43

沼津工業高等専門学校研究報告
第 52 号，2018 年 1 月஧㓟໬Ⅳ⣲ࡢ㟁Ẽ໬Ꮫⓗ㑏ඖ࡟ࡼࡿࢠ㓟⏕ᡂ࡟࠾ࡅࡿ㖡㟁ᴟ࡬ࡢள㖄ῧຍຠᯝࡢ᳨ウ኱ᓥ୍┿*㸪஭ୖ㯇*㸪኱ᐊᣅᖹ*
Effect of Zn addition to Cu electrode for electrochemical
CO2 reduction to form formic acid
Kazumasa Oshima*, Uruha Inoue*, Takuhei Omuro*
Abstract: For electrochemical CO2 reduction to formic acid, the effect of zinc addition to copper
electrode was investigated. Formic acid, one of practical hydrogen carriers, has high storage
capacity (54 kg-H2 m-3) and stability (b.p.=100ºC). Copper electrode with addition of zinc wasprepared with an electroless co-deposition method. From results, an acid-treatment to theelectrode increased the electrochemical surface area, and a diffusion of the reactant to thesurface. On Cu electrode with 10 mol% Zn addition, the best performance for electrochemical
CO2 reduction was achieved. And SEM images showed that the acid-treatment dissolved theco-deposited zinc, and it form Cu particles, which was an effective active site forelectrochemical CO2 reduction.
Key Words:

Electrochemical CO2 reduction, co-deposition method, Cu electrode䠍䠊⥴㻌 ゝ ㏆ᖺ㸪Ỉ⣲࢚ࢿࣝࢠ࣮♫఍ࢆጞࡵ࡜ࡋࡓ࢚ࢿࣝࢠ࣮ศᩓࡓⓎᒎ㏵ୖᅜ࡛ࡢ㟂せࡀ㧗ࡲࡗ࡚࠸ࡃ≀㉁࡛࠶ࡿ[2,3]㸬᪤Ꮡࡢࢠ㓟〇㐀ࣉࣟࢭࢫࡣ㸪ࢠ㓟࣓ࢳࣝࡢຍỈศゎ࡟ࡼࡗ࡚⾜ࢃࢀ࡚࠸ࡿ(ᘧ 1,2)㸬

ᆺ♫఍࡬ࡢせᮃࡀ㧗ࡲࡗ࡚࠾ࡾ㸪ࡑࡢᇶᖿᢏ⾡࡜࡞ࡿᑠᆺ⿦⨨ࡢ㛤Ⓨࡀ㔜せ࡞ㄢ㢟࡜࡞ࡗ࡚࠸ࡿ㸬ᑠᆺ⿦⨨ࡢタィ࡟

CO + CH3OH → HCOOCH3(ᘧ 1)࠾࠸࡚ࡣ㸪ࢩࢫࢸ࣒ࡢไ⣙ୖ㸪ཎᩱࡢ෌฼⏝ࡸ⇕ᅇ཰ࢆ⤌HCOOCH3 + H2O → HCOOH + CH3OH(ᘧ 2)

ࡳ㎸ࡵࡎ㸪᪤Ꮡࡢ⇕ࢆ㥑ືຊ࡟ࡋࡓ཯ᛂ⣔ࡢᒎ㛤ࡀ㞴ࡋ࠸㸬ࡑࡇ࡛ὀ┠ࡉࢀ࡚࠸ࡿࡢࡀ㸪ᖖ ࡛཯ᛂࡀྍ⬟࡛࠶ࡾ㸪ỗ୍㓟໬Ⅳ⣲࡜࣓ࢱࣀ࣮ࣝࢆᙉሷᇶ୰࡛཯ᛂࡉࡏࡿࡇ࡜࡛⏝ᛶࡢ㧗࠸㟁Ẽࢆ฼⏝ࡋࡓ㟁Ẽ໬Ꮫ཯ᛂ࡟ࡼࡿ≀㉁ኚ᥮

ࢠ㓟࣓ࢳࣝࢆ〇㐀ࡋ㸪ࡑࡢࢠ㓟࣓ࢳࣝࢆຍỈศゎࡍࡿࡇ࡜࡛࠶ࡿ㸬㟁Ꮚࡢ㧗࠸࢚ࢿࣝࢠ࣮ᐦᗘࢆά⏝ࡋࡓ≀㉁ኚ᥮ࡣ㸪࡛㸪ࢠ㓟࡜࣓ࢱࣀ࣮ࣝࢆ〇㐀ࡍࡿ㸬௒ᚋࡢࢠ㓟㟂せࡢቑ኱཯ᛂࡢప ໬࡟ຍ࠼㸪ప⎔ቃ㈇Ⲵࡢࢡ࣮ࣜࣥ࡞ཎᩱ࡬ࡢ㌿

