J. Inst. Electrostat. Jpn.

, 31, 2 (2007) 78 79

ᄢ᳇࿶㉄⚛ࡊ࡜࠭ࡑߦࠃࠆ㊄࠽ࡁ☸ሶ⸅ᇦߩૐ᷷ౣ↢⾫ᄐ‫ܫ‬㧘દ㆐㊄ᱜ๺‫ܫ‬㧘ဝ↰ᐕ‫ܫ‬㧘የᒻᢕ‫ܫ‬㧘ੑ࠲᧛᫪‫ܫ‬(2006 ᐕ 12 ᦬ 6 ᣣฃઃ㧘2006 ᐕ 12 ᦬ 27 ᣣฃℂ)

Low Temperature Regeneration of Gold Nanoparticle Catalyst Using
Atmospheric Pressure Oxygen Plasma
Hyun-Ha KIM,‫ܫ‬,1 Masakazu DATÉ,‫ ܫ‬Susumu TSUBOTA,‫ ܫ‬Atsushi OGATA‫ܫ‬and Shigeru FUTAMURA‫ܫ‬(Received December 6, 2006; Accepted December 27, 2006)

Oxygen plasma was applied to the low temperature regeneration of the deactivated nanometer sized gold(Au) supported on titanium dioxide (TiO2). The Au/TiO2 catalyst, prepared by a deposition-precipitation method,
exhibited a very high catalytic activity for the oxidation of 1000 ppm CO in air. The initial activity completely
disappeared when the catalyst was used in the plasma-driven catalysis of 200 ppm benzene. Oxygen plasma
treatment of the deactivated Au/TiO2 catalyst recovered catalytic activity up to 88% at 22000 h-1.
1.

ߪߓ߼ߦ

hyun-ha.kim@aist.go.jpૐ᷷ࡊ࡜࠭ࡑᛛⴚࠍ↪޿ߚើ⊒ᕈ᦭ᯏൻว‛㧔એਅ VOC㧕ߩ㉄⚛ࡊ࡜࠭ࡑߦࠃࠆౣ↢ᴺߪേ૞᷷ᐲ߇ቶ᷷ߢ޽ࠆߩಽ⸃ߦ߅ߌࠆ⺖㗴ߩ৻ߟߣߒߡ㧘CO ߩ↢ᚑᛥ೙ߣ CO㧞ߚ߼㧘ᾲߦࠃࠆ㊄࠽ࡁ☸ሶߩಝ㓸ࠍ㒐ߋߎߣ߇ᦼᓙߢ߈ࠆ㧚ߩ෼₸ะ਄߇᜼ߍࠄࠇࠆ㧚᳇⋧࡜ࠫࠞ࡞෻ᔕߦࠃࠆ CO ㉄
ൻߪᲧセ⊛ㆃ޿ߚ߼㧘ૐ᷷ࡊ࡜࠭ࡑන⁛ߢ CO ࠍ CO2 ߦቢో㉄ൻߔࠆߩߪ࿎㔍ߢ޽ࠆ㧚Pt ߿ Rd ╬ߩ⾆㊄ዻ⸅ᇦߪoCO ㉄ൻ෻ᔕߦᵴᕈࠍ␜ߔ߇㧘200 C ⒟ᐲߩ㜞޿᷷ᐲ߇ᔅo2.

ታ㛎ᧄ⎇ⓥߢߪ㧘㉄ൻ࠴࠲ࡦ㧔TiO2㧕ࡍ࡟࠶࠻ߩ㧔ᐔဋ☸ᓘ

1.8 mm㧕਄ߦᨆ಴ᴉᲚᴺ (deposition-precipitation method㧘ⷐߢ޽ࠆ㧚⸅ᇦጀߩ೨Ბߢࠝ࠱ࡦࠍᷝടߔࠆߣ㧘100 C એએਅ DP ᴺ)ߦࠃࠅ㊄࠽ࡁ☸ሶࠍᜂᜬߐߖ㧘CO ㉄ൻࠍᜰᮡ1),෻ᔕߣߒߡ⸅ᇦᵴᕈࠍ⹏ଔߒߚ㧚㊄ߩᜂᜬ㊂ߪ 2wt%ߣߒ

㧚৻ᣇ㧘㉄ൻ‛⴫㕙ߦᜂᜬߒߚ☸ᓘ 10 nm એਅߩ㊄⸅ᇦߚ㧚㊄࠽ࡁ☸ሶ⸅ᇦߩᒻ⁁߅ࠃ߮ࠨࠗ࠭ߪ㧘TEM (Hitachiߪቶ᷷એਅߢ߽ಽሶ⁁㉄⚛ࠍ↪޿ߚ CO ㉄ൻ෻ᔕߦ㕖Ᏹ

