福岡工業大学学術機関リポジトリ

(1)

福岡工業大学学術機関リポジトリ

Development of Highly Catalytically Active Bimetallic Nanoparticle Formation in Porous SiO2 by Supercritical Fluid-assisted

Immobilization

言語: jpn 出版者:

公開日: 2021-01-07 キーワード (Ja):

キーワード (En):

作成者: 松山, 清メールアドレス:

所属:

メタデータ

http://hdl.handle.net/11478/00001580

URL

(2)

㉸⮫⏺ྵᾐἲࢆ⏝࠸ࡓከᏍ㉁ࢩࣜ࢝୰࡛ࡢ 㧗άᛶࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢ㛤Ⓨ

ᯇᒣ Ύ㸦ᕤᏛ㒊⏕࿨⎔ቃ໬Ꮫ⛉㸧

Development of Highly Catalytically Active Bimetallic Nanoparticle Formation in Porous SiO

2

by Supercritical Fluid-assisted Immobilization

MATSUYAMA Kiyoshi㸦Department of Life, Environment and Applied Chemistry, Faculty of Engineering㸧

Abstract

The supercritical carbon dioxide (scCO2) for the impregnation and deposition of metal nanoparticles are effective for uniformly decorating and impregnating porous materials. In this work, Cu-Ru bimetallic nanoparticles were successfully immobilized in the mesopores of hierarchical porous SiO2 by using scCO2-acetone solution. STEM-EDX mapping measurements demonstrated that Cu and Ru atoms were homogeneously scattered in mesopores of hierarchical porous SiO2. The resulting Cu-Ru@SiO2 exhibited high activity. The catalytic activity of bimetallic Cu-Ru@SiO2 for CO oxidation was higher than that of monometallic Cu@SiO2, Ru@SiO2 and Rh@SiO2.

Keywords㸸Bimetallic Nanoparticles, Immobilization, Supercritical CO2, CO Oxidation

1. ⥴ゝ

ᡃࡀᅜࡢ⏘ᴗ➇த࡟୙ྍḞ࡛࠶ࡿᕼᑡඖ⣲(ࣞ࢔࢔࣮ࢫ࣭

ࣞ࢔࣓ࢱࣝ➼)ࡣࠊ㈨※ࢼࢩࣙࢼࣜࢬ࣒ࡸ㈨※᥇᥀࡟࡜ࡶ࡞

࠺⎔ቃ㈇Ⲵ࡞࡝ࡢせᅉ࡟ࡼࡾࠊ㛗ᮇⓗ࡞Ᏻᐃ౪⤥ࡢⅬ࡛ၥ 㢟࡜ࡉࢀ࡚ࡁࡓࠋࡇࡢࡓࡵࠊᕼᑡඖ⣲ࡢᏳᐃ౪⤥ࡀồࡵࡽ

ࢀࠊྠ᫬࡟ᕼᑡඖ⣲ࡢ฼⏝㔞పῶࠊࣜࢧ࢖ࢡࣝᢏ⾡ࡸ௦᭰ᮦ

ᩱࡢ㛤Ⓨࡀᛴົ࡜ࡉࢀ࡚࠸ࡿࠋ≉࡟⮬ື㌴⏝ࡢ᤼࢞ࢫί໬

ゐ፹࡞࡝࡟฼⏝ࡉࢀࡿࣟࢪ࣒࢘㸦Rh㸧➼ࡢᕼᑡඖ⣲࡛࠶ࡿⓑ

㔠᪘㔠ᒓࡣࠊ㏆ᖺࡢ࢔ࢪ࢔ᆅᇦ࡟࠾ࡅࡿ⮬ື㌴ࡢᬑཬ࡟࡜

ࡶ࡞࠺᤼࢞ࢫί໬ゐ፹ࡢ㟂せࡢ㧗ࡲࡾࡢᙳ㡪ࢆཷࡅ࡚ࠊࡑ ࡢ౪⤥ࡀ㠀ᖖ࡟୙Ᏻᐃ࡜࡞ࡗ࡚࠸ࡿ^(1)-(3)ࠋ㏆ᖺࠊࡇࡢࡼ࠺࡞

ᕼᑡඖ⣲ࡢᯤῬၥ㢟ࢆゎỴࡍࡿࡓࡵࡢᡭἲ࡜ࡋ࡚ࠊࣂࣝࢡ

≧ែ࡛ࡣ┦ศ㞳ࡋ࡚ΰࡊࡾྜࢃ࡞࠸㔠ᒓࡢ⤌ࡳྜࢃࡏࢆࢼ

ࣀ࡛ࣞ࣋ࣝᅛ⁐໬ࡋࠊ᪂つࢼࣀྜ㔠ゐ፹㸦ࣂ࢖࣓ࢱࣝࢼࣀ⢏

Ꮚゐ፹➼㸧ࢆྜᡂࡍࡿඖ⣲㛫⼥ྜᢏ⾡ࡀ᳨ウࡉࢀ࡚࠸ࡿ^(4)-

(6)ࠋᵝࠎ࡞ᡭἲ࡟ࡼࡿࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢ㛤Ⓨ࡜ࡑࡢ ᕤᴗⓗつᶍ࡛ࡢᐇ⏝໬ࡀᮇᚅࡉࢀࠊࣝࢸࢽ࣒࢘Ru㸦ཎᏊ␒

