• 제목/요약/키워드: Ordered mesoporous carbons

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화학적 산처리가 중기공 탄소체의 수소저장거동에 미치는 영향 (Effect of Acid Treatments on Hydrogen Storage Behaviors of Ordered Mesoporous Carbons)

  • 이슬이;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.229.1-229.1
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    • 2010
  • We investigated the effect of chemical acid treatments on hydrogen storage behaviors of the ordered mesoporous carbons (MCs). The surface functional groups and specific elements of the MCs were characterized with Fourier Transform Infrared (FT-IR) spectrometry and X-ray photoelectron spectroscopy (XPS). Also, the changes in the surface functional groups of the MCs were quantitatively detected by Boehm's titration method. The structural properties of the MCs were investigated using X-ray diffraction (XRD). The hydrogen adsorption capacity of the MCs was evaluated by means of adsorption isotherms at 77 K/1 bar. The formation of surface functional groups by the acidic treatments could influence on the hydrogen storage capacity of the MCs.

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One-step synthesis of dual-transition metal substitution on ionic liquid based N-doped mesoporous carbon for oxygen reduction reaction

  • Byambasuren, Ulziidelger;Jeon, Yukwon;Altansukh, Dorjgotov;Ji, Yunseong;Shul, Yong-Gun
    • Carbon letters
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    • 제17권1호
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    • pp.53-64
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    • 2016
  • Nitrogen (N)-doped ordered mesoporous carbons (OMCs) with a dual transition metal system were synthesized as non-Pt catalysts for the ORR. The highly nitrogen doped OMCs were prepared by the precursor of ionic liquid (3-methyl-1-butylpyridine dicyanamide) for N/C species and a mesoporous silica template for the physical structure. Mostly, N-doped carbons are promoted by a single transition metal to improve catalytic activity for ORR in PEMFCs. In this study, our N-doped mesoporous carbons were promoted by the dual transition metals of iron and cobalt (Fe, Co), which were incorporated into the N-doped carbons lattice by subsequently heat treatments. All the prepared carbons were characterized by via transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). To evaluate the activities of synthesized doped carbons, linear sweep was recorded in an acidic solution to compare the ORR catalytic activities values for the use in the PEMFC system. The dual transition metal promotion improved the ORR activity compared with the single transition metal promotion, due to the increase in the quaternary nitrogen species from the structural change by the dual metals. The effect of different ratio of the dual metals into the N doped carbon were examined to evaluate the activities of the oxygen reduction reaction.

메조포어러스카본의 마그네슘 옥사이드의 처리에 따른 이산화탄소 흡착 거동 (Influence of Magnesium Oxide on Carbon Dioxide Adsorption Behaviors of Mesoporous Carbons)

  • 장동일;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.221.2-221.2
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    • 2011
  • In this study, we prepared the magnesium oxide decorated ordered mesoporous carbons processed by the reduction of magnesium oxide precursor on the CMK-3 surfaces in order to investigate the characterization and the effect on their carbon dioxide adsorption behaviors. The magnesium contents of the prepared samples were characterized using XPS. The textural properties of the prepared samples were investigated by $N_2$/77 K adsorption isotherms by BET equation. The carbon dioxide adsorption capacities of the prepared samples were investigated by the amounts of carbon dioxide adsorptions at 298 K and 1.0 atm. The results showed that the magnesium oxide on the CMK-3 surface enhanced interaction between carbon dioxide and adsorbents. Consequently, it was found that the magnesium oxide led to an increase in the carbon dioxide adsorption capacity of the CMK-3.

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Synthesis of Mesoporous Carbons with Controllable N-Content and Their Supercapacitor Properties

  • Kim, Jeong-Nam;Choi, Min-Kee;Ryoo, Ryong
    • Bulletin of the Korean Chemical Society
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    • 제29권2호
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    • pp.413-416
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    • 2008
  • A synthesis route to ordered mesoporous carbons with controllable nitrogen content has been developed for high-performance EDLC electrodes. Nitrogen-doped ordered mesoporous carbons (denoted as NMC) were prepared by carbonizing a mixture of two different carbon sources within the mesoporous silica designated by KIT-6. Furfuryl alcohol was used as a primary carbon precursor, and melamine as a nitrogen dopant. This synthesis procedure gave cubic Ia3d mesoporous carbons containing nitrogen as much as 13%. The carbon exhibited a narrow pore size distribution centered at 3-4 nm with large pore volume (0.6-1 cm3 g-1) and high specific BET surface area (700-1000 m2 g-1). Electrochemical behaviors of the NMC samples with various N-contents were investigated by a two-electrode measurement system at aqueous solutions. At low current density, the NMC exhibited markedly increasing capacitance due to the increase in the nitrogen content. This result could be attributed to the enhanced surface affinity between carbon electrode and electrolyte ions due to the hydrophilic nitrogen functional groups. At high current density conditions, the NMC samples exhibited decreasing specific capacitance against the increase in the nitrogen content. The loss of the capacitance with the N-content may be explained by high electric resistance which causes a significant IR drop at high current densities. The present results indicate that the optimal nitrogen content is required for achieving high power and high energy density simultaneously.

