http://support.spring8.or.jp/Report_JSR/PDF_JSR_31A/2019A1617.pdf

2019A1617BL14B2᭷ᶵ⤖ᬗࡢᵓ㐀ࢆ⥔ᣢࡋࡓ㔠ᒓྵ᭷Ⅳ⣲໬≀ࡢᒁᡤᵓ㐀ࡢゎ᫂
Analysis of the Local Structure in Metal-Incorporated CarbonaceousMaterials୸ᒣ ⣧ a, すཎ ὒ▱ b, ᒣᮏ 㞞⣡ b
Jun Maruyamaa, Hirotomo Nishiharab, Masanori Yamamotoba㻔ᆅ⊂㻕኱㜰⏘ᴗᢏ⾡◊✲ᡤ, b ᮾ໭኱Ꮫ㻌 ከඖ≀㉁⛉Ꮫ◊✲ᡤ
aOsaka Research Institute of Industrial Science and Technology, b Tohoku University, Institute ofMultidiciplinary Research for Advanced Materials ከᏍ㉁つ๎Ⅳ⣲ᮦᩱ[1]ࡢ᪂ᒎ㛤ࢆᅗࡿ࡭ࡃࠊከᵝ࡞ᵓ㐀ࢆ᭷ࡍࡿⅣ⣲ᮦᩱ࡞ࡽࡧ࡟ࡑࡢ๓㥑యࢆㄪ〇ࡋࠊࡑࡢᒁᡤᵓ㐀ࢆ X ⥺྾཰ᚤ⣽ᵓ㐀ゎᯒ࡟ࡼࡾホ౯ࡋࡓࠋࡑࡢ⤖ᯝࠊ᪂ࡓ࡟᳨ウࡋࡓᮦᩱ࡟࠾࠸࡚ࠊฟⓎཎᩱࡢ᭷ᶵศᏊෆ㒊ࡢ㔠ᒓ㓄఩⎔ቃࢆሀᣢࡋࡓⅣ⣲ᮦᩱࡀᚓࡽࢀࡓࡇ࡜ࢆ᫂ࡽ࠿࡟ࡋࡓࠋᚓࡽࢀࡓศᏊㄽⓗ࡞▱ぢࢆࡶ࡜࡟ࠊ௒ᚋィ⟬໬Ꮫⓗ࡞⿬௜ࡅࡀྍ⬟࡟࡞ࡿ࡜࡜ࡶ࡟ࠊࡼࡾྜ⌮ⓗ࡞ศᏊタィࡀྍ⬟࡟࡞ࡿ࡜ᮇᚅࡉࢀࡿࠋ࣮࣮࢟࣡ࢻ㸸 ᭷ᶵ⤖ᬗࠊ࣏ࣝࣇ࢕ࣜࣥࠊ࣮࢝࣎ࣥ࢔ࣟ࢖⫼ᬒ࡜◊✲┠ⓗ㸸Ⅳ⣲ᮦᩱࡣே㢮࡟Ḟ࠿ࡏ࡞࠸ᐇ⏝ᮦᩱ࡛࠶ࡾࠊ྾╔ᮦᩱࡸゐ፹ࡢᑟ㟁ຓ๣ࠊࢱ࢖ࣖࡢᵓ㐀⥔ᣢࡢࡓࡵࡢῧຍ๣࡜ࡋ࡚ᖜᗈࡃ฼⏝ࡉࢀ࡚࠸ࡿࠋࡋ࠿ࡋ࡞ࡀࡽࡑࡢᵓ㐀ࡢヲ⣽ࡣ⌮ゎࡉࢀ࡚࠾ࡽࡎࠊࠕࡼࡃศ࠿ࡽ࡞࠸ࡅ࡝ࡶ౑࠼ࡿࠖ࡜࠸࠺ᇦࢆฟ࡚࠸࡞࠸ࠋࡇࢀ࡟ᑐࡋࠊ➹⪅ࡽࡣࠊ୕㔜⤖ྜ࡞࡝ࡢ㐺ษ࡞཯ᛂᛶ⨨᥮ᇶࢆᑟධࡋࡓศᏊ⤖ᬗࢆ⇕ฎ⌮࠾ࡼࡧⅣ⣲໬ࡍࡿࡇ࡜࡟ࡼࡾࠊࢼࣀ࡛ࣞ࣋ࣝᵓ㐀ไᚚࡉࢀࡓከᏍᛶつ๎ᛶᮦᩱࡢㄪ〇࡟ᡂຌࡋ࡚࠸ࡿ[1]ࠋࡇࡢࠕ࣮࢝࣎ࣥ࢔ࣟ࢖ࠖ࡟࠾࠸࡚ࡣࢽࢵࢣࣝཎᏊࡀ࣏ࣝࣇ࢕ࣜࣥ஧㔞యศᏊ⏤᮶ࡢࢼࣀ✵㛫࡟➼㛫㝸࡟つ๎ṇࡋࡃ㓄⨨ࡉࢀ࡚࠾ࡾࠊࡇࢀࢆ㟁Ẽ໬Ꮫゐ፹࡜ࡋ࡚⏝࠸ࡿࡇ࡜࡛ࠊ஧㓟໬Ⅳ⣲㞺ᅖẼୗ࡛ࡢ KHCO3 Ỉ⁐ᾮࢆ㟁ゎᾮ࡜ࡋࡓ୕ᴟᘧࢭࣝ࡟࠾࠸࡚ࠊí0.8 V vs ྍ㏫Ỉ⣲㟁ᴟ䠄RHE䠅ࡢ㟁ᅽ༳ຍ࡟ࡼࡾ஧㓟໬Ⅳ⣲ࢆ 90%๓ᚋࡢࣇ࢓ࣛࢹ࣮ຠ⋡୍࡛㓟໬Ⅳ⣲࡟ኚ᥮࡛ࡁࡿࡇ࡜ࢆぢฟࡋ࡚࠸ࡿࠋࡲࡓࠊ600ºC ௨ୖ࡛ࡢ⇕ฎ⌮ᚋࡶࢽࢵࢣࣝ࡬ࡢᖹ㠃❅⣲ᅄ㓄఩ᵓ㐀ࡀሀᣢࡉࢀ࡚࠸ࡿࡇ࡜ࢆ SPring-8 ࡟࠾ࡅࡿ X ⥺྾཰ᚤ⣽ᵓ㐀ゎᯒ࡟ࡼࡾ᫂ࡽ࠿࡟ࡋ࡚࠸ࡿࠋ⌧≧࡛ࡣࠊᵓ㐀ไᚚࡉࢀࡓࠕ࣮࢝࣎ࣥ࢔ࣟ࢖ࠖࡢཎᩱ࡜ࡋ࡚ࡣࠊ୕㔜⤖ྜ࡛ᶫΏࡋࡉࢀࡓࢽࢵࢣ࣏ࣝࣝࣇ࢕ࣜࣥ஧㔞యศᏊࡔࡅ࡛࠶ࡿ㸦ᅗ 1㸧ࡀࠊࡑࡢࡼ࠺࡞つ๎Ⅳ⣲ᮦᩱࡢᬑ㐢ⓗ࡞Ⅳ⣲ᮦᩱࡢタィ࣭ྜᡂᣦ㔪ࢆᚓࡿ࡜࡜ࡶ࡟ࠊᇶ♏Ꮫ⌮ᵓ⠏ࢆ┠ᣦࡍࡇ࡜ࢆ┠ⓗ࡜ࡋ࡚ࠊᮏ ᐃ࡛ࡣࠊ㔠ᒓ✀ࢆ Ni ࡟᭰࠼࡚ Fe ࡜ࡋࠊ஧㔞య࡛ࡣ࡞ࡃࠊ༢㔞యࡢศᏊ๓㥑య࠿ࡽᚓࡓⅣ⣲ᮦᩱ࡞ࡽࡧ࡟ࡑࡢ๓㥑య࡟࠾ࡅࡿ㔠ᒓࡢᒁᡤᵓ㐀ࢆ XAFS ࡟ࡼࡗ࡚ศᯒࡋࡓࠋᅗ 1㸬 ࣮࢝࣎ࣥ࢔ࣟ࢖ࡢㄪ〇ࢫ࣮࣒࢟ࠋ300ºC ௜㏆࡛࢔ࢭࢳࣞࣥ㒊఩ࡀ⇕㔜ྜࡋࠊࡉࡽ࡟㧗࡛Ⅳ⣲໬ࡍࡿ࡜ Ni-N4 㓄఩ᵓ㐀ࡀ㦵᱁ෆ࡟⥔ᣢࡉࢀࡓつ๎ᛶⅣ⣲໬≀ࡀᚓࡽࢀࡿࠋ䠉㻝㻝䠉ᐇ㦂㸸㕲࣏ࣝࣇ࢕ࣜࣥศᏊ䠄m-FePࠊᅗ 2䠅ࠊ୙άᛶ㞺ᅖẼୗ࡟࠾࠸࡚ 600ºC ࡛⇕ฎ⌮ࡋ࡚ᚓࡽࢀࡓⅣ⣲
ᮦᩱࠊ270ºCࠊ450ºC ࡛⇕ฎ⌮ࡋ࡚ᚓࡽࢀࡓⅣ⣲ᮦᩱ๓㥑యࠊィ 4 ヨᩱ࡟ࡘ࠸࡚ࠊXRDࠊ❅⣲྾⬺╔ ᐃࠊ㧗ゅᩓ஘⎔≧ᬯど㔝㉮ᰝ㏱㐣㢧ᚤ㙾ἲ䠄HAADF-STEM䠅࡛ᮦᩱホ౯ࢆ⾜ࡗࡓୖ࡛ࠊXAFS
