• 전기화학회지
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• 제12권3호
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• pp.282-286
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• 2009

MWNT(CNTs)를 지지체로 촉매를 합성하고 특성평가를 진행하였다. $Pt/Au/TiO_2$는 CNTs(cabon 나노 튜브) 탄소 지지체에 첨가되어 직접 메탄올 연료 전지의 성능을 개선하였다. XRD와 SEM을 통해 아나타제 $TiO_2$와 Pt/Au를 확인하였고 각각의 입자 사이즈는 200 nm와 20${\sim}$25 nm 이다. 혼성 촉매의 활성은 CV를 통해 측정되었으며 제조된 촉매는 연료전지 이용에 유망하다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.84.1-84.1
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• 2010

Since the discovery of the carbon nanotube(CNTs), they have attracted much attention because of unique properties that may impact many fields of science and technology. The considerable properties of CNTs include high surface area, outstanding thermal, electrical conductivity and mechanical stability. However, uniform deposition of Pt nanoparticles on carbon surface remains inaccessible territory because of the inert carbon surface. In this study, we prepared directly oriented CNTs on carbon paper as a catalyst support in cathode electrode. carbon surface was functionalized using aryl diazonium salt for increasing adhesion of Ni particles which is precursor for growing CNTs. For fabricate electrode, CNTs on carbon paper were grown by chemical vapor deposition using Ni catalyst and Pt nanoparticles were deposited on CNTs oriented carbon paper by polyol method. The performance was measured using Proton electrolyte Membrane Fuel Cell(PEMFC). The structure and morphology of the Pt nanoparticles on CNTs were characterized by Scanning electron Microscopy(SEM) and Transmission electron Microscopy (TEM). The average diameter of Pt nanoparticles was 3nm.

• Carbon letters
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• 제11권4호
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• pp.336-342
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• 2010

Different oxidation treatments on CNTs using diluted 4.0 M $H_2SO_4$ solution at room temperature and or at $90^{\circ}C$ reflux conditions were investigated to elucidate the physical and chemical changes occurring on the treated CNTs, which might have significant effects on their performance as catalyst supports in PEM fuel cells. Raman spectroscopy, X-ray diffraction and transmission electron microscope analyses were made for the acid treated CNTs to determine the particle size and distribution of the CNT-supported Pt-Ru nanoparticles. These CNT-supported Pt-based nanoparticles were then employed as anode catalysts in PEMFC to investigate their catalytic activity and single-cell performance towards $H_2$ oxidation. Based on PEMFC performance results, refluxed Pt-Ru/CNT catalysts prepared using CNTs treated at $90^{\circ}C$ for 0.5 h as anode have shown better catalytic activity and PEMFC polarization performance than those of the commercially available Pt-Ru/C catalyst from ETEK and other Pt-Ru/CNT catalysts developed using raw CNT, thus demonstrating the importance of acid treatment in improving and optimizing the surface properties of catalyst support.

• Carbon letters
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• 제25권
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• pp.55-59
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• 2018

Carbon chain inserted carbon nanotubes (CNTs) have been experimentally proven having undergone pronounced property change in terms of electrical conductivity compared with pure CNTs. This paper simulates the geometry of carbon chain inserted CNTs and analyzes the mechanism for conductivity change after insertion of carbon chain. The geometric simulation of Pt doped CNT was also implemented for comparison with the inserted one. The results indicate that both modification by Pt atom on the surface of CNT and addition of carbon chain in the channel of the tube are effective methods for transforming the electrical properties of the CNT, leading to the redistribution of electron and thereby causing the conductivity change in obtained configurations. All the calculations were obtained based on density functional theory method.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.103-106
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• 2005

In order to investigate the catalytic mechanism for the growth of carbon nanotubes (CNTs), a comprehensive study was conducted using carbon materials synthesized at 680 ${^{\circ}C}$ with a gas mixture of CO-H$_2$ after reduction at 800 ${^{\circ}C}$ by H$_2$ gas from iron oxide, and metal Pt. The resulting material was observed by scanning electron microscopy (SEM) and X-ray diffraction patterns (XRD) after a variety of reaction times. The carbon materials synthesized by metal Pt were little affected by reaction time and the sintered particles did not form CNTs. Xray analysis revealed that metal Fe was completely converted to iron carbide (Fe$_3$C) without Fe peaks in the early stage. After 5 min, iron carbide (Fe$_3$C) and carbon (C) phases were observed at the beginning of CNTs growth. It was found that the intensity of the carbon(C) peak gradually increased with the continuous growth of CNTs as reaction time increases. It was also found that the catalyst of growth of CNTs was metal carbide.