ྕ44; 990 ෇/g㸧࠾ࡼࡧࣃࣛࢪ࣒࢘Pd㸦ཎᏊ␒ྕ46; 7,000

෇/g㸧࠿ࡽࠊRh㸦ཎᏊ␒ྕ45; 30,000 ෇/g㸧ࡼࡾࡶඃࢀࡓ୍

㓟໬Ⅳ⣲㸦CO㸧㓟໬ࡢゐ፹≉ᛶࢆ᭷ࡍࡿPd-Ru⣔ࣂ࢖࣓ࢱ

ࣝࢼࣀ⢏Ꮚゐ፹ࡀྜᡂࡉࢀ࡚࠸ࡿ⁽⁷⁾㸦ᮏሗ࡟グ㍕ࡋࡓRu, Pd, Rh࠾ࡼࡧCuࡢ༢౯ࡣࠊ2020ᖺ7᭶ࡢ┦ሙ౯᱁ᖹᆒ್㸧ࠋྜ

ᡂࡉࢀࡓPd-Ru⣔ࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡣࠊPd࡜Ruࡢ

༢㔠ᒓࡢࡳ࡛ྜᡂࡉࢀࡓࢼࣀ⢏Ꮚゐ፹ࡼࡾࡶάᛶࡢྥୖࡀ

☜ㄆࡉࢀ࡚࠸ࡿ⁽⁸⁾ࠋPd-Ru⣔ࣂ࢖࣓ࢱࣝࢼࣀ⢏ᏊࡣࠊCO㓟

໬཯ᛂ࡟࠾࠸࡚Rhࢆୖᅇࡿゐ፹άᛶࢆ᭷ࡍࡿࠋ㏆ᖺ࡛ࡣᏳ ౯࡛࠶ࡾ࡞ࡀࡽ㧗࠸㓟⣲ぶ࿴ᛶࢆ᭷ࡍࡿ㖡Cu㸦ཎᏊ␒ྕ29;

0.7 ෇/g㸧࡜୍㓟໬Ⅳ⣲྾╔ᛶࢆ᭷ࡍࡿ Ru࡟╔┠ࡋ࡚ࠊࡼ

ࡾపࢥࢫࢺࡢゐ፹స〇ࡀ⾜ࢃࢀ࡚࠾ࡾࠊCu࡜Ruࡢࢼࣀ⢏

Ꮚ」ྜ໬࡟ࡼࡿCO㓟໬άᛶࡢྥୖࡀሗ࿌ࡉࢀ࡚࠸ࡿ⁽⁹⁾ࠋ

୍᪉ࠊ㉸⮫⏺ὶయࡣࠊᅗ1࡟♧ࡍࡼ࠺࡟⮫⏺ ᗘTc࠾ࡼ

ࡧ⮫⏺ᅽຊpcࢆ㉸࠼ࡓ㠀จ⦰ᛶ㧗ᐦᗘὶయ࡛࠶ࡿࠋ㉸⮫⏺

ὶయࡣᚑ᮶ࡢ⁐፹࡜ࡣ␗࡞ࡾࠊ⾲ 1 ࡟♧ࡍࡼ࠺࡟ࡑࡢᐦᗘ

ࢆ⌮᝿Ẽయ࡟㏆࠸ᕼⷧ࡞≧ែ࠿ࡽᾮయ࡟┦ᙜࡍࡿ㧗ᐦᗘ࡞

≧ែࡲ࡛㐃⥆ⓗ࡟ኚ໬ࡉࡏࡿࡇ࡜ࡀྍ⬟࡛࠶ࡾࠊ ᗘ࣭ᅽຊ

ࢆ᧯సኚᩘ࡜ࡍࡿࡇ࡜࡟ࡼࡾ⁐ゎ≉ᛶ➼ࡢㅖ≀ᛶࡢ኱ᖜ࡞

ไᚚࡀྍ⬟࡜࡞ࡿࠋࡉࡽ࡟ࠊప⢓ᗘ࠿ࡘ㧗ᣑᩓᛶ࡛࠶ࡾᾮయ

࡜Ẽయࡢ฼Ⅼࢆවࡡഛ࠼࡚࠾ࡾࠊ᪂つⓗ࡞⁐፹࡜ࡋ࡚㏆ᖺ ὀ┠ࢆᾎࡧ࡚࠸ࡿࠋࡇࡢࡼ࠺࡞㉸⮫⏺ὶయࡢඃࢀࡓ⁐፹≉

ᛶࢆ฼⏝ࡍࡿࡇ࡜࡟ࡼࡾࠊࢥ࣮ࣄ࣮㇋ࡢ⬺࢝ࣇ࢙࢖ࣥࠊ㤶ᩱ

ᢳฟ࡞࡝ࠊᾮయ⁐፹࡛ࡣཎ⌮ⓗࠊᢏ⾡ⓗ࡟ᅔ㞴࡜ࡉࢀ࡚ࡁࡓ 㧗ᗘศ㞳ࣉࣟࢭࢫࡀࡍ࡛࡟ᕤᴗつᶍ࡛ᐇ⏝໬ࡉࢀࠊࡉࡽ࡟

ᵝࠎ࡞᪉㠃࡬ࡢᛂ⏝ࡀᮇᚅࡉࢀ࡚࠸ࡿ⁽¹⁰⁾ࠋ

㉸⮫⏺ὶయࢆ⏝࠸ࡓྵᾐᢏ⾡ࡣࠊୖ㏙ࡋࡓ≉᭷ࡢ㧗࠸ᣑ ᩓᛶ࣭ᾐ㏱ᛶ࠿ࡽࠊከᏍ㉁ᮦᩱࡢᩘnm⛬ᗘࡢᚤ⣽⣽Ꮝ࡬ࡢ ࢼࣀ⢏Ꮚࡢྵᾐ࣭ᅛᐃ໬᪉ἲ࡜ࡋ࡚ࡶ㐺ࡋ࡚࠾ࡾࠊࣂ࢖࣓ࢱ

ࣝࢼࣀ⢏Ꮚゐ፹ࡢゐ፹ᢸయ࡛࠶ࡿከᏍ㉁ࢩࣜ࢝㸦SiO2㸧࡬ࡢ ᅛᐃ໬࡟ᴟࡵ࡚᭷ຠ࡛࠶ࡿࡇ࡜ࡀᮇᚅ࡛ࡁࡿ^(11,12)ࠋࡇࡇ࡛ࠊ ᅗ 2 ࡟ᮏ◊✲ࡢ᧯సᴫせ࡟ࡘ࠸࡚ᴫ␎ᅗࢆ♧ࡍࠋ୍⯡࡟ࠊ

