• Title/Summary/Keyword: Supported catalyst

검색결과 421건 처리시간 0.02초

부분산화개질 반응에서 촉매의 응집이 촉매 활성에 미치는 영향 (The Effects of Agglomeration of Catalyst on its Activity in Partial Oxidation Reforming)

  • 이상호;윤상호;전승현;배중면
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.203-206
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    • 2009
  • Agglomeration of catalysts is known as one of the major degradation mechanisms. Reforming of liquid fuel, which requires high temperature over $800^{\circ}C$, accelerates agglomeration of catalysts. In this work, The effects of agglomeration on catalysts activity in partial oxidation reforming conditions were investigated. Metal supported catalysts(Pt-CGO, Ru-CGO) were compared to perovskite-structured catalysts(NECS-P1, NECS-P2). High thermal stability of perovskite-structured catalysts was reported. Micro-reactor installed in electric furnace was used. its Temperature was raised from $800^{\circ}C$ to $1000^{\circ}C$ to accelerate agglomeration effect. To measure rate of agglomeration, BET analysis and CO pulse chemisorption were conducted on catalysts exposed to $1100^{\circ}C$. Metal supported catalysts showed degradation at $1000^{\circ}C$ and The rates were different according to metal supported. On the other hand perovskite-structured catalysts showed no degradation at $1000^{\circ}C$.

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$Al_2O_3$ 지지 CaO촉매에 의한 식물유와 혼합지방의 바이오디젤화 (Conversion of Vegetable Oils and Mixed Fat into Biodiesel Using $Al_2O_3$-Supported CaO Catalyst)

  • 현영진
    • 한국응용과학기술학회지
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    • 제27권4호
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    • pp.421-426
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    • 2010
  • The transesterification of rapeseed oil, soybean oil, and mixed fat were conducted at $65^{\circ}C$ with $Al_2O_3$-supported CaO, 0.8 wt% KOH, 1 wt% NaOH and mixed catalyst. The overall conversion(%) of rapeseed oil indicated to be 96% at the 12:1 molar ratio of methanol to oil, 8 wt% CaO and 2 wt% water. The pH ranges of biodiesel for mixed fat using four catalysts and for three fats using 8wt% CaO were 7.3-9.1, 7.3-7.5, respectively. The volumes of water needed to wash biodiesel from rapeseed oil using 0.8 wt% KOH and 8 wt% CaO were 15 mL and 3 mL.

Styrene Epoxidation over Cobalt Cyclam Immobilized SBA-15 Catalyst

  • Sujandi;Prasetyanto, Eko Adi;Han, Sang-Cheol;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • 제27권9호
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    • pp.1381-1385
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    • 2006
  • Cobalt (cyclam) complex has been successfully immobilized onto SBA-15, and proven to be an active catalyst for the epoxidation of styrene with tert-butyl hydroperoxide as a terminal oxidant. The selectivity for styrene oxide was observed to be up to 66% with 40% styrene conversion after 12h reaction time. The reversible redox cycle between Co(III) and Co(II) couple which was supposed to play key role during the epoxidation reaction was supported by a cyclic voltametry analysis. The textural properties of the catalyst was characterized by XRD, N2 adsorption-desorption, and TEM analysis.

CNT 및 CNF를 이용하여 제조된 전극 촉매 및 막 전극 접합체의 특성 (The Characteristic of Prepared Electrode Catalyst and MEA using CNF and CNT)

  • 임재욱;최대규;류호진
    • 마이크로전자및패키징학회지
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    • 제11권1호
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    • pp.59-64
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    • 2004
  • 고분자 전해질 연료전지의 성능은 촉매 지지 물질의 특성에 의존한다. 본 연구에서는 백금 촉매의 지지체로서 CNF(carbon nanofibre)와 CNT(carbon nanotube)를 사용하였다. CNF와 CNT는 기상화학증착법과 메카노케미컬 공정에 의해 처리된 촉매를 이용하여 합성되었다. 백금은 고분자 전해질 연료전지의 적용을 위하여 CNF와 CNT로 지지되었다. 그 결과, 65 nm의 직경을 가지는 twisted CNF로 준비된 MEA가 가장 우수한 I-V 특성을 나타내는 것이 확인되었다.

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Synthesis of High Purity Carbon Nano Fibers and Hydrogen from Propane Decomposition

  • Hussain, S.Tajammul;Gul, Sheraz;Mazhar, M.;Larachi, Faical
    • Bulletin of the Korean Chemical Society
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    • 제29권2호
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    • pp.389-392
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    • 2008
  • High purity carbon nano fibers/tubes (CNF/Ts) which contain 97% pure graphitic carbon are prepared by a new catalytic method. These carbon nano fibers/tubes are ready to use without any further purification. The striking feature of this method is the production of carbon nano fibers/tubes of narrow distribution range. The developed catalytic method also produces pure hydrogen. An additional advantage of this catalytic method is that catalyst can be reused without reactivation. Ni:Cu catalyst system is embodied into SCHOTT-DURAN filter disc of large pore size (40-100 mm). Due to the production of hydrogen in the reaction catalyst stability is enhanced and deactivation process is considerably slowed down.

Co-Ni-P-B/Ni foam 촉매에서 $NaBH_4$ 가수분해를 통한 수소 발생 (Hydrogen Generation from $NaBH_4$ Hydrolysis on Co-Ni-P-B/Ni Foam Catalyst)

  • 박대일;김태규
    • 한국수소및신에너지학회논문집
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    • 제21권5호
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    • pp.383-389
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    • 2010
  • Co-B, Co-P-B, Co-Ni-B and Co-Ni-P-B catalysts supported on Ni foam were prepared using electroless plating in the present study. The surface morphology of the catalysts/Ni foam was observed using SEM and EDS analysis. The Co-Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation due to the uniform formation of catalyst particles on the Ni foam surface. The characteristics of hydrogen generation with Co-Ni-P-B/Ni foam catalyst was investigated at the variety of $NaBH_4$ and NaOH concentrations. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

An important factor for the water gas shift reaction activity of Cu-loaded cubic Ce0.8Zr0.2O2 catalysts

  • Jang, Won-Jun;Roh, Hyun-Seog;Jeong, Dae-Woon
    • Environmental Engineering Research
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    • 제23권3호
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    • pp.339-344
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    • 2018
  • The Cu loading of a cubic $Ce_{0.8}Zr_{0.2}O_2$-supported Cu catalyst was optimized for a single-stage water gas shift (WGS) reaction. The catalyst was prepared by a co-precipitation method, and the WGS reaction was performed at a gas hourly space velocity of $150,494h^{-1}$. The results revealed that an 80 wt% $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalyst exhibits excellent catalytic performance and 100% $CO_2$ selectivity ($X_{CO}=27%$ at $240^{\circ}C$ for 100 h). The high activity of 80 wt% $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalyst is attributed to the presence of abundant surface Cu atoms and the low activation energy of the resultant process.