％を含み、かつ、RuおよびIrのいずれか
１種または２種20原子％以下ならびにTi，Zr，
NbおよびTaのいずれか１種または２種以上25
原子％以下を含み、残部は実質的にPd，Rhお
よびPtの１種または２種以上からなる電解用
非晶質合金電極材料。
また、前記特願昭55−51115号により開示した
電解用電極材料は以下のとおりである：
(1) 10〜40原子％のＰおよびSiのいずれか１種あ
るいは２種ならびに20原子％を越えるが80原子
％を越えないIrおよびRuのいずれか１種また
は２種を含み、実質的残部として10原子％以上
Pd，RhおよびPtのいずれか１種あるいは２種
以上を添加して全体を100原子％とする電解用
非晶質合金電極材料。
(2) 10〜40原子％のＰおよびSiのいずれか１種あ
るいは２種ならびに20原子％を越えるが80原子
％を越えないIrおよびRuのいずれか１種ある
いは２種ならびに25原子％以下のTi，Zr，
Nb，Taのいずれか１種または２種以上を含
み、実質的残部として10原子％以上Pd，Rhお
よびPtのいずれか１種または２種以上を添加
して、全体を100原子％とする電解用非晶質合
金電極材料。
本発明者らは前記２つの発明の合金電極材料に
ついて、さらに電極触媒活性を調べた。即ち、80
℃の4M NaCl水溶液より温度が低く、濃度も低
い海水程度の濃度の加熱していないNaCl水溶液
を用い、塩素および水酸化ナトリウムの製造に行
われるような陽極液と陰極液の混合を避ける手段
を採用せずに電解し、陽極で生成する塩素を陰極
で生成する水酸化ナトリウムと直ちに反応させて
次亜塩素酸ナトリウムの製造を試みた。その結
果、常温稀薄な塩化ナトリウム水溶液環境で陽極
室、陰極室を分離することなく次亜塩素酸ナトリ
ウムを製造するというプロセスにおいては、前記
２つの発明の合金電極材料であつても、高い電極
触媒活性を示すことがないということがわかつ
た。例えば、第２図に示すものは前記２つの発明
の合金電極材料が優れた電極特性を示した電解環
境（80℃、4M NaCl，PH４，隔膜電解）でのア
ノード分極曲線と本発明の常温稀薄な電解液環境
（30℃，0.5M NaCl，PH８，無隔膜電解）でのア
ノード分極曲線を同一組成の非晶質合金（41Pd
−40Ir−19P非晶質合金：数字は原子％）で比較
したものであるが、この図を見ても明らかなよう
に塩素が発生することのできる熱力学的平衡電位
（約1.0V）以上で前記２つの発明の電解環境では
急激に塩素発生に伴うアノード電流が上昇してい
るのに対し、本発明のような電解環境では同じ電
極電位、例えば1.2Vでの電流密度を比較すると
２桁も電流密度が下回つている。言い替えれば同
じ材料、同じ反応であつても、異なる環境で用い
ると電極触媒活性が２桁も異なるということがわ
かつた。また、さらに本発明者らは前記２つの発
明の合金電極材料が本発明のような常温稀薄な電
解環境での電極特性がどのように変化するかとい
うことも検討した。その結果、同一合金組成であ
つても塩化ナトリウム濃度が稀薄になるにつれ
て、同じ電極電位での電流密度（単位面積当りの
塩素発生量に比例する因子）が減少する傾向にあ
ることを見いだした。その一例として、第３図、
第４図の分極曲線を示す。これらの図は温度を30
℃一定とし、無隔膜の状態で溶液の濃度だけを変
化させて測定した分極曲線であり、第３図では
56Pd−25Rh−19P非晶質合金について、第４図
では41Pd−40Ir−19P非晶質合金について調べた
ものである。第３図、第４図を見ても明らかなよ
うに、合金組成によつては、塩化ナトリウム溶液
濃度によつて、その電極触媒活性が大きく変化す
る。
また、高い電極触媒活性を示す成分組成の合金
であつても、本発明者らのうち２人がさきに提案
した非晶質金属表面の活性化方法を適用すること
によつて、海水程度の濃度でかつ加熱していない
NaCl水溶液の電解によつて次亜塩素酸ナトリウ
ムを製造するための陽極として優れた電極触媒活
性を有することを新たに見出し、本発明を達成し
た。
例えば、第５図に示すものは本発明の合金に前
記活性化処理を施したものと施さないものの分極
曲線を比較したものであるが、活性化処理を施す
ことにより本発明の合金は1.2Vの電極電位の時
の電流密度が２桁以上、すなわち、塩素発生量が
２桁以上改善されることを見いだしたものであ
る。
本発明はこのような理由からなされたものでそ
の目的は、加熱を特にしていない海水のような稀
薄なNaCl水溶液を陽極室および陰極室に分離す
ることなしに電解し、次亜塩素酸ナトリウムを効
率よく製造し、かつ電解の際十分な耐食性を備え
た陽極材料を提供することにある。
すなわち、本発明は：
(1) ＰおよびSiのいずれか１種または２種10−30
原子％とRu，Rh，IrおよびPtのいずれか１種
または２種以下20−50原子％を含み、残部は実
質的にPd，からなり全体を100原子％とする常
温稀薄溶液電解の陽極用表面活性化非晶質合金
電極材料。
(2) ＰおよびSiのいずれか１種または２種10−30
原子％とRu，Rh，IrおよびPtのいずれか１種
または２種以上20−50原子％を含み、さらに
Ti，Zr，NbおよびTaのいずれか１種または
２種15原子％以下と実質的残部として20原子％
以上のPdからなり全体を100原子％とする常温
稀薄溶液電解の陽極用表面活性化非晶質合金電
極材料。
である。
本発明において、前記組成の溶融合金を超急冷
凝固して得た非晶質合金は、前記各元素が均一に
固溶した単相合金である。元来、特定の化学反応
に対する選択的触媒活性を金属電極に付与するた
めには、有効元素を必要量含む合金を作る必要が
ある。しかし、結晶質金属の場合、多種多量の合
金元素を添加すると、しばしば、化学的性質の異
なる多相構造となり、またこのために機械的強度
を得難いことが多い。これに対し、本発明の非晶
質合金は液体状態から超急冷によつて生成する非
晶質構造であるため、常に均一な単相固溶体とな
り、優れた機械的性質ならびに耐食性を有すると
共に安定かつ均一な電極特性を示す。
一方、電解用電極としての触媒活性を更に高め
るためには、前述した非晶質金属表面の活性化方
法によつて合金表面層にZnなどを拡散浸透させ、
次いで、これをアルカリ溶液に浸出させるなどの
表面活性化処理を施す必要がある。結晶質金属で
はZnなどの拡散浸透が主として結晶粒界で起こ
るため、その後Znなどを浸出させると金属表面
から結晶粒が脱落したり金属が脆化したりするだ
けで、表面活性化処理が有効でない場合が多い。
これに対し、本発明の非晶質合金は、結晶質でな
いため当然ながら結晶粒界にZnなどが優先的に
拡散浸透することになる脆化はおこらないのみな
らず、比較的低温の処理であつても本質的にZn
などの拡散速度が速くかつZnなどが表面層全体
に拡散するため、Znなどの拡散浸透処理後、こ
れらを浸出させると、合金表面全体を十分に活性
化させることができる。
これが、本発明の表面を活性化した非晶質合金
が水溶液電解の陽極材料として優れた特性を保有
する理由である。
なお、Znなどの拡散浸透は、例えばZn粉末中
で合金を熱処理するとか、合金に亜鉛メツキを施
したのち、熱処理を行うなどによつて実現する。
この場合、熱処理温度が高く非晶質合金が結晶化
することは表面を活性化するためには特に支障が
ない。但し、結晶化が進行すると合金が脆化する
場合があるので、結晶化の進行を避けることが望
ましい。
次に、本発明の非晶質合金の製造方法を説明す
る。
本発明の成分組成を有する合金溶湯を溶融状態
から超急冷することにより非晶質合金を製造する
ことができる。冷却速度が遅いと完全に非晶質化
することはできない。したがつて、このような超