ࢆ㋃ࡲ࠼ࡿ࡜㸪᭷ᐖ࡞୍㓟໬Ⅳ⣲ࡸᙉሷᇶࡣࢢ࣮ࣜࣥࢣ࣑᥮ࡶྍ⬟࡜࡞ࡿ㸬⌧ᅾ㸪Ỉ⣲࢟ࣕࣜ࢔࡜ࡋ࡚㸪ᾮయ࣭ᅽ⦰ࢫࢺ࣮ࣜࡢほⅬ࠿ࡽዲࡲࡋࡃ࡞࠸㸬ࡑࡇ࡛ࢢ࣮ࣜࣥ࡞ཎᩱỈ⣲㸪᭷ᶵࣁ࢖ࢻࣛ࢖ࢻ㸪࢔ࣥࣔࢽ࢔ࡀ⪃࠼ࡽࢀ࡚࠸ࡿ[1]ࢆ⏝࠸ࡓ஧㓟໬Ⅳ⣲ࡢ㟁Ẽ໬Ꮫ㑏ඖ࡟ࡼࡿࢠ㓟〇㐀ࣉࣟࡀ㸪࠸ࡎࢀࡶ୍⯡࡟ᢅ࠺࡟ࡣ༴㝤ࢆక࠺ࡓࡵ㸪ᐙᗞࣞ࣋ࢭࢫࡀ᳨ウࡉࢀ࡚࠸ࡿ[4,5]㸬཯ᛂᘧࢆ௨ୗ࡟♧ࡍ㸬࣭ࣝ⛣ືᘧࣞ࣋ࣝࡲ࡛ᾐ㏱ࡉࡏࡿࡢࡀ㞴ࡋ࠸㸬ࡑࡇ࡛ὀ┠ࡉࢀ࡚࠸ࡿỈ⣲㈓ⶶ࢟ࣕࣜ࢔ࡀࢠ㓟(HCOOH)࡛࠶ࡿ㸬

Anode: H2O → 2H+ + 2e– + 1/2O2

 ࢠ㓟ࡣ㸪ᖖ ᖖᅽ࡛ᾮయ࡛࠶ࡾ㸪⃰ᗘ 78%ᮍ‶࡛ࡣ༴㝤Cathode: CO2≀࡟ヱᙜࡋ࡞࠸ࡓࡵ⛣ືᘧࣞ࣋ࣝ࡬ࡢᒎ㛤ࡀྍ⬟࡛࠶ࡿTotal: CO2 + H2O → HCOOH + 1/2O2(ᘧ 3)+ 2H+ + 2e– → HCOOH

(ᘧ 4)
(ᘧ 5)

[2]㸬ࡲࡓᐙ␆㣫ᩱῧຍ๣ࡸ㜵⭉๣㸪་⸆ရࡢཎᩱ࡜ࡋ࡚ࡶᖺ㛫⣙ 58 ୓ࢺࣥࡢ㟂せࡀ࠶ࡾ㸪௒ᚋࡶ࢔ࢪ࢔ࢆ୰ᚰ࡜ࡋ

Ỉ⣲࢞ࢫࢆỈ⣲※࡜ࡋࡓ◊✲ሗ࿌౛ࡶ࠶ࡾ[6]㸪㏆ᖺ◊✲ࡀ┒ࢇ࡟⾜ࢃࢀ࡚࠸ࡿ[2,3]㸬ᮏࣉࣟࢭࢫࡣ㟁Ẽ໬Ꮫ཯ᛂ࡛࠶*≀㉁ᕤᏛ⛉ࡿࡓࡵᖖ ࡛≀㉁ኚ᥮ࡀྍ⬟࡛࠶ࡾ㸪ࡲࡓཎᩱࡀ஧㓟໬Ⅳ

Department of Chemistry and Biochemistry⣲࠾ࡼࡧỈ࡛࠶ࡿࡇ࡜࠿ࡽ㸪ࢢ࣮ࣜࣥ࡞ࢠ㓟〇㐀ࣉࣟࢭࢫ

44

沼津工業高等専門学校研究報告

第 52 号࡜࡞ࡿ㸬୍᪉࡛๪཯ᛂ࡜ࡋ࡚㸪୍㓟໬Ⅳ⣲ࡸ࣓ࢱࣥࡀ⏕ᡂ

CO2ࡍࡿࡓࡵ㸪ࢠ㓟ࡢ⏕ᡂຠ⋡ࡀప࠸ࡇ࡜ࡀၥ㢟࡜࡞ࡗ࡚࠾ࡾ㸪ࢠ㓟཰⋡ࡢ㧗࠸㟁ᴟᮦᩱࡢ㛤Ⓨࡀㄢ㢟࡜࡞ࡗ࡚࠸ࡿ㸬

Power Supply &Current Monitor ஧㓟໬Ⅳ⣲ࡢ㟁Ẽ໬Ꮫⓗ㑏ඖ࡟ࡼࡿࢠ㓟〇㐀࡟㐺ࡋࡓCupperElectrode(Cathode)㟁ᴟᮦᩱ࡜ࡋ࡚ࡣࠊ㖄ࡸࣅࢫ࣐ࢫ㸪ⓑ㔠ࡀ▱ࡽࢀ࡚࠸ࡿ[4]㸬
ࡋ࠿ࡋ㸪ࡇࢀࡽࡣ༴㝤ᛶ࣭⤒῭ᛶࡢほⅬ࠿ࡽᐇ⏝໬ࡍࡿࡇ