Synthesis of Ordered Mesoporous Manganese Oxides by Double Replication for Use as an Electrode Material

  • Guo, Xiao-Feng;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.186-190
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    • 2011
  • Periodically ordered mesoporous manganese oxides were synthesized in a single and double replication procedure. Mesoporous SBA-15 and -16 silica and their reverse replica carbons were successively used as hard templates. The silica and carbon pore systems were infiltrated with $Mn(NO_3)_2{\cdot}xH_2O$ or $Mn(AcAc)_2$, which was then converted to $Mn_2O_3$ at 873 K; the silica and carbon matrix were finally removed by NaOH solution or calcinations in air. The structure of the mesoporous $Mn_2O_3$, using a carbon template, corresponds to that of the original SBA-15 and SBA-16 silica. The products consist of hexagonally arranged cylindrical mesopores with crystalline pore walls or cubic mesoporous pores. The structure of replica has been confirmed by XRD, TEM analysis, and its electrochemical properties were tested with cyclic voltammetry. Formation of $Mn_2O_3$ inside the mesoporous carbon pore system showed much improved electrical properties.

탄소지지체의 화학적 변형에 따른 연료전지용 백금-루테늄 촉매의 전기화학적 활성의 영향 (Effect of Chemical Modification of Carbon Supports on Electrochemical Activities for Pt-Ru Catalysts of Fuel Cells)

  • 김병주;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.94.1-94.1
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    • 2011
  • In this work, ordered mesoporous carbons (OMCs) were prepared by the conventional templating method using mesoporous silica (SBA-15) for Pt-Ru catalyst supports in fuel cells. The influence of surface modification on carbon supports on the electrochemical activities of Pt-Ru/OMCs was investigated with different pH. The neutral-treated OMCs (N-OMCs), base-treated OMCs (B-OMCs), and acid-treated OMCs (A-OMCs) were prepared by treating OMCs with 2 M $C_6H_6$, 2 M KOH, and 2 M $H_3PO_4$, respectively. The surface characteristic of the carbon supports were determined X-ray photoelectron spectroscopy (XPS). The electrochemical activities of the Pt-Ru catalysts had been enhanced when the OMCs supports were treated by basic or neutral agents, while the electrochemical activities had been decayed for the A-OMCs supported Pt-Ru.

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자성에 의해 분리 가능한 메조포러스 카본의 소프트 주형 합성 (Soft-template Synthesis of Magnetically Separable Mesoporous Carbon)

  • 박성수;하창식
    • 접착 및 계면
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    • 제18권2호
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    • pp.75-81
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    • 2017
  • 본 연구에서는 잘 배열된 나노세공 구조와 자성체 나노입자를 포함하는 메조포러스 카본(Carbonized Ni-FDU-15)을 합성하였다. Carbonized Ni-FDU-15는 구조형성 주형으로 트리블럭 공중합체(F127)를 이용하고, 카본 세공벽 형성 물질로 resol 전구체를 사용하며 질산 니켈(nickel(II) nitrate)을 금속이온 원으로 사용하여 증발유도 자기조립(Evaporation-Induced Self-Assembly, EISA)과 직접 탄화과정을 거쳐서 합성되었다. 메조포러스 카본은 잘 배열된 이차원적 육방체 구조(2D-hexagonal structure)를 가진다. 한편, 세공벽 내 자성체 나노입자는 니켈(Ni) 금속과 니켈 산화물(NiO)이 생성되었다. 나노입자의 크기는 약 37 nm이었다. 그리고 Carbonized Ni-FDU-15의 표면적, 세공크기, 세공부피는 각각 $558m^2g^{-1}$, $22.5{\AA}$ 그리고 $0.5cm^3g^{-1}$이었다. Carbonized Ni-FDU-15는 외부에서 자력을 가하였을 때 자력이 가해지는 방향으로 이동함을 확인하였다. 이러한 자성체 담지 메조포러스 카본 물질은 흡착/분리, 자기 저장 매체, 자성 유체(ferrofluid), 자기 공명 영상(MRI) 및 약물 타겟팅 등의 광범위한 응용 분야에 높은 응용성을 가질 것으로 기대된다.