急冷を実現できれば、どのような装置であつても
本発明の非晶質合金を製造することが原理的に可
能である。一例として、本発明の非晶質合金を作
製する装置を第１図に示す。図面において２は下
方先端に垂直にノズル３を有する石英管でこの石
英管２の上端に設けられている送入口１より原料
４ならびに原料の酸化を防止する不活性ガスを送
入することができる。前記試料４を加熱するため
石英管２の周囲に加熱炉５を設ける。ノズル３の
垂直下方に高速回転ロール７を設け、これをモー
ター６によつて回転させる。非晶質合金の作製に
は、所定の組成の原料４を石英管２内に入れ不活
性ガス雰囲気下で、加熱炉５によつて加熱溶融
し、モーター６によつて1000〜10000r.p.mで高速
回転しているロール７の外周面上に加圧不活性ガ
スを用いてこの溶湯を噴射させることによつて行
なわれる。この方法によつて、例えば厚さ0.1mm、
幅10mm、長さ数ｍ程度の長い薄板として、本発明
の非晶質合金を得ることができる。
上記方法により作製した本発明の非晶質合金
は、ビツカース硬さが約400〜600、引つ張り強さ
が約120〜200Kg／mm2の範囲にあり、また、完全密
着曲げや冷間圧延（50％以上）が可能な非晶質合
金特有の優れた械械的性質を保有している。
次に本発明合金電極材料の詳細を説明する。
電解用陽極の具備すべき条件は、所定の電気化
学的反応に対する電極触媒能が高くかつ長時間に
わたつて安定であること、この電極反応条件で、
高耐食性と十分な機械的強度を保有することであ
る。合金が非晶質構造を有することは複雑な組成
の合金を単相固溶体として作製することを可能に
すると共に、表面活性化を容易にするため、高く
かつ安定な電極触媒能と高耐食性ならびに優れた
機械的性質を兼ね備えるために必須である。
この非晶質合金の中で、本発明の目的である安
定で高い電極触媒能と高耐食性ならびに優れた機
械的性質を併せて備えた合金は、本発明記載の成
分組成であることを見出した。その例を表１にま
とめて示す。
The present invention relates to a surface-activated amorphous alloy suitable as an anode material for electrolysis of relatively dilute and unheated aqueous solutions, such as the production of sodium hypochlorite by electrolyzing seawater. be. In the present invention, "activation" refers to creating an alloy layer containing Zn on the surface of an amorphous metal by diffusing and infiltrating the surface of the metal, and then selectively removing Zn by treatment with an alkali or acid solution. This means that the surface layer becomes porous. In addition, in the present invention, "dilute solution" is 0.5M
Refers to the following NaCl aqueous solution, such as seawater. Conventionally, electrodes are known in which a noble metal is coated on a corrosion-resistant metal such as titanium, but these electrodes have drawbacks, such as being easy to peel off when used as an anode in seawater, and having low corrosion resistance and short lifespan. On the other hand, electrodes in which a noble metal oxide is coated on a corrosion-resistant metal are also used, but the oxide peels off from the base metal during use, and a relatively large amount of oxygen is generated when chlorine ions are oxidized, resulting in energy efficiency. There are disadvantages such as low Usually, alloys are crystallized in the solid state, but
If the alloy composition is limited and the alloy is ultra-rapidly solidified from a molten state, an amorphous structure similar to that of a liquid without a crystalline structure can be obtained even in the solid state, and such an alloy is called an amorphous alloy. This amorphous alloy has significantly higher strength than conventional practical metals, and exhibits various properties, including unusually high corrosion resistance, depending on its composition. On the other hand, three of the inventors had previously
No. 1153531 and Japanese Patent Application No. 55-51115, he invented and applied for an amorphous alloy electrode material for electrolysis.
When used as an anode for the electrolysis of 4M NaCl aqueous solution and saturated KCl solution heated to 80°C, it exhibits extremely high electrolytic activity for the production of chlorine gas, but is inactive against the competing interfering reaction, the generation of oxygen. It was disclosed that this material is a highly efficient and energy-saving electrode material, and also has high corrosion resistance. The amorphous alloy electrode materials for electrolysis registered as Patent No. 1153531 are as follows: (1) One or both of P and Si10~