CarbonElectrode(Anode)࡜ࡀ㞴ࡋ࠸㸬୍᪉࡛㸪㖡(Cu)ࡣୖグ࡟ḟࡄάᛶࢆ♧ࡍᮦᩱ࡜ࡋ࡚▱ࡽࢀ࡚࠾ࡾ㸪Ᏻ౯࡛ỗ⏝ᛶ࡟ᐩࢇࡔᮦᩱ࡛࠶ࡿ㸬
1.0 M K2CO3 aq.
(Electrolyte)ࢠ㓟⏕ᡂ㟁ᴟ࡜ࡋ࡚᭦࡞ࡿάᛶྥୖࢆ㐩ᡂࡍࡿࡓࡵ࡟ࡣ㸪ࢼࣀ࡛ࣞ࣋ࣝࡢ⦓ᐦ࡞⾲㠃ᵓ㐀ไᚚࡀ㔜せ࡜࡞ࡿ㸬ࡑࡇ࡛ᅗ 1 ࢠ㓟⏕ᡂホ౯ヨ㦂ࡢ⿦⨨ᴫせᮏ◊✲࡛ࡣ㸪ࢠ㓟⏕ᡂ࡟㐺ࡋࡓ㖡ᚤ⢏Ꮚ㟁ᴟࢆㄪ〇ࡍࡿࡇ࡜ࢆ┠ⓗ࡜ࡋ࡚㸪㖡㟁ᴟࡢ↓㟁ゎࡵࡗࡁㄪ〇࡬ࡢள㖄ῧຍຠᯝࢆ᳨ウࡍࡿ㸬ள㖄࡜㖡ࡢ㓟࡬ࡢ⁐ゎᛶࡢ㐪࠸ࢆ฼⏝ࡍࡿࡇ࡜࡛㸪ඹࡵࡗࡁᚋ࡟ள㖄ࡔࡅࢆ㑅ᢥⓗ࡟ྲྀࡾ㝖ࡁ㸪ෆ㒊ᣑᩓᛶࢆ᭷ࡋࡓ㖡ࢼࣀ⢏Ꮚ㟁ᴟࢆㄪ〇ࡍࡿࡇ࡜ࢆ≺࠺㸬䠏䠊⤖ᯝ䛚䜘䜃⪃ᐹ㸱㸬㸯 ᨭᣢయࡢ㑅ᐃ࠾ࡼࡧ㖡ࡵࡗࡁࡢ᳨ウ ᮏ⣔࡟㐺ࡋࡓ㟁ᴟᨭᣢయࢆ㑅ᐃࡍࡿࡓࡵ㸪ྛ✀㟁ᴟᲬࢆ⏝࠸࡚㸪Ⅳ㓟࣒࢝ࣜ࢘Ỉ⁐ᾮ୰࡛ࡢ㟁ὶ≉ᛶࢆホ౯ࡋࡓ㸬䠎䠊ᐇ㦂᧯సࡑࡢ⤖ᯝࢆ⾲ 1 ࡟♧ࡍ㸬ࢽࢵࢣࣝ(Ni)ࡸ㖡(Cu)ࡣ㸪ึᮇ㟁ὶ್ࡣ㧗࠸ࡶࡢࡢ㸪ᨭᣢయ⾲㠃࡟୙ᑟయ⿕⭷ࡀᙧᡂࡉࢀࡓ㸰㸬㸯 㟁ᴟㄪ〇㟁ᴟࡣ㸪㔠ᒓᲬࡢᨭᣢయ(4 mmI)ୖ࡟↓㟁ゎࡵࡗࡁἲ࡟ࡓࡵ㸪㟁ᅽ༳ຍᚋ 300 min ࡛ࡣ㟁ὶ್ࡀ኱ᖜ࡟ῶᑡࡋࡓ㸬ࡼࡾㄪ〇ࡋࡓ㸬⵨␃Ỉ࡟◪㓟㖡࣭୕Ỉ࿴≀(Cu(NO3)2࣭3H2O)ࠊ

