2010B1780                           BL14B2㓟⣲㑏ඖ⬟ࢆ᭷ࡍࡿⅣ⣲ⷧ⭷࡟࠾ࡅࡿάᛶⅬᵓ㐀ࡢ
XAFS ᐃ࡟ࡼࡿศᯒAnalysis of active site by XAFS in carbon thin filmwith catalytic activity for oxygen reductionb, ᇛ㛫 ⣧ c୸ᒣ ⣧ a, ᕊ㔜aJun Maruyama , Atsushi Mineshigeb, Zyun Siromaca㻔ᆅ⊂㻕኱㜰ᕷ❧ᕤᴗ◊✲ᡤ, b රᗜ┴❧኱Ꮫ኱Ꮫ㝔, c㻔⊂㻕⏘ᴗᢏ⾡⥲ྜ◊✲ᡤ
 aOsaka Municipal Technical Research Institute, bUniversity of Hyogo,
cNational Institute of Advanced Industrial Science and Technologyᅛయ㧗ศᏊᆺ⇞ᩱ㟁ụࡢᮏ᱁ⓗᬑཬࡢᐇ⌧࡟㈉⊩ࡍࡿ࡜ᮇᚅࡉࢀࡿ㠀㈗㔠ᒓ⣔ṇᴟゐ፹ࡢ᪂ࡓ࡞〇ἲ࡜ࡋ࡚ࠊ⡆᫆ⓗ࡛ࡣ࠶ࡿࡀ㕲ࣇࢱࣟࢩ࢔ࢽࣥ࠿ࡽࣁ࢖ࣈࣜࢵࢻ≀⌮໬ᏛẼ┦ᡂ㛗ἲ࡟ࡼࡾ㕲ࢆྵ᭷ࡍࡿⅣ⣲ⷧ⭷ࢆస〇ࡋࡓ࡜ࡇࢁࠊ㓟⣲㑏ඖ཯ᛂ࡟ᑐࡍࡿゐ፹άᛶࢆ᭷ࡋ࡚࠸ࡿࡇ࡜ࡀࢃ
࠿ࡗࡓࠋᩳධᑕ࡟ࡼࡿ 19 ⣲Ꮚ SSD ᳨ฟჾࢆ౑⏝ࡋࡓ⺯ගἲ XAFS ᐃ࡟ࡼࡾ㕲㏆ഐࡢᒁᡤᵓ㐀ࢆㄪ࡭ࡓ⤖ᯝࠊⷧ⭷ᙧᡂ ᗘࡀ㧗࠸ሙྜ࡟ࡣⷧ⭷୰࡟ 0 ౯ࡢ㕲ࡀจ㞟ࡋ࡚ࡃࡿࡶࡢࡢࠊ ࡘࡢ❅⣲ཎᏊࡀ㕲࡟ᖹ㠃≧࡟㓄఩ࡋ࡚ᙧᡂࡉࢀࡿᵓ㐀ࡀⅣ⣲ⷧ⭷୰࡟㻔Fe–N4 ᵓ㐀㻕ᙧᡂࡉࢀ࡚࠸ࡿࡇ࡜ࡀࢃ
࠿ࡗࡓࠋ࣮࣮࢟࣡ࢻ㸸 ⇞ᩱ㟁ụṇᴟゐ፹ࠊࣁ࢖ࣈࣜࢵࢻ≀⌮໬ᏛẼ┦ᡂ㛗ἲࠊάᛶⅬᵓ㐀ࠊXAFS⫼ᬒ࡜◊✲┠ⓗ㸸ᅛయ㧗ศᏊᆺ⇞ᩱ㟁ụࡢᮏ᱁ⓗᬑཬࡢᐇ⌧࡟㈉⊩ࡍࡿ࡜ᮇᚅࡉࢀࡿ㠀㈗㔠ᒓ⣔ṇᴟゐ፹ࡢ࠺ࡕࠊ
Fe–N4 ᵓ㐀ࢆゐ፹άᛶⅬ࡜ࡋ࡚⾲㠃࡟⤌ࡳ㎸ࡲࢀࡓⅣ⣲ᮦᩱࡀὀ┠ࡉࢀ࡚࠸ࡿࠋࡇࡢⅣ⣲ᮦᩱࡣ㕲ࣇࢱࣟࢩ࢔ࢽࣥ㻔FePcࠊFig.1㻕ࡸ㕲࣏ࣝࣇ࢕ࣜࣥ࡞࡝ࢆ⇕ฎ⌮ࡋ࡚స〇ࡍࡿࡢࡀ୍⯡ⓗ࡛࠶ࡿࠋࡋ࠿ࡋࠊゐ፹⾲㠃ୖ࡟άᛶ୰ᚰࡢ㕲ࡣከࡃ࡚ࡶ 0.36 atom %࡯࡝ࡋ࠿࡞ࡃࠊࡑࡢ⤖ᯝࠊゐ፹ᒙయ✚ᙜࡓࡾࡢάᛶࡀ᭱኱࡛ࡶⓑ㔠ゐ፹ࡢ 1/10 ࡜ࠊ࠸ࡲࡔ࡟ప࠸ࠋࡲࡓࠊ⪏ஂᛶࡶ༑ศ࡛ࡣ࡞࠸ࠋࡑࡢཎᅉ࡜ࡋ࡚ࠊ⇕ฎ⌮୰ࡢཎᩱࡢ᪼⳹࡟ࡼࡿᦆኻࠊ㕲ࡢจ㞟ࡀ⪃࠼ࡽࢀࡿࠋࡈࡃ᭱㏆࡟࡞ࡾࠊࢃࢀ
ࢃࢀࡣࠊୖグࡢၥ㢟ࢆゎỴྍ⬟࡞ࠊࣁ࢖ࣈࣜࢵࢻ≀⌮໬ᏛẼ┦ᡂ㛗㻔HPCVD㻕ἲ࡟╔┠ࡋࡓࠋHPCVDἲࡣ 2002 ᖺ࡟Ⓨ⾲ࡉࢀࡓẚ㍑ⓗ᪂ࡋ࠸ⷧ⭷ᡂ㛗ἲ࡛ [1]ࠊFe–N4 ᵓ㐀ࢆ᭷ࡍࡿⅣ⣲ᮦᩱࡢྜᡂ࡬ࡢᛂ⏝ࡣึࡵ࡚࡜࡞ࡿࠋ
HPCVD ἲ࡟࠾࠸࡚ࠊFePc ࢆཎᩱ࡜ࡋ࡚᪼⳹ࡉࡏࠊຍ⇕ࡋࡓᇶᯈୖ࡟ Fe–N4ᵓ㐀ࢆ᭷ࡍࡿⅣ⣲ᮦᩱࢆస〇ࡍࡿ࡜ࠊၥ㢟࡜࡞ࡗ࡚࠸ࡓ⇕ฎ⌮᫬࡟࠾ࡅࡿⅣ⣲ᮦᩱഃ࠿ࡽࡢ᪼⳹࡟ࡼࡿᦆኻࡣ㉳ࡇࡽࡎࠊ㏫࡟ᯒฟࡋ࡚࠸ࡃࡇ࡜࡟࡞ࡿࠋࡲࡓࠊᇶᯈୖ࡟ศᩓࡋ࡚ᯒฟࡉࡏࡿࡇ࡜࡟ࡼࡾ㕲ࡢจ㞟ࢆᢚ࠼ࡿຠᯝࡀᮇᚅ࡛ࡁࡿࠋࢃࢀࢃࢀࡣࠊึࡵ࡟ᐇ⏝ⓗ࡞ゐ፹ࢆస〇ࡍࡿ๓࡟ࠊ㧗㓄ྥᛶ⇕ศゎ㯮㖄㻔HOPG㻕ࡢ࣮࣋ࢧࣝ㠃ࢆᇶᯈ࡜ࡋ࡚ࣔࢹࣝゐ፹ࡢస〇ࢆ⾜࠺ࡇ࡜ࢆヨࡳࡓࠋࡑNNNFeNNNNNFig.1 Molecular structure of iron phthalocyanine.