• 대한화학회지
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• 제64권1호
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• pp.49-53
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• 2020

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1090-1094
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• 2004

Studies on porous oxide electrode, dye and electrolyte for dye-sensitized solar cells have been intensively carried out until now. However, counter electrode have not been much studied so far. Accordingly, it is needed to investigate new counter electrode materials with superior catalyst property and to substitute for Pt electrode. In this case, carbon nano-tubes (CNTs) are one of alternatives for counter electrodes as following merits: low resistivity, excellent electron emission property, large surface area and low cost due to development of mass production technique. Such advantages gave us to select multiwalled CNTs (MWCNT) as counter electrode for dye-sensitized solar cell. Also, cyclic voltammetry and impedance spectroscopy were used to investigate electrochemical properties of both CNT electrode and Pt electrode. It was found that sheet resistance of CNT electrode was similar to that of Pt electrode, also, electrochemical properties of CNT electrode was superior to that of Pt electrode on the basis on the measurement of CV and impedance spectrum. It was found that CNT is likely to be a very promising electrode material for dye solar cells.

• Carbon letters
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• 제10권3호
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• pp.213-216
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• 2009

The electrochemical deposition of Pt nanoparticles on carbon nanotubes (CNTs) supports and their catalytic activities for methanol electro-oxidation were investigated. Pt catalysts of 4~12 nm average crystalline size were grown on supports by potential cycling methods. Electro-plating of 12 min time by potential cycling method was sufficient to obtain small crystalline size 4.5 nm particles, showing a good electrochemical activity. The catalysts' loading contents were enhanced by increasing the deposition time. The crystalline sizes and morphology of the Pt/support catalysts were evaluated using X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The electrochemical behaviors of the Pt/support catalysts were investigated according to their characteristic current-potential curves in a methanol solution. In the result, the electrochemical activity increased with increased plating time, reaching the maximum at 12 min, and then decreased. The enhanced electroactivity for catalysts was correlated to the crystalline size and dispersion state of the catalysts.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1973-1978
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• 2014

Here, we present a facile method to synthesize Pt nanoparticles (NPs) and graphene composite materials (Pt/G) via vacuum filtration. Anodic aluminum oxide (AAO) templates were used to separate Pt/G composite and liquid phase. This method can be used to easily tune the mass ratio of Pt NPs and graphene. Pt NPs, graphene, and carbon nanotubes (CNTs) as building blocks were characterized by a variety of techniques such as scanning electron microscopy, UV-Vis spectroscopy, and Raman spectroscopy. We compared the electrocatalytic activities of Pt/G with Pt NP and CNT films (Pt/CNT) by cyclic voltammetry (CV), CO oxidation, and methanol oxidation. Pt/G was much more stable than pure Pt films. Also, Pt/G had better electrochemical activity, CO tolerance and methanol oxidation than Pt/CNT loaded with the same amount of Pt NPs due to the better dispersion of Pt NPs on graphene flakes without aggregation. We further synthesized Au@Pt disk/G and Pt nanorods/G to determine if our synthetic method can be applied to other NP shapes such as nanodisks and nanorods, for further electrocatalysis studies.

• Korean Chemical Engineering Research
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• 제49권5호
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• pp.644-651
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• 2011

향후 도래할 수소경제에서 가장 유망한 기술 중에 하나인 고체수소저장 시스템들의 전체성능은 고체수소화물 내부의 열 및 물질전달 속도에 크게 영향을 받으며, 최적화된 시스템 설계를 위해서 이들에 대한 연구들이 선행되어야 한다. 본 연구에서는 Pt-CNTs 수소저장물질을 이용한 수소저장시스템에 대한 모델링 및 2차원 비정상상태 전산해석을 수행하였다. 기존 상용화된 CFD 소프트웨어를 이용하여 충전동안 발생하는 열 및 물질전달에 대한 현상들을 연구하였으며, 최적화된 수소저장시스템 설계는 고압에서 대류에 의한 냉각효과를 최대화하여 시스템 내부의 온도 상승과 충전시간 지연을 개선할 수 있음을 밝혀냈다. 아직까지 CNT 기반의 수소저장시스템에 대한 연구들이 보고되고 있지 않은 상황에서, 본 연구는 향후 CNT 기반의 고체수소저장시스템 최적 설계에 대한 방안들을 제시한다.