ࡲࡓ┿㘷(Brass)ࡸࢪ࣑ࣗࣛࣝࣥ(Duralumin)ࡣึᮇ࠿ࡽప࠸

Ⅳ㓟ࢼࢺ࣒ࣜ࢘(Na2CO3)㸪㓇▼㓟ࢼࢺ࣒࣒ࣜ࢘࢝ࣜ࢘

㟁ὶ್ࢆ♧ࡋࠊᮏ⣔ࡢ㟁ᴟᨭᣢయ࡜ࡋ࡚ࡣ㐺ࡉ࡞࠸ࡇ࡜ࡀ

(KNaC4H4O6࣭4H2O)㸪Ỉ㓟໬ࢼࢺ࣒ࣜ࢘(NaOH)ࢆ⁐ゎࡉࡏศ࠿ࡗࡓ㸬ࡇࢀࡽ࡟ᑐࡋ࡚㕲(Fe)ࡣ㸪⾲ 1 ࡟♧ࡍ㏻ࡾ㸪㧗ࡓ㸬ㄪ〇ࡋࡓ⁐ᾮ࡟ᨭᣢయ࡜࡞ࡿ㔠ᒓᲬࢆᾐₕࡉࡏ㸪㑏ඖ࠸㟁ὶ್ࢆᏳᐃࡋ࡚♧ࡍࡇ࡜ࡀศ࠿ࡗࡓ㸬ᮏ⤖ᯝࡼࡾ㸪ᨭ๣࡜ࡋ࡚࣒࣍ࣝ࢔ࣝࢹࣄࢻ(HCHO)ࢆ 1 mL minᣢయ࡜ࡋ࡚㕲(Fe rod)ࢆ᥇⏝ࡋ㸪㖡ࡵࡗࡁࡢຠᯝ࡟ࡘ࠸᳨࡚ῧຍࡋࡓ㸬ᨭᣢయࢆᾐₕࡉࡏࡓࡲࡲ 10 h ಖᣢࡋ㸪ỈὙ࣭஝ウࡍࡿࡇ࡜࡜ࡋࡓ㸬-1 ࡢ㏿ᗘ࡛

⇱ࡉࡏࡿࡇ࡜࡛㔠ᒓ㖡ࢆᨭᣢయ⾲㠃࡟ᢸᣢࡉࡏࡓ㸬㖡ᚤ⢏Ꮚ㟁ᴟࡢㄪ〇࡟࠾࠸࡚ࡣ㸪ள㖄ࡢ๓㥑య࡜ࡋ࡚◪㓟ள㖄࣭භỈ࿴≀(Zn(NO3)2࣭6H2O)ࢆῧຍࡋ㸪㖡࡜ள㖄ࢆ⾲ 1 ྛ㟁ᴟᨭᣢయࡢⅣ㓟࣒࢝ࣜ࢘୰࡛ࡢ㟁ὶ≉ᛶElectrodeඹࡵࡗࡁࡋࡓ㸬ࡉࡽ࡟ྲྀࡾฟࡋࡓ㟁ᴟࢆ㸪3.0 M ࡢᕼሷ㓟Current / mA0 min

300 minFormic Acid / Pmol

࡟ 10 min ᾐₕࡉࡏ㸪ỈὙ࣭஝⇱ࡉࡏࡿࡇ࡜࡛ள㖄ࢆ⁐ฟࡉ

Fe

48.3

34.90.0ࡏ࡚㖡ᚤ⢏Ꮚ㟁ᴟࢆㄪ〇ࡋࡓ㸬㓟ฎ⌮๓ᚋࡢ SEM ࠾ࡼࡧ

Ni

50.5

6.2

0.0

EDS ほᐹ࡟ࡼࡾ㸪㖡ᚤ⢏Ꮚ⢏Ꮚࢆホ౯ࡋࡓ㸬

Cu

21.8

5.9

0.0

Brass12.4

9.50.0㸰㸬㸰 㟁ᴟᛶ⬟ヨ㦂

Duralumin

6.2

6.50.0 ㄪ〇ࡋࡓ㟁ᴟࡢホ౯࡜ࡋ࡚㸪஧㓟໬Ⅳ⣲ࡢ㟁Ẽ໬Ꮫ㑏ඖ࡟ࡼࡿࢠ㓟⏕ᡂヨ㦂ࢆᐇ᪋ࡋࡓ㸬ᐇ㦂⿦⨨ᴫせࢆᅗ 1 ࡟♧㟁ᴟ⾲㠃✚ࡢྥୖ࡟ࡼࡿ㟁ὶ್ୖ᪼㸪࠾ࡼࡧࢠ㓟⏕ᡂάࡍ㸬ᅄࡘཱྀࣇࣛࢫࢥ࡟㸪㟁ゎᾮ࡜ࡋ࡚ 1.0 M Ⅳ㓟࣒࢝ࣜ࢘

ᛶࡢⓎ⌧ࢆ≺࠸㸪㕲ᨭᣢయ࡟㔠ᒓ㖡ࢆࡵࡗࡁࡋࡓ㟁ᴟ(Cu /Ỉ⁐ᾮ(K2CO3)ࢆຍ࠼㸪࢝ࢯ࣮ࢻ࡟ㄪ〇ࡋࡓ㖡㟁ᴟ㸪࢔ࣀFe rod)ࢆㄪ〇ࡋࡓ㸬㖡㟁ᴟᲬ(Cu rod)࡜ẚ㍑ࡋ࡚㟁ὶ್ࡣྥ