Pd-Ru⣔ࡸCu-Ru ⣔ࡢΰྜ≀⣔࡟࠾࠸࡚ࠊ┦ศ㞳࡟ࡼࡾᅛ

⁐యࢆᙧᡂࡍࡿࡇ࡜ࡣᅔ㞴࡛࠶ࡿ^(13,14)ࠋࡋ࠿ࡋ࡞ࡀࡽࠊᮏ◊

(3)

ᯇᒣ Ύ

✲࡛ࡣࠊ㉸⮫⏺ὶయࢆ⏝࠸࡚ࣂ࢖࣓ࢱࣝ๓㥑యࢆከᏍ㉁య ࡢ⣽Ꮝ࡟㛢ࡌ㎸ࡵࡿࡇ࡜࡟ࡼࡾ┦ศ㞳ࢆᢚไࡋࠊࢼࣀࣞ࣋

࡛ࣝ」ྜ໬ࡉࢀࡓPd-Ru⣔ࡸCu-Ru⣔ࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚ ࡢྜᡂࢆヨࡳࡓࠋᮏ◊✲࡛ࡣ CO2ࢆ౑⏝ࡋࡓ㉸⮫⏺ὶయྵ

ᾐἲࢆ⏝࠸ࠊࢼࣀ࡛ࣞ࣋ࣝࡢ஧✀㢮ࡢ㔠ᒓࢼࣀ⢏Ꮚࡢඖ⣲

㛫⼥ྜࡢ཯ᛂሙ࡜ࡋ࡚ゐ፹ᢸయ࡛࠶ࡿከᏍ㉁SiO2ࡢ⣽Ꮝࢆ

฼⏝ࡍࡿ^(15,16)ࠋከᏍ㉁SiO2࡟ࡣࠊゐ፹ᢸయ࡜ࡋ࡚ࡑࡢᕤᴗ

ⓗ฼⏝ࡀᮇᚅ࡛ࡁࠊ࣑ࢡࣟࣥࢫࢣ࣮ࣝࡢ㈏㏻Ꮝ࡜ࡑࡢ㦵᱁ ෆ࡟ࡣࢼࣀࢫࢣ࣮ࣝࡢ⣽Ꮝ࠿ࡽ࠿ᵓᡂࡉࢀࡿ஧ẁ㝵⣽Ꮝ SiO2ࢆ⏝࠸ࡓ^(17-19)ࠋ

⾲㸯 Ẽయࠊ㉸⮫⏺ὶయࠊᾮయࡢ≀ᛶ Table 1. Properties of gas, supercritical fluid and liquid.

≀ᛶ Ẽయ ㉸⮫⏺ὶయ ᾮయ

ᐦᗘ

[kg㺃m^-3] 0.6㹼2 300㹼900 700㹼1600 ᣑᩓಀᩘ

[10^-9m²㺃s^-1] 1000㹼4000 20㹼700 0.2㹼2

⢓ᗘ

[10^-5Pa㺃s] 1㹼3 1㹼9 200㹼300

ᅗ1 ⣧≀㉁ࡢ≧ែᅗ࡜㉸⮫⏺ὶయ

Fig. 1. Phase diagram of pure substance and supercritical fluid.

ᅗ2 ᮏ◊✲࡛ᥦ᱌ࡍࡿࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢྜᡂἲ Fig. 2. Principle of the formation of bimetallic nanoparticle

catalysis.

ࡲࡓࠊCuࡢ㓟⣲ぶ࿴ᛶ࡜RuࡢCO྾╔ᛶ࡟╔┠ࡋࠊRh ௨ୖࡢゐ፹άᛶࢆ᭷ࡋ࡞ࡀࡽࡶࠊCu࡜Ruࡢ஧✀㢮ࡢ㔠ᒓ

࠿ࡽᵓᡂࡉࢀࡿCu-Ru⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚࡀᅛᐃ໬ࡉ

ࢀࡓከᏍ㉁SiO2࡛࠶ࡿࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢస〇ࢆヨ

ࡳࡓࠋ

2. ᐇ㦂᪉ἲ

2.1ࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚࡢྜᡂ ゐ፹ᢸయ࡟ࡣࠊ㸦ᰴ㸧ࢹ࢕࣮

ࣆ࣮࢚ࢫ〇ࡢ஧ẁ㝵⣽ᏍSiO2 (DualPore SiO2; DPS)ࢆ౑⏝ࡋ ࡓࠋCu๓㥑య࡜ࡋ࡚ᮾி໬ᡂᕤᴗ㸦ᰴ㸧〇ࡢࣅࢫ㸦2,2,6,6- ࢸࢺ࣓ࣛࢳࣝ-3,5-࣊ࣉࢱࣥࢪ࢜ࢼࢺ㸧㖡㸦ჟ㸧㸦Cu(tmhd)2㸧ࠊ ᐩ ኈ ࣇ ࢕ ࣝ ࣒ ࿴ ග ⣧ ⸆ ᕤ ᴗ 㸦 ᰴ 㸧〇 ࡢ 㓑㓟㖡㸦ჟ㸧㸦Cu(CH3COO)2㸧ࠊᐩኈࣇ࢕࣒ࣝ࿴ග⣧⸆ᕤᴗ㸦ᰴ㸧〇ࡢ◪