ࡢ⤖ᯝࠊFe–N4 ᵓ㐀ࢆ᭷ࡍࡿⅣ⣲ᮦᩱࡢᢸᣢࡀ୙ྍ⬟࡛࠶ࡗࡓ HOPG ࣮࣋ࢧࣝ㠃ୖ࡟ࠊ⡆᫆ⓗ࡞
HPCVD ἲ࡟ࡼࡾࠊFePc ࢆཎᩱ࡟⏝࠸࡚ࠊ㓟⣲㑏ඖ཯ᛂ࡟ᑐࡍࡿάᛶࢆ᭷ࡍࡿⅣ⣲ⷧ⭷ࡢస〇࡟ึࡵ࡚ᡂຌࡋࡓࠋ௒ᅇࡢᐇ㦂࡛ࡣࠊHPCVD ἲ࡟ࡼࡿゐ፹స〇࡟㛵ࡍࡿᇶ♏ⓗ▱ぢࢆᚓࡿࡇ࡜ࢆ┠ⓗ࡜ࡋࠊࡇࡢⅣ⣲ⷧ⭷୰ࡢάᛶⅬᵓ㐀ࢆ XAFS ࡟ࡼࡾ᫂ࡽ࠿࡟ࡍࡿࡇ࡜ࡀ┠ᶆ࡛࠶ࡿࠋᐇ㦂㸸⡆᫆ⓗ࡞ HPCVD ἲ࡟ࡼࡾࠊHOPG ୖ࡬ࡢⅣ⣲ⷧ⭷ࡢస〇ࢆ 600, 700, 800, 900, 1000 ºC ࡛⾜ࡗࡓࠋⅣ⣲ⷧ⭷࡟ 3º ࡛ᨺᑕගࢆධᑕࡉࡏࠊ19 ⣲Ꮚ SSD ᳨ฟჾࢆ౑⏝ࡋࡓ Fe-K Ẇࡢ XAFS ࢆ⺯ගἲ࡟ࡼࡾ ᐃࢆ⾜ࡗࡓࠋᚓࡽࢀࡓ EXAFS ࢫ࣌ࢡࢺࣝࡢࣇ࣮࢚ࣜኚ᥮࡟ࡼࡾືᚄศᕸ㛵ᩘࢆồࡵࡓࠋ⤖ᯝ࠾ࡼࡧ⪃ᐹ㸸Ⅳ⣲ⷧ⭷ࡢືᚄศᕸ㛵ᩘࢆ Fig.2 ࡟♧ࡍࠋẚ㍑ࡢࡓࡵࠊ㏱㐣ἲ࡟ࡼࡾ ᐃࡋࡓ FePc ࡜㕲⟩ࡢືᚄศᕸ㛵ᩘࡶ♧ࡍࠋFePc ࡢືᚄศᕸ㛵ᩘ࡟࠾࠸࡚ࠊ1.6 Å ࡢ➨୍㏆᥋ࡢࣆ࣮ࢡࡣࠊ㕲࡟㓄఩ࡍࡿ 4ࡘࡢ❅⣲࡟㉳ᅉࡋࠊ2.7 Å ࡢ➨஧㏆᥋ࡢࣆ࣮ࢡࡣࠊ➨୍㏆᥋ཎᏊࡢ❅⣲࡟⤖ྜࡍࡿࣆ࣮ࣟࣝ⎔ෆࡢⅣ⣲࡜ࣆ࣮ࣟࣝ⎔ࢆᶫΏࡋࡍࡿ❅⣲࡟㉳ᅉࡍࡿࠋ
600 ºC ࡛స〇ࡋࡓⷧ⭷ࡢືᚄศᕸࡣࠊᙉᗘࡀࡸࡸᙅࡃࠊᖜᗈࡃ࡞ࡗ࡚࠸ࡿࡶࡢࡢࠊFePc ࡢືᚄศᕸ࡜㢮ఝࡋ࡚࠾ࡾࠊFePc ࡀࠊ࠾࠾ࡼࡑࡑࡢࡲࡲᯒฟࡋࠊFe–N4 ᵓ㐀ࡶಖᣢࡉࢀ࡚࠸ࡿ࡜ᛮࢃࢀ
ࡿࠋⷧ⭷స〇 ᗘࡢୖ᪼࡜࡜ࡶ࡟ࠊ㕲⟩ࡢࢫ࣌ࢡࢺࣝ࡟㢮ఝࡋࡓࢫ࣌ࢡࢺࣝࡀ⌧ࢀ࡚ࡃࡿࡇ࡜࠿
ࡽࠊFePc ࡀศゎࡋࠊ㕲ศࡀ Fe㻔0㻕࡜ࡋ࡚จ㞟ࡋ࡚࠸ࡿࡇ࡜ࡀ♧၀ࡉࢀࡓࠋࡋ࠿ࡋࠊFePc ࠾ࡼࡧ 600ºC ࡛స〇ࡋࡓⷧ⭷ࡢືᚄศᕸ࡜ࡢẚ㍑࠿ࡽࠊFe–N4 ᵓ㐀࡟㉳ᅉࡍࡿࣆ࣮ࢡࡶṧᏑࡋ࡚࠸ࡿ࡜⪃࠼ࡽࢀࠊࡇࡢࡇ࡜࠿ࡽ㒊ศⓗ࡟Ⅳ⣲ⷧ⭷ෆ࡟ Fe–N4 ᵓ㐀ࡀಖᣢࡉࢀ࡚࠸ࡿࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓࠋ

Fourier transformed amplitude(a.u.)⤖ㄽ㸸㕲ࣇࢱࣟࢩ࢔ࢽࣥࢆཎᩱ࡜ࡋ࡚ࠊHPCVD ἲ࡟ࡼࡾ HOPG ୖ࡟స〇ࡋࡓⅣ⣲ⷧ⭷୰࡟ྵࡲࢀࡿ㕲࿘ᅖࡢᒁᡤᵓ㐀ࡢศᯒ࡟ࠊᩳධᑕ࡟ࡼࡿ 19 ⣲Ꮚ SSD ᳨ฟჾࢆ౑⏝ࡋࡓ⺯ගἲ XAFS ᐃࡀ᭷ຠ࡛࠶ࡗࡓࠋศᯒࡢ⤖ᯝࠊ㕲࿘ᅖࡢᒁᡤᵓ㐀ࡣࠊⅣ⣲ⷧ⭷ࡢస〇 ᗘ࡟ࡼࡗ࡚␗࡞ࡿࡇ࡜ࡀࢃ࠿ࡗࡓࠋⷧ⭷ᙧᡂ ᗘࡀ㧗࠸ሙྜ࡟ࡣࠊ㕲ࣇࢱࣟࢩ࢔ࢽࣥࡀศゎࡋࠊⷧ⭷୰࡟ 0 ౯ࡢ㕲ࡢจ㞟ࡀぢࡽࢀࡿࡶࡢࡢࠊ࡝ࡢస〇 ᗘ࡟࠾࠸࡚ࡶ Fe–N4 ᵓ㐀ࡀಖᣢࡉࢀ࡚࠸ࡿࡇ࡜ࡀ᫂☜࡜࡞ࡗࡓࠋ