࣮ࢻ࡟Ⅳ⣲Წ(4 mmI)ࢆタ⨨ࡋࡓ㸬཯ᛂ ᗘࡣ 303 K ࡜ࡋ㸪ୖࡋࡓࡇ࡜࠿ࡽ㸪㔠ᒓ㖡ࡢ⾲㠃✚ྥୖ࡟ࡼࡿ㟁ὶ್ୖ᪼ࢆ

2.5 V ࢆ 300 min ༳ຍࡋࡓ㸬ཎᩱ࡛࠶ࡿ஧㓟໬Ⅳ⣲ࡣ㐣๫㔞㐩ᡂࡋࡓ㸬ࡋ࠿ࡋ཯ᛂᚋ⁐ᾮ୰࠿ࡽࢠ㓟ࡣ᳨ฟࡉࢀࡎ㸪ࢠࢆࣂࣈࣜࣥࢢ࡟ࡼࡾ౪⤥ࡋࡓ㸬཯ᛂ୰ࡢ㟁ὶ್࠾ࡼࡧ཯ᛂ㓟⏕ᡂ㟁ᴟ࡜ࡋ࡚ࡣ᭦࡞ࡿ᳨ウࡀᚲせ࡛࠶ࡿࡇ࡜ࡀࢃ࠿ᚋࡢ⁐ᾮ୰࡟ྵࡲࢀࡿࢠ㓟㔞࠿ࡽ㸪㖡㟁ᴟࡢࢠ㓟⏕ᡂ཯ᛂࡗࡓ㸬ࡑࡇ࡛㖡㟁ᴟࡢᚤ⢏Ꮚ໬࡟ࡼࡿࢠ㓟⏕ᡂࢧ࢖ࢺࡢ๰

࡟ᑐࡍࡿάᛶࢆホ౯ࡋࡓ㸬࡞࠾ࢠ㓟ࡢᐃᛶ࣭ᐃ㔞ࡣฟࢆ≺࠸㸪㖡ࡵࡗࡁ࡬ࡢள㖄ῧຍຠᯝࢆ᳨ウࡋࡓ㸬

GC-TCD ࢆ⏝࠸࡚⾜ࡗࡓ㸬二酸化炭素の電気化学的還元によるギ酸生成における銅電極への亜鉛添加効果の検討45⾲㠃≧ែほᐹࢆ⾜ࡗࡓ㸬㓟ฎ⌮๓ᚋࡢ SEM ࠾ࡼࡧ EDS ඖ100⣲ศᯒࡢ⤖ᯝࢆᅗ 3 ࡟♧ࡍ㸬㓟ฎ⌮๓ࡣ㖡ࡀ୍ᵝ࡟ᨭᣢయ45.1 Pmol80⾲㠃࡟Ꮡᅾࡋ࡚࠸ࡿࡢ࡟ᑐࡋ࡚㸪㓟ฎ⌮ᚋ࡟ࡣள㖄ࡀ⁐ฟCurrent / mAࡋ㸪㖡ࡢᚤ⢏Ꮚࡀᙧᡂࡉࢀ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡗࡓ㸬ࡲࡓᨭCu / Fe rod
10Zn-Cu / Fe (as made)10Zn-Cu / Fe (acid)60

40ᣢయ࡛࠶ࡿ㕲ࡶ㢧ⴭ࡟᳨ฟࡉࢀ࡚࠾ࡾ㸪㓟ฎ⌮࡟ࡼࡗ࡚࣑ࢡࣟ⣽Ꮝࡀᙧᡂࡋ㸪཯ᛂ≀ࡢ㟁ᴟෆ㒊࡬ࡢᣑᩓᛶ࠾ࡼࡧ㟁Ⲵ⛣ືࡀྥୖࡋࡓ࡜⪃࠼ࡽࢀࡿ㸬┠ⓗ࡜ࡋ࡚࠸ࡓࢼࣀ⢏Ꮚࡢᙧᡂ࡟ࡣ⮳ࡽ࡞࠿ࡗࡓࡶࡢࡢ㸪SEM ീࡼࡾᚤ⢏Ꮚᙧᡂ࡟200ࡼࡿ⾲㠃✚ྥୖ࠾ࡼࡧᣑᩓᛶྥୖࡣ☜ㄆࡉࢀࡓ㸬ḟ࡟㸪ள㖄ῧຍ㔞ࡢ᭱㐺್ࢆ᳨ウࡍࡿࡓࡵ㸪ඹࡵࡗࡁ࡟
050