An amorphous alloy electrode material for electrolysis containing 40 atomic percent, with the remainder essentially consisting of two or more of Pd, Rh, and Pt. (2) One or both of P and Si10~
An amorphous alloy electrode material for electrolysis containing 40 atomic % and 20 atomic % or less of one or both of Ru and Ir, with the remainder substantially consisting of two or more of Pd, Rh, and Pt. (3) One or both of P and Si10~
An amorphous material for electrolysis containing 40 atomic % and 25 atomic % or less of any one or more of Ti, Zr, Nb, and Ta, and the remainder substantially consisting of two or more of Pd, Rh, and Pt. Alloy electrode material. (4) One or both of P and Si 10 to 40
Contains 20 atomic % or less of any one or both of Ru and Ir, and Ti, Zr,
One or more of Nb and Ta25
An amorphous alloy electrode material for electrolysis containing at least atomic % of Pd, and the remainder substantially consisting of one or more of Pd, Rh, and Pt. Further, the electrode materials for electrolysis disclosed in the above-mentioned Japanese Patent Application No. 55-51115 are as follows: (1) 10 to 40 atomic % of any one or both of P and Si and more than 20 atomic % Contains one or both of Ir and Ru not exceeding 80 atomic %, with the substantial balance being 10 atomic % or more
An amorphous alloy electrode material for electrolysis in which one or more of Pd, Rh and Pt is added to make up 100 atomic %. (2) 10 to 40 atomic % of any one or two of P and Si, more than 20 atomic % but not more than 80 atomic % of any one or two of Ir and Ru, and 25 atomic % or less Ti, Zr,
Electrolysis containing one or more of Nb, Ta, and adding one or more of Pd, Rh, and Pt as a substantial balance of 10 at % or more to make the total 100 at % Amorphous alloy electrode material for use. The present inventors further investigated the electrode catalytic activity of the alloy electrode materials of the two inventions. i.e. 80
By using an unheated NaCl aqueous solution with a concentration similar to that of seawater, which is lower in temperature and concentration than a 4M NaCl aqueous solution at °C, we took measures to avoid mixing the anolyte and catholyte as is done in the production of chlorine and sodium hydroxide. Attempts were made to produce sodium hypochlorite by electrolyzing the chlorine produced at the anode and immediately reacting with sodium hydroxide produced at the cathode. As a result, in the process of producing sodium hypochlorite in an environment of a dilute sodium chloride aqueous solution at room temperature without separating the anode chamber and the cathode chamber, even with the alloy electrode materials of the two inventions mentioned above, a high electrode catalyst It was found that it did not show any activity. For example, Figure 2 shows the anodic polarization curves in the electrolytic environment (80°C, 4M NaCl, PH4, diaphragm electrolysis) in which the alloy electrode materials of the two inventions exhibited excellent electrode properties, and the room-temperature diluted one of the invention. The anode polarization curve in an electrolyte environment (30℃, 0.5M NaCl, PH8, non-diaphragm electrolysis) was compared to that of an amorphous alloy of the same composition (41Pd).