ᐃࢆ⾜ࡗࡓࠋXAFS ᐃࡢᶆ‽ヨᩱ࡜ࡋ࡚ࠊ0 ౯㕲⟩࠾ࡼࡧ 3 ౯㓟໬㕲䠄Fe2O3䠅ࢆ⏝࠸ࡓࠋヨᩱ⢊ᮎࢆ❅໬࣍࢘⣲⢊ᮎ࡜ΰྜࡋࡓࡢࡕ┤ᚄ 5 mm ࡢ࣌ࣞࢵࢺ࡟ᙧᡂࡋ㏱㐣 XAFS ᐃ࡟⏝࠸ࡓࠋ
㏱㐣ἲ XAFS ᐃ࡟࡚ࠊFe-K ྾཰➃ࡢศᯒࢆ⾜ࡗࡓࠋᇶᮏⓗ࡟ヨᩱࡣᐊ ࠊ኱Ẽ୰࡛ ᐃࡋࡓࠋࡲࡓࠊREX 2000 ࢆ⏝࠸࡚ᚓࡽࢀࡓࢹ࣮ࢱࡢゎᯒࢆ⾜ࡗࡓࠋ
ᅗ 2. Fe ྵ᭷つ๎Ⅳ⣲໬≀ࡢ๓㥑య࡛࠶ࡿ Fe ࣏ࣝࣇ࢕ࣜࣥ㻔m-FeP㻕ࠋ⇕㔜㔞ศᯒ-㉁㔞ศᯒ࡟ࡼࡾࠊ300ºC ๓ᚋ࡛࢔ࢭࢳࣞࣥ㒊఩ࡀ⇕㔜ྜࡋࠊࡲࡓ 300ºC ௨ୖ࡛ሷ໬≀࢖࢜ࣥࡀ㞳⬺ࠊ500ºC ௨ୖ࡛ࣇ࢙ࢽࣝᇶࡀ㞳⬺ࡍࡿࡇ࡜ࡀศ࠿ࡗ࡚࠸ࡿࠋ⤖ᯝ࠾ࡼࡧ⪃ᐹ㸸X ⥺ᅇᢡ䠄XRD䠅ࡸ㏱㐣ᆺ㟁Ꮚ㢧ᚤ㙾䠄TEM䠅ほᐹ࠿ࡽࠊm-FeP ࡣࠊ600ºC ࡛ࡢ⇕ฎ⌮ᚋࡶつ๎ᵓ㐀ࡀಖᣢࡉࢀࡓⅣ⣲ᮦᩱࢆ୚࠼ࡿࡇ࡜ࡀࢃ࠿ࡾࠊ⇕㔜ྜ࣭Ⅳ⣲໬ࡢࡓࡵ࡟㐺ษ࡞⨨᥮ᇶࢆ᭷ࡋ࡚
࠸ࡿࡇ࡜ࢆ☜ㄆࡋࡓࠋࡲࡓࠊm-FeP ࡢⅣ⣲໬ᣲື࡟ࡘ࠸࡚ࡣࠊ୙άᛶ㞺ᅖẼୗ࡛ࡢ⇕㔜㔞ศᯒí♧ᕪ㉮ᰝ⇕㔞ィí㉁㔞ศᯒࢆᐊ ࠿ࡽ 800ºC ࡲ࡛㐃⥆ⓗ࡟⾜࠺ࡇ࡜࡛ḟࡢࡼ࠺࡞ศᏊㄽⓗ᝟ሗࢆᚓ࡚࠸ࡿࠋࡍ࡞ࢃࡕࠊࡲࡎ 300ºC ௜㏆࡛୕㔜⤖ྜ㒊఩ࡢ⇕㔜ྜࡀ㐍⾜ࡍࡿࠋຍ࠼࡚ࠊ㕲࣏ࣝࣇ࢕ࣜࣥ࡟㍈㓄఩ࡋࡓሷ໬≀࢖࢜ࣥࡀ 300ºC ௨ୖ࡛ሷ໬Ỉ⣲䠄m/z = 36, 38䠅࡜ࡋ࡚㞳⬺ࡍࡿࠋḟ࡟ࠊ
500ºC ௜㏆࠿ࡽࠊࣇ࢙ࢽࣝ㒊఩ࡀ࣋ࣥࢮࣥ䠄m/z = 78䠅ࡸࢺ࢚ࣝࣥ䠄m/z = 92䠅࡜ࡋ࡚㞳⬺ࡍࡿࠋࡇࡢࡼ࠺࡞Ⅳ⣲໬ᣲືࢆ♧ࡍᮦᩱ⩌࡟ࡘ࠸࡚ࠊḟ࡟ XAFS ᐃࢆ⾜ࡗࡓࠋᅗ 3 ࡟ m-FeP ࠾ࡼࡧ 270ºCࠊ450ºCࠊ600ºC ࡛⇕ฎ⌮ࡋࡓヨᩱࡢ XAFS ࡢ⤖ᯝࢆ♧ࡍࠋྛ⇕ฎ⌮ᗘ࡟࠾ࡅࡿ m-FeP