㓟㖡㸦ჟ㸧㸦Cu(NO3)2㸧ࡢ୕✀㢮ࢆࠊRu๓㥑య࡜ࡋ࡚ᮾி໬

ᡂᕤᴗ㸦ᰴ㸧〇ࡢࣝࢸࢽ࣒࢘㸦რ㸧࢔ࢭࢳࣝ࢔ࢭࢺࢼ࣮ࢺ

㸦Ru(acac)3㸧ࠊࣝࢸࣀࢭࣥࠊᐩኈࣇ࢕࣒ࣝ࿴ග⣧⸆ᕤᴗ㸦ᰴ㸧

〇ࡢሷ໬ࣝࢸࢽ࣒࢘㸦RuCl3㸧ࡢ୕✀㢮ࢆ౑⏝ࡋࡓࠋࡇࢀࡽ

ࢆ௵ពࡢẚ⋡࡛㓄ྜࡋ࢔ࢭࢺ࡛ࣥ⁐ゎࡋࡓᚋࠊ㉸⮫⏺ CO2

㸦scCO2㸧࡟ࡼࡿྵᾐฎ⌮ࢆ᪋ࡋࡓࠋࡑࡢᚋࠊỈ⣲㑏ඖฎ⌮

࡟ࡼࡾከᏍ㉁SiO2⣽Ꮝෆ࡟࡚Cu-Ru」ྜࢼࣀ⢏Ꮚࢆᙧᡂࡉ ࡏࡓࠋㄪ〇ࡋࡓCu-Ru⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢᢸᣢ ẚ⋡ࡣࠊ࢚ࢿࣝࢠ࣮ศᩓᆺ⺯ගX⥺㸦XRF; ᓥὠ〇సᡤEDX- 8000㸧࡟࡚ホ౯ࡋࡓࠋ

2.2 ඖ⣲࣐ࢵࣆࣥࢢ ከᏍ㉁SiO2࡟ᅛᐃ໬ࡉࢀࡓCu-Ru」

ྜ⢏Ꮚࡣࠊ࢚࣏࢟ࢩᶞ⬡࡟ໟᇙࡋ࡚ࠊ࣑ࢡࣟࢺ࣮࣒ࢆ⏝࠸࡚

ⷧ ⭷ ໬ ࡋ ࡓ ᚋ ࠊ ᗈ 㟁 ᅽ ㉸㧗 ឤ ᗘ ཎ Ꮚ ศ ゎ ⬟ 㟁 Ꮚ 㢧 ᚤ 㙾㸦JEOL; JEM-ARM200CF㸧ࢆ⏝࠸࡚ࠊHAADF-STEM࡜EDX ඖ⣲࣐ࢵࣆࣥࢢീࢆᚓࡓࠋ

2.3 ゐ፹άᛶヨ㦂 స〇ࡋࡓ Cu-Ru ⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏

Ꮚゐ፹࡟ᑐࡋࠊ࣐ࢫࣇ࣮ࣟࢥࣥࢺ࣮࣮ࣟࣛ࡜TCD࢞ࢫࢡࣟ

࣐ࢺࢢࣛࣇ࢕࣮㸦ᓥὠ〇సᡤGC-8A㸧࠿ࡽᵓᡂࡉࢀࡿCO㓟

໬཯ᛂヨ㦂⿦⨨ࢆ⏝࠸ࠊCO㓟໬཯ᛂ࡟ࡼࡾゐ፹άᛶࢆ᳨ウ ࡋࡓࠋㄪ〇ࡋࡓSiO2-CuRu」ྜయ㸦0.1g㸧ࢆ཯ᛂჾࡢ୰࡟࢞

ࣛࢫࣅ࣮ࢬ࡜୍⥴࡟ワࡵࠊCOࠊHeࠊO2ࢆ2㸸78㸸20ࡢ๭ྜ

ࡢΰྜ࢞ࢫࢆ཯ᛂ⟶࡟100 ml㺃min^-1࡛ὶ㏻ࡉࡏࠊ࢞ࢫࢡ࣐ࣟ

ࢺࢢࣛࣇ࢕࣮࡟ࡼࡾ཯ᛂᚋࡢ࢞ࢫ⤌ᡂࢆ ᐃࡋࠊ཯ᛂ⋡ࢆ

Ỵᐃࡋࡓࠋ

3. ⤖ᯝ࠾ࡼࡧ⪃ᐹ

3.1 Ru ࠾ࡼࡧ Cu ࡢ SiO2࡟ᑐࡍࡿ྾╔㔞࠾ࡼࡧゐ፹άᛶ

ᅗ3࡜⾲2࡟ᮏ◊✲࡛౑⏝ࡋࡓ஧ẁ㝵⣽ᏍSiO2ࡢSEM࡜

❅⣲྾╔ἲ࡟ࡼࡾ ᐃࡋࡓ஧ẁ㝵⣽ᏍSiO2ࡢẚ⾲㠃✚➼ࡢ

≀ᛶ್ࢆ♧ࡍࠋ㉸⮫⏺ྵᾐฎ⌮࡟࠾ࡅࡿCu࡜Ruࡢ๓㥑య ࡢ᭱㐺໬࡟ࡘ࠸࡚ࠊከᏍ㉁ࢩࣜ࢝࡟ᑐࡍࡿ๓㥑యࡢ྾╔㔞

࠾ࡼࡧゐ፹άᛶࡢⅬ࠿ࡽホ౯ࡋࡓࠋᅗ4࡟Cu࠾ࡼࡧRuࡢ ๓㥑యࡢ྾╔㔞ࢆ♧ࡍࠋ๓㥑యࡢࢩࣜ࢝࡟ᑐࡍࡿ྾╔㔞ࡸ

㉸⮫⏺┦࡟ᑐࡍࡿ⁐ゎ≉ᛶࡢ㐪࠸࡟ࡼࡾ྾╔㔞ࡀ኱ࡁࡃኚ

(4)

໬ࡋ࡚࠸ࡿࡇ࡜ࡀࢃ࠿ࡿࠋࡲࡓࠊCu࠾ࡼࡧRuࢼࣀ⢏Ꮚࢆ

ᢸᣢࡋࡓSiO2ࡢCO㓟໬άᛶ࡟ཬࡰࡍ๓㥑యࡢᵓ㐀ࡢᙳ㡪

ࢆᅗ5, 6࡟♧ࡍࠋ๓㥑యࡢ㐪࠸࡟ࡼࡾࠊゐ፹άᛶࡀ኱ࡁࡃ␗

࡞ࡿࡇ࡜ࡀࢃ࠿ࡿࠋ

ᅗ3 ஧ẁ㝵⣽Ꮝᵓ㐀ࢆ᭷ࡍࡿSiO2ࡢSEM㸦ᕥᅗ; పಸ

⋡ࠊྑᅗ; 㧗ಸ⋡㸧

Fig. 3. SEM images of dual-pore monolithic SiO2 (left; lower magnification, right; higher magnification).