Fe foil (㽢1/4)
1000 ºC (㽢1/2)
900 ºC (㽢1/2)
800 ºC
700 ºC
600 ºC
FePc
012

3

4

5

6

Radial coordination/ÅFig.2 Pseudo-radial distribution functions calculated by Fourier transformation of extended X-ray
adsorption fine spectra at the Fe K-edge for carbon thin films formed at various heat-treatment
temperature, Fe phthalocyanine 㻔FePc㻕, and Fe foil.

௒ᚋࡢㄢ㢟㸸௒ᅇࡢㄢ㢟࡛ศᯒࡋࡓⅣ⣲ⷧ⭷ࡢస〇ἲࡣࠊ࠶ࡃࡲ࡛⡆᫆ⓗ࡞ HPCVD ἲ࡛࠶ࡗࡓࠋ௒ᚋࡣᇶᯈ࡜ཎᩱ ᗘࢆ⢭ᐦ࡟ไᚚࡍࡿ࡞࡝ࠊᮏ᱁ⓗ࡞ HPCVD ἲࢆ㛤ⓎࡋࠊFePc ࢆຠ⋡ⓗ࡟ᯒฟࡉࡏࠊࡉࡽ࡟ࠊFe ࡢจ㞟ࢆ㜵࠸࡛ Fe–N4 ᵓ㐀ࢆᴟຊಖᣢࡍࡿࡇ࡜ࡀㄢ㢟࡛࠶ࡿࠋཧ⪃ᩥ⊩㸸
[1] X. Zeng, A. V. Pogrebnyakov, A. Kotcharov, J. E. Jones, X. X. Xi, E. M. Lysczek, J. M. Redwing, S.
Xu, Q. Li, J. Lettieri, D. G. Schlom, W. Tian, X. Pan and Z.-K. Liu, Nat. Mater., 1, 35 㻔2002㻕.