100

150

200

250

Time on stream / min300

࠾ࡅࡿ㖡࡟ᑐࡍࡿள㖄ῧຍ๭ྜࢆ᳨ウࡋࡓ㸬ࡑࡢ⤖ᯝࢆᅗ
4 ࡟♧ࡍ㸬ซ౛ࡢ๓ࡢᩘ್ࡀள㖄ῧຍ๭ྜࢆ♧ࡋ࡚࠾ࡾ㸪ᅗ 2 㖡㟁ᴟ࡬ࡢள㖄ῧຍຠᯝ࠾ࡼࡧ㓟ฎ⌮ຠᯝࡑࢀࡒࢀ㖡࡟ᑐࡋ࡚ 1 mol%㸪10 mol%㸪100 mol%ࡢ 3 ࡘࡢῧຍ㔞ࢆヨ㦂ࡋࡓ㸬࡞࠾࠸ࡎࢀࡢ㟁ᴟ࡟࠾࠸࡚ࡶ㓟ฎ⌮ࢆ⾜ࡗ࡚࠸ࡿ㸬ᅗ 4 ࡟♧ࡍ㏻ࡾ㸪㖡࡟ᑐࡋ࡚ 10 mol%ள㖄ࢆ㸱㸬㸰 㖡ࡵࡗࡁ࡬ࡢள㖄ῧຍຠᯝࡢ᳨ウ㖡ࡵࡗࡁ㟁ᴟ(Cu / Fe rod)࡛ࡣࢠ㓟⏕ᡂάᛶࢆ♧ࡉ࡞࠿ῧຍࡋࡓ㟁ᴟ(10Zn-Cu / Fe (acid))ࡀ᭱ࡶ㧗࠸㟁ὶ್࠾ࡼࡧࡗࡓࡇ࡜࠿ࡽ㸪㖡࣭ள㖄ࡢඹࡵࡗࡁᚋ࡟ள㖄ࢆ㓟㝖ཤࡍࡿࢠ㓟⏕ᡂάᛶࢆ♧ࡋࡓ㸬ள㖄ῧຍ 10 mol%࡛ᴟ኱ࢆ♧ࡋࡓࡇ࡜࡛ள㖄ࢆ⁐ฟࡉࡏ㸪ࢼࣀࢧ࢖ࢬ⢏Ꮚࢆ᭷ࡍࡿ㖡ᚤ⢏Ꮚ⌮⏤ࢆ᳨ウࡍࡿࡓࡵ㸪1 mol%࠾ࡼࡧ 100 mol㸣ࡢ㓟ฎ⌮ᚋ㟁ᴟࡢㄪ〇ࢆ≺ࡗࡓ㸬ᅗ 2 ࡟㖡ࡵࡗࡁ㟁ᴟ࡬ࡢள㖄ῧຍຠࡢ SEM ほᐹࢆ⾜ࡗࡓ㸬ள㖄ῧຍ 1 mol%࡛ࡣ㸪⁐ฟࡍࡿளᯝࢆ♧ࡍ㸬ᮍ㓟ฎ⌮ࡢள㖄ඹࡵࡗࡁࡢ㟁ᴟ(10Zn-Cu / Fe (as㖄㔞ࡀᑡ࡞࠸ࡓࡵ࡟㸪༑ศ࡞࣑ࢡࣟ⣽Ꮝࡢᙧᡂࡀ☜ㄆࡉࢀmade))࡟࠾࠸࡚ࡣ㸪㖡ࡵࡗࡁ㟁ᴟ(Cu / Fe rod)࡜ྠᵝࡢ㟁ὶ࡞࠿ࡗࡓ㸬ࡑࡢࡓࡵ⾲㠃✚࠾ࡼࡧᣑᩓᛶࡀ༑ศ࡟ྥୖࡏࡎ㸪≉ᛶࢆ♧ࡋ㸪ࢠ㓟⏕ᡂάᛶࢆ♧ࡉ࡞࠿ࡗࡓ㸬ࡇࡢ⤖ᯝࡼࡾ㸪㟁ὶ್ࡢྥୖࡀ㐩ᡂࡉࢀ࡞࠿ࡗࡓ࡜⪃࠼ࡽࢀࡿ㸬୍᪉࡛㸪ῧຍࡋࡓள㖄ࡣ㟁Ẽⓗ≉ᛶ࠾ࡼࡧࢠ㓟⏕ᡂ࡟ࡣ୙άᛶ࡛

ள㖄ῧຍ 100 mol%࡛ࡣ 100 Pm ௨ୖࡢᕧ኱໬ࡋࡓ㖡⢏Ꮚࡀ࠶ࡿࡇ࡜ࡀ♧၀ࡉࢀࡓ㸬ࡇࢀ࡟ᑐࡋ࡚㸪㓟ฎ⌮࡟ࡼࡗ࡚ளほ ࡉࢀࡓ㸬㐣๫㔞ࡢள㖄⁐ฟ࡟కࡗ࡚㖡ࡶ⁐ฟࡋ㸪㟁ᴟ㖄㝖ཤࡋࡓ㟁ᴟ(10Zn-Cu / Fe (acid))ࡣ㸪㟁ὶ್ࡀ኱ᖜ࡟ྥᨭᣢయୖ࡟෌ᯒฟࡋࡓ࡜⪃࠼ࡽࢀࡿ㸬ࡇࡢᕧ኱⢏ᏊࡢᏑᅾୖࡋ㸪㖡ࡵࡗࡁ㟁ᴟ(Cu / Fe rod)࡜ẚ㍑ࡋ࡚⣙ 4 ಸࡢ㟁ὶ್࡟ࡼࡾ㸪⾲㠃✚࠾ࡼࡧᣑᩓᛶࡀ༑ศ࡟ྥୖࡏࡎ㸪ࢠ㓟⏕ᡂࢆ♧ࡋࡓ㸬ࡲࡓ཯ᛂᚋࡢ⁐ᾮ࠿ࡽ 45.1 Pmol ࡢࢠ㓟⏕ᡂࢆάᛶࡀྥୖࡋ࡞࠿ࡗࡓ࡜⪃࠼ࡽࢀࡿ㸬௨ୖࡢ⤖ᯝࡼࡾ㸪㖡☜ㄆࡋࡓ㸬ࡇࡢ⤖ᯝ࠿ࡽ㸪㖡ᚤ⢏Ꮚ㟁ᴟࢆ⏝࠸ࡿࡇ࡜࡛஧ᚤ⢏Ꮚᙧᡂ࡟㐺ࡋࡓள㖄ῧຍ㔞ࡣ㸪㖡࡟ᑐࡋ࡚ 10 mol%࡛㓟໬Ⅳ⣲ࡢ㑏ඖࡀ㐍⾜ࡋ㸪ࢠ㓟⏕ᡂάᛶࢆ♧ࡍࡇ࡜ࡀ᫂ࡽ࠶ࡿࡇ࡜ࡀศ࠿ࡗࡓ㸬࠿࡟࡞ࡗࡓ㸬ᚤ⢏Ꮚࡢᙧᡂࢆ☜ㄆࡍࡿࡓࡵ࡟㸪SEM ࡟ࡼࡿ