⾲2 ஧ẁ㝵⣽ᏍSiO2(DPS)ࡢ≀ᛶ್

Table 2. Properties of dual-pore monolithic SiO2(DPS).

BET surface area [m²㺃g^-1]

Pore volume [cm³㺃g^-1]

Pore diameter [nm]

587 0.642 4.4

ᅗ4 Cu(ୖᅗ)࠾ࡼࡧRu㸦ୗᅗ㸧๓㥑యࡢ஧ẁ㝵⣽ᏍSiO2

࡬ࡢ྾╔㔞ࡢẚ㍑

Fig. 4. Adsorption amounts of Cu and Ru precursors on dual-pore monolithic SiO2.

3.2 ඖ⣲࣐ࢵࣆࣥࢢ࡟ࡼࡿほᐹ ᅗ 7 ࡟㉸⮫⏺ྵᾐฎ⌮࡟

ࡼࡾ஧ẁ㝵⣽ᏍSiO2࡟ᅛᐃ໬ࡉࢀࡓࠊCu-Ru」ྜࢼࣀ⢏Ꮚ

ࡢHAADF-STEMീ࡜EDXඖ⣲࣐ࢵࣆࣥࢢࡢศᯒ⤖ᯝࢆ♧

ࡋࡓࠋᅗ7ࢆ☜ㄆࡋࡓ࡜ࡇࢁࠊ஧ẁ㝵⣽ᏍSiO2ୖ࡟Cu࡜ Ruࡀᆒ୍࡟ศᩓࡋࠊᅛᐃ໬ࡉࢀ࡚࠸ࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓࠋ

ࡲࡓࠊࡑࢀࡒࢀࡢඖ⣲ࡢࢼࣀ⢏Ꮚࡀ㔜࡞ࡗ࡚Ꮡᅾࡋ࡚࠸ࡿ

ࡇ࡜࠿ࡽࠊࢼࣀ࡛ࣞ࣋ࣝ」ྜࡋ࡚࠸ࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓࠋࡇ ࡢEDXࢫ࣌ࢡࢺࣝࡼࡾࠊCu࡜Ruࡢࣆ࣮ࢡࡀ☜ㄆ࡛ࡁࡿࠋ ࡇࡢࡇ࡜࠿ࡽࡶCu࡜Ruࡢ୧᪉ࡢඖ⣲ࡀᢸయࡢ⣽Ꮝෆ࡟༑

ศ࡟Ꮡᅾࡋ࡚࠸ࡿࡇ࡜ࡀ☜ㄆ࡛ࡁࡓࠋ

ᅗ5 Cuࢼࣀ⢏Ꮚࢆᢸᣢࡋࡓ஧ẁ㝵⣽ᏍSiO2ࡢCO㓟໬ά ᛶ࡟ཬࡰࡍCu๓㥑యࡢᵓ㐀ࡢᙳ㡪

Fig. 5. Effect of Cu precursor on the temperature dependence of the CO oxidation reaction by Cu@SiO2.

ᅗ6 Ruࢼࣀ⢏Ꮚࢆᢸᣢࡋࡓ஧ẁ㝵⣽ᏍSiO2ࡢCO㓟໬ά ᛶ࡟ཬࡰࡍRu๓㥑యࡢᵓ㐀ࡢᙳ㡪

Fig. 6. Effect of Ru precursor on the temperature dependence of the CO oxidation reaction by Ru@SiO2.

3.3 Ru࠾ࡼࡧ Cuࡢ๓㥑యࡢ᭱㐺໬ ㉸⮫⏺ྵᾐฎ⌮࡟࠾

ࡅࡿCu࡜Ruࡢ๓㥑యࡢ㓄ྜẚ⋡࡜ࠊከᏍ㉁SiO2࡟ᅛᐃ໬

ࡉࢀࡓࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚࡢᢸᣢẚ⋡ࡢ㛵ಀࢆᅗ8࡟♧ࡍࠋ

⦪㍈࡟ࡣࢼࣀ⢏Ꮚࡢᢸᣢẚ⋡ࠊᶓ㍈࡟ࡣ๓㥑యࡢ㓄ྜẚ⋡

ࢆ♧ࡋࡓࠋᅗ8ࡼࡾࠊࡑࢀࡒࢀࡢ๓㥑యࡢ㓄ྜẚ⋡ࡀ1:1ࡢ

࡜ࡁࠊCuࡢᢸᣢ๭ྜࡀ 90 wt.%࡟㐩ࡋ࡚࠸ࡿࡇ࡜ࡀ☜ㄆ࡛

ࡁ ࡓ ࠋ ࡇ ࢀ ࡣ ๓ 㥑 య ࡜ ࡋ ࡚ ౑ ⏝ ࡋ ࡚ ࠸ ࡿ Cu(tmhd)2࡜

(5)