Co., H9000NAR)ߦࠃࠅⷰኤߒߚ㧚࿑ 1 ߦ෻ᔕེߩ᭎⇛࿑ࠍ

ਅߢ߽ CO ㉄ൻ෻ᔕ߇ଦㅴߐࠇࠆߎߣ߇ႎ๔ߐࠇߡ޿ࠆ
2)3), 4)

㧚㊄࠽ࡁ☸ሶ⸅ᇦߪ☸ᓘଐሽᕈ߇ᄢ

␜ߔ㧚ౝᓘ 13 mm,᦭ല㐳 200 mm ߩ⍹⧷▤ߩਛߦ㜞㔚࿶߈ߊ㧘10 nm એਅߢߥ޿ߣᵴᕈࠍ⊒⃻ߒߥ޿ߚ߼㧘⸅ᇦౣ㔚ᭂߣߒߡࠦࠗ࡞⁁ߩࠬ࠹ࡦ࡟ࠬࡢࠗࡗ࡯ࠍᝌ౉ߒߚ㧚㉄↢ᤨߩಝ㓸ߦࠃࠆᄬᵴࠍ㒐ߋߦߪ㧘ടᾲߦࠃࠄߥ޿⸅ᇦౣ⚛ࡊ࡜࠭ࡑߪᄬᵴߒߚ⸅ᇦߩౣ↢ߩ㓙ߦߩߺශടߒ㧘CO↢ᛛⴚ߇ᦸ߹ࠇࠆ㧚ߎࠇ߹ߢᄬᵴߒߚ㊄࠽ࡁ⸅ᇦߩૐ᷷ౣߩ㉄ൻ෻ᔕߪࡊ࡜࠭ࡑࠍශടߖߕߦቶ᷷ߢⴕߞߚ㧚෻ᔕེ↢ᛛⴚߣߒߡ⚡ᄖ✢ࠍᾖ኿ߔࠆᣇᴺ߇ႎ๔ߐࠇߡ޿ࠆ߇㧘ߦలႯߒߚ Au/TiO2 ⸅ᇦߩ㊂ߪ߅ࠃߘ 25 cm3 ߢ޽ࠆ㧚㉄⚛

ಣℂᤨ㑆߇㐳ߊ㧘⸅ᇦߦኻߔࠆᾖ኿ߩဋ৻ᕈ╬ߦᡷༀ߇᳞

ࡊ࡜࠭ࡑߩ᡼㔚㔚ജߣಣℂᤨ㑆ߪߘࠇߙࠇ 10. 9 W ߣ 30߼ࠄࠇߡ޿ࠆ㧚ಽߣߒߚ㧚ࡊ࡜࠭ࡑߩ⊒↢ߦߪ㧘AC 㜞㔚࿶㧔30 kVp-p, 300ߦ㜞޿ᵴᕈࠍ␜ߔᧄ⎇ⓥߢߪ㧘ᄬᵴߒߚ㊄࠽ࡁ☸ሶ⸅ᇦߩૐ᷷ౣ↢ᴺߣߒ

Hz㧕ࠍ૶↪ߒߚ㧚᡼㔚㔚ജߪ㧘V-Q ࡝ࠨ࡯ࠫࡘࡊࡠࠣ࡜ߡᄢ᳇࿶㉄⚛ࡊ࡜࠭ࡑߩㆡ↪น⢻ᕈߦߟ޿ߡᬌ⸛ߒߚ㧚ߎࡓ㧔ࠗࡦࠨࠗ࠻␠㧘Ver. 1.72㧕ࠍ↪޿ߡ⸘▚ߒߚ 5)㧚ࠟࠬࠠ࡯ࡢ࡯࠼㧦㉄⚛ࡊ࡜࠭ࡑ㧘㊄࠽ࡁ☸ሶ⸅ᇦ㧘CO ㉄ൻ㧖↥ᬺᛛⴚ✚ว⎇ⓥᚲ㧔305-8569 ⨙ၔ⋵ߟߊ߫Ꮢዊ㊁Ꮉ
16-1 ↥✚⎇⷏㧕
National Institute of Advanced Industrial Science andTechnology (AIST), AIST Tsukuba West, 16-1 Onogawa,Tsukuba, Ibaraki 305-8569, Japan

ᵹ㊂ߪ 4~24 L/min ߩ▸࿐ߢᄌൻߐߖ㧘ⓨ㑆ㅦᐲߩᓇ㗀ࠍ⺞ߴߚ㧚㉄⚛ߣ CO ࠟࠬߩỚᐲߪߘࠇߙࠇ 20㧑ߣ 1000 ppmߣߒߚ㧚FTIR (Perkin Elmer, Spectrum One)ࠍ↪޿ߚ CO ߩ
ቯ㊂ಽᨆߢߪ㧘ࠝ࠱ࡦߦࠃࠆᐓᷤࠍㆱߌࠆߚ߼ᵄᢙ 2162
cm-1 ߩ CO ๆ෼ࡇ࡯ࠢࠍ↪޿ߚ㧚

79 (39)

Ground electrodeAu/TiO2

CO oxidation efficiency (%)

100

Fresh Au/TiO2
80

Regenerated Au/TiO2
using oxygen plasma

60
40

Deactivated Au/TiO2

20

AC high voltage

࿑10෻ᔕེߩ᭎⇛࿑

030000࿑ 2 ߦ㧘㊄࠽ࡁ☸ሶ⸅ᇦߦࠃࠆ CO ㉄ൻ෻ᔕߩᵴᕈࠍ␜ߔ㧚DP ᴺߢ⺞⵾ߒߚ㊄࠽ࡁ☸ሶߩ☸ᓘߪ⸅ᇦᵴᕈ߇㜞޿ߣߐࠇߡ޿ࠆ 3 nm ߆ࠄ 7 nm ߦಽᏓߒߡ޿ߚ㧚⺞⵾⋥ᓟߩ
㊄࠽ࡁ☸ሶ⸅ᇦߪ CO ㉄ൻ෻ᔕߦኻߔࠆᵴᕈ߇㕖Ᏹߦ㜞ߊ㧘ⓨ㑆ㅦᐲ 130,000 h-1 ߹ߢ 98㧑એ਄ߩォൻ₸ࠍ␜ߒߚ㧚ߒ߆ߒ㧘෻ᔕߒߚ CO ߪ 100㧑ߩ෼₸ߢ CO2 ߦォ឵ߐࠇߚ㧚
10 ᤨ㑆߶ߤࡊ࡜࠭ࡑࠍශടߒߥ߇ࠄࡌࡦ࠯ࡦಽ⸃෻ᔕߦ

90000

120000-1Space velocity (h )Fig. 1 Schematic diagram of the reactor.
3. ⚿ᨐߣ⠨ኤ

60000

࿑2㊄࠽ࡁ☸ሶ⸅ᇦߩ CO ㉄ൻ෻ᔕߦኻߔࠆᵴᕈ㧔ቶ᷷㧘㉄⚛ࡊ࡜࠭ࡑߦࠃࠆᄬᵴ⸅ᇦߩౣ↢㧧10.9 W, 30 ಽಣℂ)
Fig. 2 CO oxidation by Au nanoparticle catalyst (roomtemperature, Regeneration of deactivated catalyst using oxygenplasma; 10.9 W, 30 min).
4. ߹ߣ߼㉄ൻ࠴࠲ࡦ਄ߦᨆ಴ᴉᲚᴺߦࠃࠅ⺞⵾ߒߚ☸ᓘ 10 nm
એਅߩ㊄࠽ࡁ☸ሶ⸅ᇦߦࠃࠆ CO ㉄ൻ෻ᔕߦߟ޿ߡᬌ⸛