ࡢ XANES ࡣ Fe ⟩ࡸ㓟໬㕲࡜ࡣ␗࡞ࡿᙧ≧ࢆ୚࠼࡚࠾ࡾࠊFe ୰ᚰࡢ㓟໬ᩘࡣ࠸ࡎࢀࡶ 3 ౯࡜⪃࠼ࡽࢀࡿࠋࡲࡓࠊ࠸ࡎࢀࡢヨᩱࡶ 7110 eV ௜㏆࡟ࣉ࢚ࣞࢵࢪࣆ࣮ࢡࢆ୚࠼࡚࠾ࡾࠊ⇕ฎ⌮࡟ࡼࡿ m-FeP ୰ࡢ㕲ཎᏊࡢ㟁Ꮚ≧ែኚ໬ࡣ㝈ᐃⓗ࡛࠶ࡿ࡜⪃࠼ࡽࢀࡿࠋ௚᪉ࠊEXAFS࠿ࡽᚓࡽࢀࡓືᚄᵓ㐀㛵ᩘ࠿ࡽࠊ୰ᚰ㕲ཎᏊࡢ㓄఩≧ែࡣ⇕ฎ⌮ ᗘ࡟ࡼࡽࡎᖹ㠃❅⣲ᅄ㓄఩ᵓ㐀ࢆ⥔ᣢࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡗࡓࠋ⇕ศゎ⏕ᡂ≀࡜ࡋ࡚ࣆ࣮ࣟࣝ䠄m/z = 67䠅ࡀ᳨ฟࡉࢀ࡚࡞࠸ࡇ࡜ࡶ㚷ࡳࡿ࡜ࠊྵ㕲ඹᙺȧ⣔㦵᱁㸦࣏ࣝࣇ࢕ࣜࣥ㕲㘒య㸧⮬యࡀ⇕ฎ⌮ᚋࡶ⥔ᣢࡉࢀ࡚࠸ࡿ࡜⪃࠼ࡽࢀࡿࠋ䠉㻝㻞䠉

ᅗ 3. Fe ྵ᭷つ๎Ⅳ⣲໬≀ࡢ๓㥑య࡛࠶ࡿ Fe ࣏ࣝࣇ࢕ࣜࣥ㻔m-FeP㻕ࡢྛ⇕㔜ྜ࣭Ⅳ⣲໬ฎ⌮ᚋࡢXAFSࠋ
㸦ᕥ㸧XANES㸦ྑ㸧Fe K ➃ EXAFS ࠿ࡽᚓࡽࢀࡓᨃືᚄᵓ㐀㛵ᩘࠋᶆ‽ヨᩱ㸦Fe ⟩ཬࡧ Fe2O3㸧ࡢ⤖ᯝ࡟ࡘ࠸࡚ࡶేࡏ࡚♧ࡍࠋᮏ◊✲࡟ࡼࡾࠊከᏍᛶࡢᵓ㐀つ๎ᛶ࣮࢝࣎ࣥ࢔ࣟ࢖ㄪ〇࡟ྥࡅࡓ᳨ウࡀ኱ࡁࡃ๓㐍ࡋࡓࠋ≉࡟ࠊ⨨᥮ᇶ➼ࡢศᏊᵓ㐀ࡀⅣ⣲໬ᣲື࡟୚࠼ࡿᙳ㡪࡟ࡘ࠸࡚ࡢ⌮ゎࡀ῝ࡲࡗࡓࠋࡲࡓࠊ㔠ᒓ✀ࢆ Ni ࡟᭰࠼࡚ Fe ࡜ࡋࡓሙྜ࡛ࡶࠊᵓ㐀つ๎ᛶࡢⓎ⌧࡜࡜ࡶ࡟ᖹ㠃❅⣲ᅄ㓄఩ᵓ㐀ࡀ⥔ᣢࡉࢀࡿࡇ࡜ࢆぢฟࡋࡓࠋᚑ๓ࠊ㠀ᖖ࡟㧗άᛶ࡞㟁Ẽ໬Ꮫゐ፹ࡀሗ࿌ࡉࢀ࡚࠸ࡿࡀ[2,3]ࠊࡑࡢᒁᡤⓗ࡞ᵓ㐀ࡣ୙࡛᫂࠶ࡾࠊࢼࣀ࡛ࣞ࣋ࣝࡢᵓ㐀íάᛶ┦㛵ࡢྲྀᚓࡸィ⟬໬Ꮫⓗ࡞࢔ࣉ࣮ࣟࢳࡀᅔ㞴࡛࠶ࡗࡓࠋࡇࢀ࡟ᑐࡋࠊᮏ◊✲࡛ࡣ᭷ᶵ⤖ᬗࡢᵓ㐀ࢆ⥔ᣢࡋࡓ㔠ᒓྵ᭷Ⅳ⣲໬≀ࡢᒁᡤᵓ㐀ࡀゎ࡛᫂ࡁࡓࡇ࡜࠿ࡽࠊ௒ᚋࠊ⣔⤫ⓗ࡟⨨᥮ᇶࢆኚ໬ࡉࡏࡓሙྜࡢ⇕ฎ⌮ᚋࡢつ๎ᛶ࣭ศᏊᵓ㐀ኚ໬࡟ຍ࠼࡚ィ⟬໬Ꮫⓗ࡞ゐ፹άᛶࡢ⿬௜ࡅ➼ࢆ᳨ウࡍࡿࡇ࡜࡛ࠊࡼࡾᬑ㐢ⓗ࡞Ⅳ⣲ᮦᩱࡢタィ࣭ྜᡂᣦ㔪ࢆᚓࡿࡓࡵࡢ