-40Ir-19P amorphous alloy: The numbers are atomic %), but as is clear from this figure, the thermodynamic equilibrium potential (approximately 1.0 V) at which chlorine can be generated is exceeded. In the electrolytic environment of the two inventions mentioned above, the anode current increases rapidly due to chlorine generation, whereas in the electrolytic environment of the present invention, when comparing the current density at the same electrode potential, for example 1.2V, it increases by two orders of magnitude. The current density is also below. In other words, even when using the same material and the same reaction, it was found that the electrocatalytic activity differs by two orders of magnitude when used in different environments. Furthermore, the present inventors also investigated how the electrode properties of the alloy electrode materials of the above two inventions change in a dilute electrolytic environment at room temperature as in the present invention. As a result, they found that even with the same alloy composition, as the sodium chloride concentration becomes dilute, the current density (a factor proportional to the amount of chlorine generated per unit area) at the same electrode potential tends to decrease. As an example, Figure 3,
The polarization curve of FIG. 4 is shown. These figures show the temperature at 30
This is a polarization curve measured by keeping the temperature constant at a constant temperature and changing only the concentration of the solution without a diaphragm.
Regarding the 56Pd-25Rh-19P amorphous alloy, Fig. 4 shows the investigation of the 41Pd-40Ir-19P amorphous alloy. As is clear from FIGS. 3 and 4, depending on the alloy composition, the electrocatalytic activity varies greatly depending on the concentration of the sodium chloride solution. Furthermore, even if the alloy has a composition that exhibits high electrocatalytic activity, by applying the method of activating the amorphous metal surface proposed earlier by two of the present inventors, it is possible to concentrated and not heated
The present invention has been achieved by newly discovering that the anode has excellent electrocatalytic activity as an anode for producing sodium hypochlorite by electrolysis of an aqueous NaCl solution. For example, FIG. 5 shows a comparison of the polarization curves of the alloy of the present invention subjected to the above-mentioned activation treatment and that of the alloy not subjected to the activation treatment. It has been found that the current density at an electrode potential of 2 or more, that is, the amount of chlorine generated is improved by more than 2 orders of magnitude. The present invention was made for this reason, and its purpose is to electrolyze a dilute aqueous NaCl solution such as seawater that has not been heated in particular, without separating it into an anode chamber and a cathode chamber, and to convert it into sodium hypochlorite. An object of the present invention is to provide an anode material that can be efficiently manufactured and has sufficient corrosion resistance during electrolysis. That is, the present invention: (1) Any one or both of P and Si 10-30
For use as an anode for room-temperature dilute solution electrolysis, containing 20-50 atomic % or less of any one or two of Ru, Rh, Ir, and Pt, with the remainder consisting essentially of Pd, making the total 100 atomic %. Surface activated amorphous alloy electrode material. (2) One or both of P and Si 10-30
atomic% and 20-50 atomic% of any one or more of Ru, Rh, Ir and Pt, and further
Any one or both of Ti, Zr, Nb and Ta 15 at% or less and the substantial balance is 20 at%
A surface-activated amorphous alloy electrode material for an anode in room-temperature dilute solution electrolysis, consisting of the above Pd and containing 100 atomic % in total. It is. In the present invention, the amorphous alloy obtained by ultra-rapidly solidifying the molten alloy having the above composition is a single-phase alloy in which each of the above elements is uniformly dissolved in solid solution. Originally, in order to impart selective catalytic activity to a metal electrode for a specific chemical reaction, it is necessary to create an alloy containing the necessary amount of effective elements. However, in the case of crystalline metals, adding a large amount of various alloying elements often results in a multiphase structure with different chemical properties, and for this reason, it is often difficult to obtain mechanical strength. On the other hand, since the amorphous alloy of the present invention has an amorphous structure that is generated by ultra-rapid cooling from a liquid state, it is always a uniform single-phase solid solution, has excellent mechanical properties and corrosion resistance, and is stable and Shows uniform electrode characteristics. On the other hand, in order to further increase the catalytic activity as an electrode for electrolysis, Zn or the like is diffused into the alloy surface layer by the above-mentioned method of activating the amorphous metal surface.
Next, it is necessary to perform a surface activation treatment such as leaching this into an alkaline solution. In crystalline metals, diffusion and penetration of Zn and other substances mainly occurs at grain boundaries, so if Zn and other substances are subsequently leached, the crystal grains will simply fall off from the metal surface or the metal will become brittle, making surface activation treatment ineffective. There are many cases.
On the other hand, since the amorphous alloy of the present invention is not crystalline, it not only does not suffer from embrittlement in which Zn preferentially diffuses into grain boundaries, but also can be processed at relatively low temperatures. Essentially Zn
Since the diffusion rate of Zn and the like is fast and the Zn and the like diffuse throughout the surface layer, the entire alloy surface can be sufficiently activated if these are leached out after Zn and the like are diffused and penetrated. This is the reason why the surface-activated amorphous alloy of the present invention has excellent properties as an anode material for aqueous electrolysis. Note that the diffusion and penetration of Zn and the like is achieved, for example, by heat-treating the alloy in Zn powder, or by heat-treating the alloy after galvanizing it.
