• Title/Summary/Keyword: adlineation sites

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Effect of Temperature on $H_2$ Spillover over $Pt/H_xMoO_3$ (Pt를 담지한 $H_xMoO_3$촉매의 수소 이동 속도에 미치는 온도의 영향)

  • 김진걸
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.2
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    • pp.114-117
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    • 2004
  • Rates of $H_2$ uptake into $Pt/MoO_3$ were measured for the noncalcined and $200^{\circ}C$ calcined $Pt/MoO_3$. Amount of $H_2$ uptake for $200^\circ{C}$calcined $Pt/MoO_3$ was greater than the amount of noncalcined $Pt/MoO_3$. From these two experiments, it was found that the rates of $H_2$ desorption were proportional to the increase of desorption temperature. XPS demonstrated that Cl reduced more faster in ITR after calcination at $200^{\circ}C$. This inducd smaller amount of residual chlorine at adlineation sites between Pt and $MoO_3$ substrates. This resulted in opening the more channel of hydrogen pathway into more $MoO_3$particles and controled the kinetics of hydrogen uptake.

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Hydrogen Spillover Kinetics - I. Effect of Surface Morphology on [$Pt/MoO_{3}$] Catalyst (수소 spillover 속도론 - I. $Pt/MoO_{3}$ 촉매의 표면 형상 변화)

  • Kim Jin Gul;Kim Seong-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.6
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    • pp.491-494
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    • 2004
  • [ $H_2$ ] uptake into $Pt/MoO_{3}$ was enhanced with an increased calcination temperature. Selective CO pulse chemisorption demonstrated that free Pt surface area was decreased as calcination temperature was increased. Characteristic techniques were dedicated to elucidate the closer contact at adlineation sites between Pt and $MoO_3$ substrates. Calcination resulted in supplying the hydrogen access into more $MoO_3$ particles and controlling the kinetics of hydrogen uptake.

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Effect of Calcination on Hydrogen Adsorption and Desorption in Pt/MoO3/SiO2 (소성 조건이 Pt/MoO3/SiO2 촉매의 수소 흡착 및 탈착에 미치는 영향)

  • Cho Sae Jung;Lee Ju Heon;Cho Ji Eun;Kim Seong-Soo;Kim Jin Cul
    • Proceedings of the KAIS Fall Conference
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    • 2004.11a
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    • pp.277-279
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    • 2004
  • $300^{\circ}C$ 소성 Pt/MoO3가 수소를 흡착후 탈착하는 속도를 측정하였다. 두가지 흡착 속도를 나타내는 Pt/MoO3 촉매에서 탈착량은 흡착량과 탈착 온도의 증가에 비례하는 것을 알 수 있었다. 또한 X-Ray Photoelectron Spectroscope(XPS) 결과로부터 Pt와 MoO3간의 활성점에 존재하는 Cl의 존재가 수소 이동 속도를 결정하는 것으로 판단되었다.

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Effect of an Adsorbed Residual Chlorine at Adlineation Sites over Formation of $Pt/HxMoO_3$ (활성점에 흡착된 잔존 chlorine이 $Pt/HxMoO_3$ 생성에 미치는 영향)

  • Jin Gul, Kim;Seong-Soo, Kim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.4
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    • pp.282-285
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    • 2004
  • Kinetics of H-spillover over $Pt/MoO_3$ was greatly affected by the amount of residual chlorine differing by calcination temperature. Multifacetted techniques for characterization were dedicated to elucidate the faster reduction of chlorine in the isothermal reduction (ITR) at $50^circ{C}$ after calcination. Reduction of residual chlorine over Platinum resulted in opening the more channel of hydrogen pathway into more $MoO_3$ particles and controlling the kinetics of hydrogen uptake.

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