• Title/Summary/Keyword: supported catalysts

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A Effect of H2O-H2 Pretreatment on VOCs Oxidation over Noble Catalysts on Titania (티타니아에 담지된 귀금속촉매의 H2O-H2 전처리에 따른 휘발성유기화합물 산화에 미치는 영향)

  • Kim, Moon-Chan;Ko, Sun-Hwan
    • Applied Chemistry for Engineering
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    • v.18 no.6
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    • pp.552-556
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    • 2007
  • In this study, noble metals (Pd, Ru, Ir) were supported to $TiO_2$ catalyst. In order to distribute metals uniformly, $H_2O-H_2$ pretreatment technique was used. Xylene, toluene, and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, and XPS analysis. Pd-Ru, Pd-Ir bimetallic catalysts had multipoint active sites which improved the range of Pd metal state. Bimetallic catalysts had a higher conversion of VOCs than that of monometallic one. The effect of $H_2O-H_2$ pretreatment technique was the enhancement of uniform distribution of Pd particles and promotion of catalytic efficiency. In this study, addition of Ru and Ir metals to Pd promoted oxidation conversion of VOCs. In addition, $H_2O-H_2$ pretreatment promoted removal efficiency of VOCs on the $TiO_2$ support.

Effect of promoter on platinum catalyst for oxidation of VOCs (VOCs 산화반응에서 Pt 촉매에 대한 조촉매의 영향)

  • Kim, Moon-Chan;Shin, Jin-Sil
    • Analytical Science and Technology
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    • v.19 no.5
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    • pp.422-432
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    • 2006
  • The volatile organic compounds(VOCs) have been recognized as a major contributor to air pollution. The catalytic oxidation is one of the most important processes for VOCs destruction due to getting high efficiency at low temperature. In this study, monometallic Pt and bimetallic Pt-Ru, Pt-Ir were supported to ${\gamma}-Al_2O_3$. Xylene, toluene and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, XPS, TEM and BET analysis. As a result, Pt-Ru, Pt-Ir bimetallic catalysts showed higher conversion than Pt monometallic catalyst. Pt-Ir bimetallic catalyst showed the highest conversion on the ${\gamma}-Al_2O_3$ support. In the VOCs oxidation, Pt-Ru, Pt-Ir bimetallic catalyst had multipoint active sites, so it improved the range of Pt metal state. Therefore, bimetallic catalysts showed higher conversion of VOCs than monometallic ones. In this study, the use of small amount of Ru, Ir to Pt promoted oxidation conversion of VOCs.

Nanostructure Control of PtNiN/C Catalysts for Oxygen Reduction Reaction by Regulating Displacement Rate of Precursor (전구체 치환 속도 조절을 통한 산소환원반응용 PtNiN/C 촉매의 나노구조 제어)

  • Dong-gun Kim;Seongseop Kim;Sung Jong Yoo;Pil Kim
    • Clean Technology
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    • v.30 no.1
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    • pp.55-61
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    • 2024
  • Efforts are actively underway to address the issues related to the high cost of Pt-based catalysts for oxygen reduction reactions by designing high-performance Pt-based alloys through the control of their nanostructures. In this study, a method was proposed to control the nanostructure of Pt-based alloys, either hollow or core-shell, by adjusting the pH of the solution during the galvanic replacement reaction between the carbon-supported nickel-nickel nitride composite and the Pt ions. The physical characteristics, including the state, quantity, and morphology of the metal particles under different preparation conditions, were evaluated through X-ray diffraction, transmission electron microscopy, and inductively coupled plasma. When the prepared catalysts were employed for the oxygen reduction reaction, they exhibited an improvement in area specific-activity compared to a commercial Pt/C, with a 1.7 and 1.9-fold enhancement for the hollow and core-shell structured catalysts, respectively.

The influence of promoter for $CO_2$ reforming reaction by methane over Ni supported zeolite catalysts (제올라이트에 담지된 Ni 촉매상에서 메탄에 의한 이산화탄소의 개질반응에서 첨가된 조촉매의 영향)

  • 정헌도;김권일;김태환;이범석;추고연
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2002.05a
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    • pp.209-213
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    • 2002
  • 최근 들어 메탄올 환원제로 사용하는 이산화탄소의 촉매 개질 반응이 많은 주목을 받고 있다. 메탄에 의한 이산화탄소의 개질 반응 시 생성되는 합성 가스는 기존의 수증기 개질 반응에서 생성되는 합성 가스에 비하여 $H_2$/CO의 비가 낮으며 직접 메탄올 및 DME와 같은 유용한 물질로의 전환이 유리하므로 이에 대한 연구가 활발히 진행 중에 있다.(중략)

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Synthesis and characterization of 60 wt.% RGO(reduced graphite oxide) supported PtSn series catalysts for methanol electrooxidation (RGO(reduced graphite oxide)에 담지된 PtSn 시리즈 촉매의 합성 및 특성분석과 메탄올 산화 반응)

  • Choe, Seung-Mok;Kim, Won-Bae;Lee, Ju-Yeol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2013.05a
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    • pp.159-159
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    • 2013
  • 넓은 비표면적과 높은 전기전도성을 갖는 표면에 관능기가 도입된 RGO(reduced graphite oxide)를 modified Hummers method 와 thermal exfoliation 을 통해하여 합성하였으며 합성된 RGO를 PtSn alloy 촉매의 담지체로 도입하여 impregnation method를 통해 PtSn/RGO 시리즈 촉매를 합성하였다. XRD, SEM, TEM, XPS 분석을 통해 촉매의 특성을 분석하였고 methanol electrooxidation 활성을 확인하였다.

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A Study of the Diastereoselectivity of Diels-Alder Reactions on the Ce-SiO2 as Support

  • Ziarani, Ghodsi Mohammadi;Badiei, Alireza;Miralami, Azam
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.47-50
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    • 2008
  • The diastereoselectivity of Diels-Alder reactions were studied on the silica surface supported with different concentrations of cerium ion as efficient Lewis acid catalysts under solvent-free conditions. The results showed that the diastereoselectivity of reaction was highly improved in these conditions. The cerium ion was grafted on silica surface by using ion exchange method.