In this case, the fact that the heat treatment temperature is high and the amorphous alloy crystallizes does not pose any particular problem in activating the surface. However, since the progress of crystallization may cause the alloy to become brittle, it is desirable to avoid the progress of crystallization. Next, a method for manufacturing the amorphous alloy of the present invention will be explained. An amorphous alloy can be produced by ultra-quenching a molten alloy having the composition of the present invention from a molten state. If the cooling rate is slow, complete amorphization cannot be achieved. Therefore, if such ultra-rapid cooling can be achieved, it is theoretically possible to produce the amorphous alloy of the present invention using any type of equipment. As an example, an apparatus for producing the amorphous alloy of the present invention is shown in FIG. In the drawing, reference numeral 2 denotes a quartz tube having a nozzle 3 vertically at its lower end, through which a raw material 4 and an inert gas for preventing oxidation of the raw material can be introduced through an inlet port 1 provided at the upper end of the quartz tube 2. . A heating furnace 5 is provided around the quartz tube 2 to heat the sample 4. A high speed rotating roll 7 is provided vertically below the nozzle 3 and is rotated by a motor 6. To produce an amorphous alloy, a raw material 4 with a predetermined composition is put into a quartz tube 2, heated and melted in a heating furnace 5 under an inert gas atmosphere, and then heated at 1000 to 10000 rpm by a motor 6. This is carried out by injecting the molten metal onto the outer peripheral surface of the roll 7 which is rotating at high speed using pressurized inert gas. By this method, for example, a thickness of 0.1 mm,
The amorphous alloy of the present invention can be obtained as a long thin plate with a width of 10 mm and a length of several meters. The amorphous alloy of the present invention produced by the above method has a Vickers hardness of about 400 to 600 and a tensile strength of about 120 to 200 Kg/mm 2 , and can be fully contact bent or cold rolled. (50% or more) Possesses excellent mechanical properties unique to amorphous alloys. Next, details of the alloy electrode material of the present invention will be explained. The conditions that an anode for electrolysis must have are that it has a high electrocatalytic ability for a given electrochemical reaction and is stable over a long period of time; under these electrode reaction conditions,
It has high corrosion resistance and sufficient mechanical strength. The amorphous structure of the alloy makes it possible to prepare alloys with complex compositions as single-phase solid solutions, and also facilitates surface activation, resulting in high and stable electrocatalytic ability, high corrosion resistance, and excellent This is essential in order to have both good and mechanical properties. Among these amorphous alloys, it has been found that an alloy having the composition described in the present invention has a stable and high electrocatalytic ability, high corrosion resistance, and excellent mechanical properties, which are the objects of the present invention. . Examples are summarized in Table 1.
【表】【table】
【表】【table】
【表】
本発明の表面を活性化した非晶質合金は、白金
あるいは白金−イリジウム合金を耐食性金属に被
覆した金属電極およびパラジウムなどの酸化物を
耐食性金属に被覆した酸化物電極など実用電極と
比較して極めて優れた特性を保有している。
例えば、海水電解用陽極として使用した場合、
本発明合金の塩素過電圧は前記金属電極および酸
化物電極とほぼ同等であるか成分組成によつては
本発明合金の方がより低く本発明合金は優れた特
性をもつ。
したがつて本発明の表面を活性化した非晶質合
金は、省エネルギー長寿命の電解用陽極材料とし
て優れた特性を具備しており、例えば金属ハロゲ
ン化物水溶液の電解用陽極として広く使用し得
る。
次に本発明における各成分組成を限定する理由
を述べる。
ＰおよびSiは非晶質構造を得るために必要な半
金属元素であり、また、表面保護皮膜の迅速な形
成にも有効な元素である。しかし、ＰおよびSiの
１種または２種の合計が10原子％未満では非晶質
構造を得ることが困難であり、また30原子％を越
えると表面活性化処理を施すと脆化しやすい。し
たがつて10〜30原子％の範囲内にすることが必要
であり、なかでも16〜25原子％の時に非晶質構造
を得ることが特に容易である。なお、従来非晶質
化を助ける半金属元素として知られているＢおよ
びＣは合金を脆化させるため、これら元素によつ
てＰあるいはSiを全量置換することはできない
が、合計約７原子％まで置換することは差し支え
ない。
Pdは、本発明非晶質合金の基本金属であり、
非晶質化しやすく、かつハロゲンイオンの酸化に
特に高い触媒活性を備えた元素である。特に、高
温濃厚塩化ナトリウム水溶液の電解と異なり、本
発明の目的のように稀薄で温度も高くない水溶液
の電解には、とりわけ高い電極触媒活性が必要な
ため、Pdを他の白金族金属で全量置換すること
はできない。したがつて、Pdは本発明の第２項
においても20原子％以上含まなければならない。
Ru，Rh，IrおよびPtはＰおよびSiの１種また
は２種を含む非晶質Pd基合金の耐食性を高める
と共に触媒活性を損わないかあるいはむしろ改善
する元素であつて電解時の耐食性を保証するため
にこれらのいずれか１種または２種以上の合計で
20原子％以上含む必要がある。しかし、Ru，Rh
およびIrを多量に添加すると表面活性化処理を施
しても電極触媒活性が向上しにくく、また表面活
性化によつて脆化しやすくなり、一方Ptの多量
添加は表面活性化による触媒活性の向上を困難に
するため、これらのいずれか１種または２種以上
の合計を50原子％にとどめる必要がある。
Ti，Zr，NbおよびTaは、耐食性を著しく高
め、かつ非晶質化を助ける有効な元素であるが、