つ๎Ⅳ⣲ᮦᩱࡢᇶ♏Ꮫ⌮ࡀᵓ⠏ྍ⬟࡟࡞ࡿ࡜⪃࠼ࡿࠋཧ⪃ᩥ⊩㸸
[1] Hirotomo Nishihara, Tetsuya Hirota, Kenta Matsuura, Mao Ohwada, Norihisa Hoshino, Tomoyuki
Akutagawa, Takeshi Higuchi, Hiroshi Jinnai, Yoshitaka Koseki, Hitoshi Kasai, Yoshiaki Matsuo, JunMaruyama, Yuichiro Hayasaka, Hisashi Konaka, Yasuhiro Yamada, Shingi Yamaguchi, KazuhideKamiya, Takuya Kamimura, Hirofumi Nobukuni, Fumito Tani, Nat. Commun., 8, 109䠄2017䠅.
[2] Jun Gu, Chia-Shuo Hsu, Lichen Bai, Hao Ming Chen, Xile Hu, Science, 364, 1091í1094䠄2019䠅.
[3] Lili Han, Xijun Liu, Jinping Chen, Ruoqian Lin, Haoxuan Liu, Fang Lü, Seongmin Bak Zhixiu Liang,Shunzheng Zhao, Eli Stavitski, Jun Luo, Radoslav R. Adzic, Huolin L. Xin, Angew. Chem. Int. Ed., 58,2321í2325䠄2019䠅.

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