૶↪ߔࠆߣ㧘CO ㉄ൻᵴᕈߪቢోߦᄬࠊࠇߚ㧚ᄬᵴߩේ࿃

ߒߚ㧚ᧂ૶↪ߩ Au/TiO2 ⸅ᇦߪቶ᷷㧘ⓨ㑆ㅦᐲ 130,000 h-1ߣߒߡߪ㧘ࡌࡦ࠯ࡦಽ⸃෻ᔕߩਛ㑆↢ᚑ‛╬߇㊄࠽ࡁ☸ሶߩ᧦ઙߢ߽ 98%એ਄ߩ㜞޿ CO ㉄ൻᵴᕈࠍ␜ߒߚ㧚৻ᣇ㧘ߩ⴫㕙ߦၸⓍߒ㧘⸅ᇦᵴᕈࠨࠗ࠻߇Ⴇ߇ࠇߚߚ߼ߣ⠨߃ࠄCO ㉄ൻᵴᕈࠍቢోߦᄬߞߚ Au/TiO2 ⸅ᇦߦ㉄⚛ࡊ࡜࠭ࡑࠇࠆ㧚ߎߩೋᦼᵴᕈࠍቢోߦᄬߞߚ Au/TiO2 ⸅ᇦࠍቶ᷷ߢࠍශടߔࠆߎߣߦࠃࠅ㧘ቶ᷷ߢ⸅ᇦߩౣ↢߇น⢻ߢ޽ࠆߎ㉄⚛ࡊ࡜࠭ࡑ㧔᡼㔚㔚ജ 10.9 W㧕ࠍ↪޿ߡ 30 ಽ㑆ಣℂߔߣࠍ᣿ࠄ߆ߦߒߚ㧚ᒰ⹥ᛛⴚߪ㊄࠽ࡁ☸ሶ⸅ᇦߩߺߥࠄߕ㧘ࠆߎߣߦࠃࠅ㧘⸅ᇦᵴᕈ߇㗼⪺ߦ࿁ᓳߐࠇࠆߎߣ߇⏕⹺ߐ৻⥸ߩ⸅ᇦߦኻߒߡ߽⸅ᇦᵴᕈὐߩഠൻࠍᦨዊ㒢ߦߔࠆࠇߚ㧚㉄⚛ࡊ࡜࠭ࡑߢౣ↢ߒߚ Au/TiO2 ⸅ᇦߦౣ߮ 1000ߎߣ߇ߢ߈ࠆౣ↢ᛛⴚߣߒߡᦼᓙߐࠇࠆ㧚ppm ߩ CO ࠟࠬࠍᵹߔߣ㧘ⓨ㑆ㅦᐲߦࠃࠅ⇣ߥࠆ߇ 22,000
h-1 ߢߪ CO ォ឵₸ 88㧑߹ߢᵴᕈ߇࿁ᓳߒߚ㧚ߎࠇߪ㧘ᵴᕈὐࠍⷒߞߡ޿ߚ᦭ᯏ‛߇㉄⚛ࡊ࡜࠭ࡑߦࠃࠅಽ⸃㒰෰ߐࠇߚߚ߼ߣᕁࠊࠇࠆ㧚ⓨ᳇ਛߦ߅ߌࠆૐ᷷ࡊ࡜࠭ࡑߦᲧ
ߴ㉄⚛ࡊ࡜࠭ࡑߢߪ㧘⓸⚛㉄ൻ‛߇↢ᚑߖߕ㧘⸅ᇦ⴫㕙਄ߩ VOC ߿ਛ㑆↢ᚑ‛ࠍࠃࠅല₸ࠃߊ㉄ൻಽ⸃น⢻ߢ޽ࠆ6)㧚ಝ㓸ߦࠃࠅ㊄࠽ࡁ☸ሶߩ☸ᓘ߇ᄢ߈ߊߥࠆߣ CO ㉄ൻᵴᕈߪ⊒⃻ߒߥ޿ߎߣ߆ࠄ㧘㉄⚛ࡊ࡜࠭ࡑߦࠃࠆౣ↢ಣℂᓟߩᵴᕈὐ᭴ㅧߪ଻ߚࠇߡ޿ࠆߣ⠨߃ࠄࠇࠆ㧚㉄⚛ࡊ࡜࠭ࡑߩ᡼㔚㔚ജ߿ಣℂᤨ㑆ࠍᄢ߈ߊߔࠆߣ㧘⸅ᇦᵴᕈߩ࿁ᓳ
ᐲว޿߇ᄢ߈ߊߥࠆߎߣ߇ࠊ߆ߞߡ޿ࠆ㧚੹ᓟ㧘㉄⚛ࡊ࡜࠭ࡑߩ೑↪ᴺࠍ♖ᩏߔࠆߎߣߦࠃߞߡ㧘㊄࠽ࡁ☸ሶ⸅ᇦߩ
ૐ᷷ౣ↢ᴺࠍߐࠄߦᦨㆡൻߢ߈ࠆߣ੍ᗐߐࠇࠆ㧚ෳ⠨ᢥ₂1) A. Naydenov, R. Stoyanova, D. Mehandjiev: J. MolecularCat. A: Chemical, 98 (1995) 92) M. Petersson, D. Jonsson, H. Persson, N. Cruise, B.
Andersson: J. Catal., 238 (2006) 321
3) M. Haruta, N. Yamada, T. Kobayashi, S. Iijima: J. Catal.,
115 (1989) 301
4) M. Daté, Y. Ichihashi, T. Yamashita, A. Chiorino, F. Boccuzzi,
M. Haruta: Catal. Today, 72 (2002) 895) H. H. Kim, A. Ogata, S. Futamura: IEEE Trans. Plasma Sci.,
34 (2006) 986) ㊄⾫ᄐ㧘ᧉᱜᣩ㧘ፕℙ◪㧘๓ᕈᣱ㧘የᒻᢕ㧘ੑ㩊᧛᫪㧦㕒㔚᳇ቇળ⹹㧘29 (2005) 32