これらを多量添加すると表面活性化処理を施して
も触媒活性が向上しにくくなるため、これらのい
ずれか１種または２種以上の合計を15原子％以下
にする必要がある。
以上、本発明の合金は比較的低温で稀薄な金属
ハロゲン化物水溶液の電解のような電極触媒活性
の発揮しにくい条件で陽極として用いる場合、省
エネルギーならびに長寿命の要件、すなわち、高
い電極触媒活性と高耐食性を備えるように、ハロ
ゲンイオンの電解酸化触媒活性の高いPdを基本
金属とし、耐食性の向上に有効なRu，Rh，Ir，
Pt，Ti，Zr，NbおよびTaを適当に配合した非
晶質合金に、さらに電極触媒活性を高めるため表
面活性化処理を施したものであることが特色であ
る。
本発明表面活性化非晶質合金の前記以外の応用
例としては下記のようなものを挙げることができ
る：
１ 上下水減菌用の次亜塩素酸ソーダを製造する
稀薄食塩水の電解用陽極
２ 臭化物電解用の陽極
３ 常温作動型電力貯蔵用電池用陽極
４ 燃料電池用陽極
５ 有機物の電解用陽極
なお少量の他の元素、例えば２原子％程度の
Ｖ，Cr，Mo，Ｗ，Mn，Fe，Co，Ni，Cu，Ag，
Au，Sn，Al，Ge，Ｓなどを含んでも本発明の目
的を達成することができる。
次に本発明を実施例により説明する。
実施例
所定の組成の原料合金を前述の方法で加熱溶解
後超急冷して厚さ0.01〜0.05mm、幅１〜10mm長さ
約３〜20mの非晶質合金薄板を得た。これら非晶
質合金薄板より、所定の長さを切り出し、これに
400g／ZnSO4・7H2Oと70g／Na2SO4からな
る30℃の水溶液中20mA／cm2の一定電流密度でZn
メツキを施した。次いでこれらを200−300℃で30
分間熱処理してZnを拡散浸透させた後加熱した
6M KOH水溶液中でZnを浸出させ試料合金を得
た。このようにして作られた合金を電極として用
い、種々の濃度のNaClを含む30℃の水溶液中動
電位法および定電流法によりアノード分極曲線を
求めた。１例として表２に300℃で熱処理した合
金を用い、0.5N NaCl水溶液中で測定した1.15V
（Saturated Calomel Electrode）における電流
密度をまとめて示した。電流密度の値が大きいも
のほど、次亜塩素酸ソーダ生成の効率が高く、高
性能電極である。[Table] The surface-activated amorphous alloy of the present invention can be used as a practical electrode, such as a metal electrode in which a corrosion-resistant metal is coated with platinum or platinum-iridium alloy, and an oxide electrode in which a corrosion-resistant metal is coated with an oxide such as palladium. It has extremely superior properties in comparison. For example, when used as an anode for seawater electrolysis,
The chlorine overvoltage of the alloy of the present invention is almost the same as that of the metal electrode and the oxide electrode, or depending on the component composition, the alloy of the present invention has a lower chlorine overvoltage, and the alloy of the present invention has excellent characteristics. Therefore, the surface-activated amorphous alloy of the present invention has excellent properties as an energy-saving, long-life anode material for electrolysis, and can be widely used, for example, as an anode for electrolysis of aqueous metal halide solutions. Next, the reason for limiting the composition of each component in the present invention will be described. P and Si are metalloid elements necessary to obtain an amorphous structure, and are also effective elements for rapid formation of a surface protective film. However, if the total content of one or both of P and Si is less than 10 atomic %, it is difficult to obtain an amorphous structure, and if it exceeds 30 atomic %, embrittlement tends to occur when surface activation treatment is performed. Therefore, it is necessary to keep the content within the range of 10 to 30 atom %, and it is especially easy to obtain an amorphous structure when the content is 16 to 25 atom %. Note that B and C, which are conventionally known as metalloid elements that aid in amorphization, embrittle the alloy, so it is not possible to completely replace P or Si with these elements, but a total of about 7 atomic % There is no problem in replacing up to Pd is the basic metal of the amorphous alloy of the present invention,
It is an element that easily becomes amorphous and has particularly high catalytic activity for oxidizing halogen ions. In particular, unlike the electrolysis of high-temperature concentrated sodium chloride aqueous solutions, electrolysis of dilute aqueous solutions whose temperatures are not high as in the purpose of the present invention requires particularly high electrocatalytic activity. It cannot be replaced. Therefore, Pd must be contained in an amount of 20 atom % or more in the second aspect of the present invention as well. Ru, Rh, Ir, and Pt are elements that enhance the corrosion resistance of amorphous Pd-based alloys containing one or both of P and Si, and do not impair or even improve the catalytic activity, and improve the corrosion resistance during electrolysis. Any one of these or the total of two or more
Must contain 20 atomic percent or more. However, Ru, Rh
Adding a large amount of Pt and Ir makes it difficult to improve the electrode catalyst activity even after surface activation treatment, and the surface activation tends to cause embrittlement.On the other hand, adding a large amount of Pt makes it difficult to improve the catalytic activity through surface activation. In order to make it difficult, it is necessary to limit the total amount of one or more of these to 50 atomic %. Ti, Zr, Nb, and Ta are effective elements that significantly improve corrosion resistance and aid in amorphization.