ᯇᒣ Ύ

Ru(acac)3ࡢࡑࢀࡒࢀࡢ㓄఩Ꮚᩘ࡜⁐ゎᗘࡀཎᅉ࡛࠶ࡿ࡜⪃

࠼ࡽࢀࡓࠋRu(acac)3ࡣCu(tmhd)2࡜ẚ㍑ࡍࡿ࡜㓄఩Ꮚᩘࡀከ ࡃࠊᔞ㧗࠸ᵓ㐀ࢆᙧᡂࡋ࡚࠸ࡿ࡜⪃࠼ࡽࢀࡓࠋࡇࡢࡇ࡜ࡀࡑ

ࢀࡒࢀࡢ྾╔ᗘࡢ┦㐪࡟㉳ᅉࡋ࡚࠸ࡿ࡜⪃ᐹࡉࢀࡿࠋࡑࡢ ࡓࡵࠊศᩓ⁐፹୰࡛ࡢࡑࢀࡒࢀࡢ๓㥑యࡢ⃰ᗘࢆ⪃៖ࡍࡿ

ᚲせᛶࡀ࠶ࡿ࡜ᣦ᦬ࡉࢀࡓࠋ

ᅗ7 ㉸⮫⏺ὶయྵᾐἲ࡟ࡼࡾ஧ẁ㝵⣽ᏍSiO2࡟ᢸᣢࡉࢀ

ࡓCu-Ru」ྜ⢏ᏊࡢHR-TEM࠾ࡼࡧHAADF-STEM࡟ࡼࡿ

EDXඖ⣲࣐ࢵࣆࣥࢢࠊ(a)HR-TEMࠊ(b)HAADF-STEMࠊ (c)RuࡢEDXඖ⣲࣐ࢵࣆࣥࢢࠊ(d)CuࡢEDXඖ⣲࣐ࢵࣆࣥ

ࢢࠊ(e) Cu࡜RuࡢEDXඖ⣲࣐ࢵࣆࣥࢢࡢ㔜ࡡྜࢃࡏࠊ

(f)EDXࢫ࣌ࢡࢺࣝ

Fig. 7. (a)HR-TEM, (b)HAADF-STEM of CuRu@SiO2, (c)Ru-L STEM EDX map (red), (d) Cu-L STEM EDX map (blue), (e)overlay image of the maps shown in (c) and (d), (f)EDX

spectra.

ᅗ8 ๓㥑యࡢ㓄ྜẚ⋡࡜ࢼࣀ⢏Ꮚᢸᣢẚ⋡

Fig. 8. Effect of the precursor ratios in the reaction feeds on the final composition of CuRu bimetallic nanoparticles in the

mesopores in the hierarchical SiO2.

3.4 ゐ፹άᛶヨ㦂 ᅗ9࡟௵ពࡢẚ⋡࡛ㄪ〇ࡋࡓCu-Ru⣔ ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢゐ፹άᛶヨ㦂ࡢ⤖ᯝࢆ♧ࡋࡓࠋ ከᏍ㉁SiO2࡟Ruࡢࡳࢆᢸᣢࡋࡓሙྜࢆ0%ࠊCuࡢࡳࢆᢸ ᣢࡋࡓሙྜࢆ100 %࡜ࡋ࡚⟬ฟࡋࡓࠋࡲࡓࠊᅗ9(b)࡟ࡣࠊᅗ 9(a)ࡢヨ㦂⤖ᯝ࠿ࡽ⟬ฟࡋࡓT50್㸦CO㓟໬཯ᛂࡀ50 %㐍

⾜ࡋࡓ ᗘ㸧ࢆࡲ࡜ࡵ࡚♧ࡋࡓࠋᅗ9(b)ࡼࡾCuࡢࡳࡶࡋࡃ ࡣRuࡢࡳࢆᢸᣢࡉࡏࡓሙྜ࡛ࡣࠊT50್ࡀ210 ႏ, 185 ႏ࡜ 㧗࠸್ࢆ♧ࡋࡓࡇ࡜࠿ࡽࠊCO㓟໬άᛶࡀప࠸ࡇ࡜ࡀࢃ࠿ࡗ ࡓࠋࡇࢀ࡟ᑐࡋCu࡜Ruࡢẚ⋡ࡀ1:1࡟㏆࡙ࡃ࡜ࠊT50್ࡀ Rhࡼࡾࡶప࠸⣙140 ႏࡲ࡛పୗࡍࡿࡇ࡜ࡀ☜ㄆ࡛ࡁࡓࠋࡇ ࡢࡇ࡜࠿ࡽࠊࡑࢀࡒࢀࡢࢼࣀ⢏Ꮚࡀྠࡌẚ⋡࡛ᢸᣢࡉࢀ࡚

࠸ࡿሙྜࡣࠊCuࡢ㓟⣲ぶ࿴ᛶ࡜RuࡢCO྾╔ᛶࡀ」ྜ໬

ࡉࢀࠊࡇࢀࡽࡀඹᏑࡋࡓ࡜ࡁࡢ┦஫స⏝࡛ࠊCO㓟໬άᛶࡀ

ୖ᪼ࡍࡿ࡜⪃࠼ࡽࢀࡿࠋ

ᅗ10(a)࡟ࠊRhࠊRuࠊCuࠊCu-Ru(≀⌮ΰྜ)ࠊCu-RuࠊPd-Ru

ࢆᢸᣢࡉࡏࡓሙྜࡢ CO 㓟໬άᛶホ౯ࡢ⤖ᯝࢆࡲ࡜ࡵ࡚♧

ࡋࡓࠋࡇࡢ࡜ࡁࠊCu-Ru⣔࡜Pd-Ru⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚ ゐ፹࡟㛵ࡋ࡚ࡣࠊάᛶࡀ᭱ࡶ㧗࠿ࡗࡓᢸᣢẚ⋡1:1ࡢࣂ࢖࣓

ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢ ᐃ⤖ᯝࢆ⾲♧ࡋࡓࠋࡲࡓࠊᅗ10(b)࡟ࠊ

ᅗ10(a)ࡢCO㓟໬άᛶホ౯ࡢ⤖ᯝ࠿ࡽ⟬ฟࡋࡓྛヨᩱࡢT50

್㸦COࡢ཯ᛂ⋡ࡀ50 %࡟࠾ࡅࡿ཯ᛂ ᗘ㸧ࢆ♧ࡋࡓࠋ㉸⮫

⏺ྵᾐἲ࡟ࡼࡾㄪ〇ࡋࡓ Cu-Ru⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ

፹ࡣࠊ༢㔠ᒓࡢࡳࢆᢸᣢࡋࡓሙྜ࡜≀⌮ΰྜ࡟ࡼࡿࡶࡢ࡜

ẚ㍑ࡍࡿ࡜ࠊప࠸T50್ࢆ♧ࡋࡓࠋࡇࡢࡇ࡜ࡼࡾࠊ2✀㢮ࡢ 㔠ᒓࡀࢼࣀ࡛ࣞ࣋ࣝ」ྜ໬ࡍࡿࡇ࡜࡟ࡼࡾάᛶࡀୖ᪼ࡍࡿ

ࡇ࡜ࡀ♧၀ࡉࢀࡓࠋ୍᪉ࠊ༢⣧࡞ࢼࣀ⢏Ꮚࡢᢸᣢࡉࢀࡓ஧ẁ 㝵⣽ᏍSiO2࡛ࡣࠊ኱ࡁࡃゐ፹άᛶࡀྥୖࡋ࡞࠿ࡗࡓࡇ࡜࠿

ࡽࡶࠊࢼࣀ࡛ࣞ࣋ࣝࡢCu࡜Ruࡢ」ྜ໬ࡀࠊゐ፹άᛶࡢྥ

ୖ࡟ࡘ࡞ࡀࡗ࡚࠸ࡿࡇ࡜ࡀᐤ୚ࡋ࡚࠸ࡿࡶࡢ࡜⪃ᐹࡉࢀࡿࠋ

ᅗ9 Cu-Ru⣔ࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢ㓄ྜẚ⋡ࡀCO

㓟໬ヨ㦂࡟ཬࡰࡍᙳ㡪ࠊ(a)CO㓟໬ヨ㦂࡟ཬࡰࡍ㓟໬ ᗘ ࡢᙳ㡪ࠊ(b)T50್࡟ཬࡰࡍᢸᣢẚ⋡ࡢᙳ㡪 Fig. 9. (a)Effect of the metal composition of CuRu nanoparticles

on the temperature dependence of the CO oxidation reaction, (b)relationship between the amount of Cu inCuRu@SiO2 and T50

(temperature at which the conversion of CO to CO2 reaches 50 %).

(6)

ࡲࡓࠊCu-Ru⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡢT50್ࡣࠊRh

ࡼࡾࡶప࠸⣙140ႏ࡛࠶ࡾࠊప ᗘ࡟࠾࠸࡚ࡶゐ፹άᛶࢆ♧

ࡍࡇ࡜ࡀࢃ࠿ࡗࡓࠋࡲࡓ Pd-Ru ⣔ࡢࣂ࢖࣓ࢱࣝࢼࣀ⢏Ꮚゐ

፹ࡢT50್࡜ẚ㍑ࡍࡿ࡜ࠊ࠾஫࠸࡟⣙140 ႏ࡛ゐ፹άᛶࢆ᭷

ࡋࡓࡓࡵࠊࡇࢀࡽࡣ㏆࠸ゐ፹άᛶࢆᣢࡘ࡜࠸࠺ࡇ࡜ࡀ☜ㄆ

࡛ࡁࡓࠋ

ᅗ10 ከᏍ㉁SiO2࡟ᢸᣢࡋࡓRhࠊRuࠊCuࠊCu-RuࠊPd- Ruࢼࣀ⢏Ꮚゐ፹ࡢCO㓟໬ヨ㦂ࠊ(a)CO㓟໬ヨ㦂࡟ཬࡰࡍ

㓟໬ ᗘࡢᙳ㡪ࠊ(b)T50್࡟ཬࡰࡍඖ⣲ࡢᙳ㡪 Fig. 10. (a)Temperature dependence of the oxidation of CO promoted by CuRu, Rh, Cu, Ru, and Cu + Ru nanoparticles immobilized on hierarchical porous SiO2, (b)relationship between

the CuRu, Rh, Cu, Ru, Cu + Ru nanoparticles immobilized on hierarchical porous SiO2 and T50 (temperature at which the

conversion of CO to CO2 reaches 50 %).

4. ⤖ゝ

㉸⮫⏺ྵᾐἲ࡟ࡼࡾࠊከᏍ㉁SiO2ࡢ⣽Ꮝ୰࡟Cu࡜Ruࡑ

ࢀࡒࢀࡢࢼࣀ⢏Ꮚࢆ」ྜ໬࣭ᅛᐃ໬ࡋࠊCu-Ru⣔ࣂ࢖࣓ࢱࣝ

ࢼࣀ⢏Ꮚゐ፹ࢆྜᡂࡍࡿࡇ࡜ࡀ࡛ࡁࡓࠋࡲࡓࠊHAADF-STEM ࡢEDXඖ⣲࣐ࢵࣆࣥࢢ࡟ࡼࡾࠊCu࡜Ruࡢ」ྜࢼࣀ⢏Ꮚࡢ ᵝᏊࢆ☜ㄆࡍࡿࡇ࡜ࡀ࡛ࡁࡓࠋࡇࡢゐ፹࡟ࡘ࠸࡚CO㓟໬཯