Before Acid-treatment

Cu

After Acid-treatment

Cuᅗ 3 ள㖄ῧຍ㖡㟁ᴟࡢ㓟ฎ⌮๓ᚋࡢ SEM ീ࠾ࡼࡧ EDS ඖ⣲ศᯒ

Fe

46

沼津工業高等専門学校研究報告

第 52 号

⾲ 2 ྛ㖡㸫ள㖄ඹࡵࡗࡁ㟁ᴟࡢࢠ㓟⏕ᡂヨ㦂⤖ᯝࡢࡲ࡜ࡵ
ElectrodeCu weight / mg cm-2

Current / mA

Formic Acid / Pmol

Formic Acid / Pmol mg-1 Selectivity* / %Cu/Fe rod

12.3

27.1

0.0

0.0

0.0

10Zn-Cu/Fe (as made)N.D.

22.80.0

N.D.

0.0

1Zn-Cu/Fe (acid)

13.5

51.8

43.0

0.6

6.7

10Zn-Cu/Fe (acid)

3.46

82.5

45.1

2.6

4.4

100Zn-Cu/Fe (acid)

11.7

51.3

14.0

0.2

2.2

*㸸㏻㟁ࡋࡓ㟁Ꮚ࡟࠾ࡅࡿࢠ㓟⏕ᡂ࡟ᐤ୚ࡋࡓ๭ྜ㸬௨ୖࡢ⤖ᯝࢆ⾲ 2 ࡟ࡲ࡜ࡵࡿ㸬⾲ 2 ࡢ㑅ᢥ⋡ࡣ㸪㟁ὶ್࡜ࢠ㓟⏕ᡂ㔞ࡢẚ࠿ࡽ㸪ࢠ㓟⏕ᡂ࡟ᾘ㈝ࡋࡓ㟁Ꮚࡢ๭ྜࢆ䠐䠊⤖㻌 ㄽ♧ࡋ࡚࠸ࡿ㸬ᘧ 3-5 ࡟♧ࡍ㏻ࡾ㸪ࢠ㓟 1 ศᏊࡢ⏕ᡂ࡟ࡣ 2㟁Ẽ໬Ꮫⓗ࡞஧㓟໬Ⅳ⣲㑏ඖ࡟ࡼࡿࢠ㓟⏕ᡂࡢࡓࡵ㸪⾲㟁Ꮚࢆせࡍࡿࡇ࡜ࡀศ࠿ࡗ࡚࠾ࡾ㸪ࡑࢀࢆຍ࿡ࡋ࡚㟁Ꮚࡢ㠃✚ྥୖ࣭≀㉁ᣑᩓྥୖࢆ≺ࡗࡓ㖡ᚤ⢏Ꮚ㟁ᴟࢆㄪ〇ࡋࡓ㸬ኚ᥮๭ྜ(㑅ᢥ⋡)ࢆᑟฟࡋ࡚࠸ࡿ㸬࡞࠾๪཯ᛂ࡜ࡋ࡚ࡣỈࡑࡢ⤖ᯝ㸪㖡࡜ள㖄ࢆඹࡵࡗࡁࡋࡓ Zn-Cu / Fe rod ࡟ᑐࡋศゎࡀ㐍⾜ࡋ࡚࠾ࡾ㸪ᢞධࡋࡓ㟁Ꮚࡢ኱༙ࡣỈศゎ࡟ᾘ㈝࡚㓟ฎ⌮ࢆ⾜࠺ࡇ࡜࡛㸪ඹࡵࡗࡁࡋࡓள㖄ࡀ⁐ฟࡋ㸪㖡ᚤࡉࢀ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡗࡓ㸬ࢠ㓟⏕ᡂ㔞ࢆẚ㍑ࡍࡿ࡜㸪ඛ⢏Ꮚࡀᙧᡂࡉࢀࡿࡇ࡜ࡀࢃ࠿ࡗࡓ㸬ࡲࡓᮏ㟁ᴟࡣ㸪஧㓟໬