If a large amount of these is added, it becomes difficult to improve the catalytic activity even if surface activation treatment is performed, so the total amount of one or more of these needs to be 15 atomic % or less. As described above, when the alloy of the present invention is used as an anode under conditions where electrocatalytic activity is difficult to exhibit, such as electrolysis of a dilute metal halide aqueous solution at a relatively low temperature, the alloy meets the requirements of energy saving and long life, that is, high electrocatalytic activity. To ensure high corrosion resistance, Pd, which has high halogen ion electrolytic oxidation catalytic activity, is used as the basic metal, and Ru, Rh, Ir, which is effective in improving corrosion resistance, is used as the basic metal.
It is characterized by being made of an amorphous alloy containing an appropriate blend of Pt, Ti, Zr, Nb, and Ta, which has been subjected to surface activation treatment to further enhance the electrode catalyst activity. Examples of applications of the surface-activated amorphous alloy of the present invention other than those mentioned above include the following: 1. Anode for electrolysis of dilute saline water for producing sodium hypochlorite for water and sewage sterilization. 2 Anode for bromide electrolysis 3 Anode for power storage batteries operating at room temperature 4 Anode for fuel cells 5 Anode for electrolysis of organic substances A small amount of other elements, such as about 2 atomic % of V, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Ag,
Even if Au, Sn, Al, Ge, S, etc. are included, the object of the present invention can be achieved. Next, the present invention will be explained by examples. Example A raw material alloy having a predetermined composition was heated and melted by the method described above and then ultra-quenched to obtain an amorphous alloy thin plate having a thickness of 0.01 to 0.05 mm, a width of 1 to 10 mm, and a length of approximately 3 to 20 m. Cut out a predetermined length from these amorphous alloy thin plates, and
Zn at a constant current density of 20 mA/cm 2 in an aqueous solution at 30 °C consisting of 400 g/ZnSO 4 7H 2 O and 70 g/Na 2 SO 4
It was plated. These were then heated at 200-300℃ for 30
Heat treated for 1 minute to diffuse and infiltrate Zn, and then heated.
A sample alloy was obtained by leaching Zn in a 6M KOH aqueous solution. Using the alloy thus prepared as an electrode, anode polarization curves were determined by potentiodynamic and galvanostatic methods in aqueous solutions at 30°C containing various concentrations of NaCl. As an example, Table 2 shows 1.15V measured in a 0.5N NaCl aqueous solution using an alloy heat-treated at 300℃.
(Saturated Calomel Electrode). The larger the current density value is, the higher the efficiency of sodium hypochlorite generation is, and the electrode is a high-performance electrode.
【表】【table】
【表】
極
本発明の表面を活性化した非晶質合金は比較例
としてて示したTi上にPtを被覆したPt／Ti電極
より触媒活性はいずれも高い。また、TiにPdO
を被覆したPdO／Ti電極よりも高いものが大部
分であり、高い活性で知られるPt−Ir／Tiより
優れた電極触媒活性を示すものが数多く見受けら
れる。[Table] Pole The surface-activated amorphous alloy of the present invention has higher catalytic activity than the Pt/Ti electrode shown as a comparative example in which Ti is coated with Pt. Also, PdO on Ti
Most of them have higher electrocatalytic activity than that of PdO/Ti electrodes coated with Pt-Ir/Ti, and many of them show superior electrocatalytic activity to Pt-Ir/Ti, which is known for its high activity.
第１図は本発明非晶質合金を製造する装置の一
例を示す概略図、第２図は公知合金電極材料と本
発明合金電極材料の同一組成非晶質合金のアノー
ド分極曲線の比較グラフ。第３図及び第４図は塩
化ナトリウム濃度の変化に基づく電流密度の減少
を示す比較グラフ、第５図は本発明合金電極材料
の活性化処理の有無による分極曲線の比較グラフ
である。図中、１：原料送入口、２：石英管、
３：ノズル部、４：原料、５：加熱炉、６：モー
ター、７：高速回転ロール。
FIG. 1 is a schematic diagram showing an example of an apparatus for producing the amorphous alloy of the present invention, and FIG. 2 is a graph comparing the anodic polarization curves of an amorphous alloy with the same composition of a known alloy electrode material and an alloy electrode material of the present invention. FIGS. 3 and 4 are comparative graphs showing a decrease in current density based on changes in sodium chloride concentration, and FIG. 5 is a comparative graph of polarization curves of the alloy electrode material of the present invention with and without activation treatment. In the figure, 1: raw material inlet, 2: quartz tube,
3: Nozzle part, 4: Raw material, 5: Heating furnace, 6: Motor, 7: High speed rotating roll.