ᛂ࡟ࡼࡾゐ፹άᛶヨ㦂ࢆ⾜ࡗࡓ࡜ࡇࢁࠊCu-Ruࡢᢸᣢẚ⋡ࡀ 1:1௜㏆ࡢ࡜ࡁ࡟T50್ࡀ⣙140 ႏࢆ♧ࡋࠊ᭱ࡶ㧗࠸άᛶࢆ

ᣢࡘࡇ࡜ࡀ☜ㄆࡉࢀࡓࠋࡉࡽ࡟ࠊྜᡂࡋࡓ Cu-Ru⣔ࡢࣂ࢖

࣓ࢱࣝࢼࣀ⢏Ꮚゐ፹ࡣࠊRhࡼࡾࡶඃࢀࡓゐ፹άᛶࢆ᭷ࡍࡿ

ࡇ࡜ࡀࢃ࠿ࡗࡓࠋ

5. ㅰ㎡

ᮏ◊✲ࡣ⚟ᒸᕤᴗ኱Ꮫ⥲ྜ◊✲ᶵᵓ࢚ࣞࢡࢺࣟࢽࢡࢫ◊

✲ᡤࡢ2019ᖺᗘ᪂௵ࢫࢱ࣮ࢺ࢔ࢵࣉᨭ᥼ไᗘ࡟ࡼࡾᐇ᪋ࡋ ࡓࡶࡢ࡛࠶ࡿࠋ

ᩥ ⊩

(1) ᳃ୗ♸୍, ㈨※ᆅ㉁, Vol.63(1), pp.21-30(2013)

(2) ⸨Ọබ୍㑻, Ᏻᕝ࿴Ꮥ, 㧘㇂㞝ኴ㑻, ኱⏣㞙୍㑻, ୰ᮧㅬኴ㑻, ຍ⸨

Ὀᾈ, ᪂ࡓ࡞῝ᾏᗏ㖔≀㈨※“ࣞ࢔࢔࣮ࢫἾ”ࡢ᥈ᰝ࡜ 㛤Ⓨ࡟ྥࡅ ࡓྲྀࡾ⤌ࡳ, J. MMIJ, Vol.131, pp.648-655(2015)

(3) ᚚᡭὙᐜᏊ, Bao Zebin, ᮧୖ⚽அ, 㜿㒊ⱥᶞ, ᯇඖ㐩, ⓑ㔠᪘㔠ᒓࡢ

ຠ⋡ⓗ฼⏝, J. Japan Inst. Metals, Vol.75, pp.10-20(2011)

(4) Q. Zhang, K. Kusada, D. Wu, T. Yamamoto, T. Toriyama, S. Matsumura, S.

Kawaguchi, Y. Kubota, and H. Kitagawa, Nature Communications, Vol.9, 510(2018)

(5) F. Wang, K. Kusada, D. Wu, T. Yamamoto, T. Toriyama, S. Matsumura, Y.

Nanba, M. Koyama, and H. Kitagawa, Angew. Chem. Int. Ed., Vol.57, pp.4505-4509 (2018)

(6) C. Rosler, D. Esken, C. Wiktor, H. Kobayashi, T. Yamamoto, S. Matsumura, H. Kitagawa, and R. A. Fischer, Eur. J. Inorg. Chem., Vol.2014, pp.5514- 5521(2014)

(7) K. Kusada, H. Kobayashi, R. Ikeda, Y. Kubota, M. Takata, S. Toh, T.

Yamamoto, S. Matsumura, N. Sumi, K. Sato, K. Nagaoka, and H. Kitagawa, J. American Chem. Soc., Vol.136, pp.1864-1871(2014)

(8) K. Sato, H. Tomonaga, T. Yamamoto, S. Matsumura, N.D.B. Zulkifli, T.

Ishimoto, M. Koyama, K. Kusada, H. Kobayashi, H. Kitagawa, and K.

Nagaoka, Scientific Reports, Vol.6, 28265(2016)

(9) B. Huang, H. Kobayashi, T. Yamamoto, S. Matsumura, Y. Nishida, K. Sato, K. Nagaoka, S. Kawaguchi, Y. Kubota, H. Kitagawa, J. America Chem.

Soc., Vol.139, pp.4643-4646(2017)

(10) I. Ushiki, K. Matsuyama, R.L. Smith, Chapter 15 - Sustainable Approaches for Materials Engineering with Supercritical Carbon Dioxide, in: G.

Szekely, A. Livingston (Eds.) Sustainable Nanoscale Engineering, Elsevier 2020, pp. 395-414.

(11) S.E. Bozba÷, and C. Erkey, J. Supercritical Fluids, Vol.96, pp.298- 312(2015)

(12) M. Türk, and C. Erkey, J. Supercritical Fluids, Vol.134, pp.176-183(2018) (13) S.N. Tripathi, S.R. Bharadwaj, and S.R. Dharwadkar, J. Phase Equilibria,

Vol.14, pp.638–642(1993)

(14) H. Okamoto, J. Phase Equilibria, Vol.13, pp.440(1992)

(15) K. Matsuyama, S. Tanaka, T. Kato, T. Okuyama, H. Muto, R. Miyamoto, and H. Bai, J. Supercritical Fluids, Vol.130, pp.140-146(2017)

(16) K. Matsuyama, M. Motomura, T. Kato, T. Okuyama, and H. Muto, Microporous and Mesoporous Materials, Vol.225, pp.26-32(2016) (17) K. Matsuyama, N. Tomiyasu, K. Inoue, R. Yokomizo, T. Okuyama, and

H.Muto, J. Supercritical Fluids, Vol.160, 104818(2020)

(18) T. Yamada, A. Ogawa, H. Masuda, W. Teranishi, A. Fujii, K. Park, Y.

Ashikari, N. Tomiyasu, T. Ichikawa, R. Miyamoto, H. Bai, K. Matsuyama, A. Nagaki, and H. Sajiki, Catalysis Science & Technology, in press (19) Y. Ashikari, K.Maekawa, M. Takumi, N. Tomiyasu, C. Fujita, K.

Matsuyama, R. Miyamoto, H. Bai, and A. Nagaki, Catalysis Today, in press

福岡工業大学 学術機関リポジトリ