㏙ࡢ㏻ࡾ 10Zn-Cu / Fe (acid)ࡀ᭱ࡶ㧗࠸್ࢆ♧ࡋ࡚࠾ࡾ㸪㖡Ⅳ⣲ࡢ㟁Ẽ໬Ꮫⓗ㑏ඖ࡟᭷ຠ࡛࠶ࡾ㸪ࢠ㓟ࡢ⏕ᡂࡀ☜ㄆࡉᢸᣢ㔞࠶ࡓࡾࡢࢠ㓟⏕ᡂ㔞࡛ẚ㍑ࡋ࡚ࡶ᭱ࡶ㧗࠸್ࢆ♧ࢀࡓ㸬ࡲࡓள㖄ῧຍ㔞ࢆ᳨ウࡋࡓ⤖ᯝ㸪㖡࡟ᑐࡋ࡚ 10 mol%ࡋࡓ㸬ࡇࡢࡇ࡜࠿ࡽள㖄ῧຍ 10 mol%࡛ࡣ㸪ᮏ┠ⓗ࡟㐺ࡋࡢள㖄ࢆῧຍࡋࡓ 10 Zn-Cu / Fe (acid)ࡀ᭱ࡶ㧗࠸ࢠ㓟⏕ᡂࡓள㖄⁐ฟ࣭㖡ᚤ⢏Ꮚ໬ࡀ㐩ᡂࡉࢀ㸪≀㉁ᣑᩓ࣭㟁Ⲵ⛣ືάᛶࢆ♧ࡋࡓ㸬㐺ษ࡞ள㖄ῧຍ࣭㓟ฎ⌮࡟ࡼࡾ㸪㔠ᒓ㖡ࡢࡀ኱ᖜ࡟ྥୖࡋ࡚࠸ࡿࡇ࡜ࡀ♧ࡉࢀࡓ㸬୍᪉㸪㑅ᢥ⋡࡛ࡣᚤ⢏Ꮚ໬࠾ࡼࡧ࣑ࢡࣟ⣽Ꮝࡢᙧᡂࡀ㐩ᡂࡉࢀࡓࡓࡵ࡟㸪⾲

1Zn-Cu / Fe (acid)ࡀ᭱ࡶ㧗࠸್ࢆ♧ࡋࡓ㸬ࡇࡢ⤖ᯝ࠿ࡽ㸪ࢠ㠃✚࠾ࡼࡧ≀㉁ᣑᩓࡀྥୖࡋ㸪ࢠ㓟⏕ᡂࡀ㐩ᡂࡉࢀࡓ㸬㓟⏕ᡂࡢ㑅ᢥ⋡࡟࠾࠸࡚ࡣ㸪㟁ᴟࡢ⾲㠃ᙧ≧ࡀ㔜せ࡛࠶ࡿࡇ࡜ࡀศ࠿ࡗࡓ㸬ࡍ࡞ࢃࡕ㸪㧗࠸ࢠ㓟཰⋡ࢆ㐩ᡂࡍࡿࡓࡵ࡟ࡣ㸪≀㉁ᣑᩓ࣭㟁Ⲵ⛣ືࡢྥୖ࡟ຍ࠼㸪⾲㠃ᙧ≧ࡢไᚚ[1] ෆ㛶ᗓࠕᡓ␎ⓗ࢖ࣀ࣮࣋ࢩࣙࣥ๰㐀ࣉࣟࢢ࣒ࣛ(SIP)ࡀ㔜せ࡛࠶ࡿࡇ࡜ࡀศ࠿ࡗࡓ㸬Cu / Fe rod1Zn-Cu / Fe (acid)
10Zn-Cu / Fe (acid)
100Zn-Cu / Fe (acid)100࢚ࢿࣝࢠ࣮࢟ࣕࣜ࢔◊✲㛤Ⓨィ⏬ࠖ㸪2017.4.1.
[2] Y. Himeda, S. Miyazawa, T. Hirose, ChemSusChem, 4 (2011)487.
[3] Aligoli Amir Nazmi Afshar Chemical Profile: Formic acid80

Current / mA䠑䠊ཧ⪃ᩥ⊩

60

45.1 Pmol(2014)

43.0 Pmol[4] K. Hara, A. Kudo, T. Sakata, J. Electroana. Chem., 391

14.0 Pmol

40(1995) 141.
[5] M. Jitaru, D.A. Lowy, M. Toma, B.C. Toma, L. Oniciu, J.
Appl. Electrochem., 27 (1997) 875.

200[6] ᕤ⸨ Ύ㸪ᮡ⏣ಙஅ㸪➉ᓮ჆┿㸪᪥ᮏ໬Ꮫ఍ㄅ㸪3 (1977)
302.
050

100

150

200

250

Time on stream / min300

ᅗ 4 ள㖄ῧຍ㖡㟁ᴟࡢள㖄ῧຍ㔞ࡢᙳ㡪