Claims (1)
原子％とRu，Rh，IrおよびPtのいずれか１種ま
たは２種以上20−50原子％を含み、残部は実質的
にPdからなり全体を100原子％とする常温稀薄溶
液電解の陽極用表面活性化非晶質合金電極材料。 ２ ＰおよびSiのいずれか１種または２種10−30
原子％とRu，Rh，IrおよびPtのいずれか１種ま
たは２種以上20−50原子％を含み、さらにTi，
Zr，NbおよびTaのいずれか１種または２種15原
子％以下と実質的残部として20原子％以上のPd
からなり全体を100原子％とする常温稀薄溶液電
解の陽極用表面活性化非晶質合金電極材料。[Claims] 1 Any one or both of P and Si 10-30
A surface for an anode of room temperature dilute solution electrolysis containing 20-50 atomic % of one or more of Ru, Rh, Ir and Pt, with the remainder being substantially Pd, making the total 100 atomic %. Activated amorphous alloy electrode material. 2 One or both of P and Si 10-30
atomic% and 20-50 atomic% of any one or more of Ru, Rh, Ir, and Pt, and further contains Ti,
Any one or both of Zr, Nb and Ta 15 atomic % or less and Pd as the substantial balance 20 atomic % or more
A surface-activated amorphous alloy electrode material for anodes in room-temperature dilute solution electrolysis, consisting of 100 atomic percent in total.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58171162A JPS6063336A (en) | 1983-09-19 | 1983-09-19 | Surface-activated amorphous alloy for electrode for electrolyzing solution |
| GB08423668A GB2146660B (en) | 1983-09-19 | 1984-09-19 | Surface-activated amorphous alloys for electrodes in the electrolysis of solutions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58171162A JPS6063336A (en) | 1983-09-19 | 1983-09-19 | Surface-activated amorphous alloy for electrode for electrolyzing solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6063336A JPS6063336A (en) | 1985-04-11 |
| JPH0468394B2 true JPH0468394B2 (en) | 1992-11-02 |
Family
ID=15918137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58171162A Granted JPS6063336A (en) | 1983-09-19 | 1983-09-19 | Surface-activated amorphous alloy for electrode for electrolyzing solution |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS6063336A (en) |
| GB (1) | GB2146660B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4781803A (en) * | 1985-02-26 | 1988-11-01 | The Standard Oil Company | Electrolytic processes employing platinum based amorphous metal alloy oxygen anodes |
| CN86105607A (en) * | 1985-06-24 | 1987-02-25 | 标准石油公司 | Novel rhodium based amorphous metal alloys and as the application of halogen electrodes |
| US4705610A (en) * | 1985-06-24 | 1987-11-10 | The Standard Oil Company | Anodes containing iridium based amorphous metal alloys and use thereof as halogen electrodes |
| EP0213708B1 (en) * | 1985-08-02 | 1993-09-22 | Daiki Engineering Co., Ltd. | Surface activated amorphous and supersaturated solid solution alloys for electrodes in the electrolysis of solutions and the method for their surface activation |
| GB2348209B (en) * | 1999-03-24 | 2001-05-09 | Ionex Ltd | Water purification process |
| KR100365095B1 (en) * | 1999-05-15 | 2002-12-18 | 신완철 | An apparatus for producing seawater gas and flammable gas products obtained by using the same |
| GB2508795A (en) * | 2012-09-21 | 2014-06-18 | Ucl Business Plc | Electrolysis electrocatalyst comprising palladium and iridium |
| KR102355824B1 (en) * | 2018-12-27 | 2022-01-26 | 코웨이 주식회사 | Electrode catalyst layer composed of palladium, iridium, and tantalum, and sterilizing water generating module coated with the electrode catalyst |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55152143A (en) * | 1979-05-16 | 1980-11-27 | Toyo Soda Mfg Co Ltd | Amorphous alloy electrode material for electrolysis |
| JPS56150148A (en) * | 1980-04-19 | 1981-11-20 | Toyo Soda Mfg Co Ltd | Electrode material consisting of amorphous alloy suitable for electrolysis |
| JPS57200565A (en) * | 1981-06-03 | 1982-12-08 | Toyo Soda Mfg Co Ltd | Method of activating amorphous metal surface |
-
1983
- 1983-09-19 JP JP58171162A patent/JPS6063336A/en active Granted
-
1984
- 1984-09-19 GB GB08423668A patent/GB2146660B/en not_active Expired
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55152143A (en) * | 1979-05-16 | 1980-11-27 | Toyo Soda Mfg Co Ltd | Amorphous alloy electrode material for electrolysis |
| JPS56150148A (en) * | 1980-04-19 | 1981-11-20 | Toyo Soda Mfg Co Ltd | Electrode material consisting of amorphous alloy suitable for electrolysis |
| JPS57200565A (en) * | 1981-06-03 | 1982-12-08 | Toyo Soda Mfg Co Ltd | Method of activating amorphous metal surface |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6063336A (en) | 1985-04-11 |
| GB2146660A (en) | 1985-04-24 |
| GB2146660B (en) | 1987-05-13 |
| GB8423668D0 (en) | 1984-10-24 |
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