• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.692-700
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• 1993

Corrosivities and catalytic activities of platinum-transition metal alloy catalyses loaded on carbon substrate and were studied by electrochemical method using a unit cell. And the analysis of Pt-alloy catalyst was conducted by x-ray diffractometer. Among the catalysts, the Pt-Mo/carbon, Pt-Fe-Co/carbon and Pt-Fe/carbon catalyst showed more excellent cathodic current densities than others. It was found that most of cathodic current density for the Pt-Mo/carbon electrode was $120mA/cm^2$. The current density of the Pt-Fe-Co/carbon was much higher than that of Pt/carbon, reaching $200mA/cm^2$.

• Journal of the Korean Ceramic Society
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• v.41 no.12 s.271
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• pp.880-883
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• 2004

Carbon nanofibers could be selectively formed at the groove area of the MgO substrate using microwave plasma-enhanced chemical vapor deposition system. Iridium metal was used as a catalyst layer for the formation of the carbon nanofibers. The growth direction of the carbon nanofibers was vertical to the substrate surface. The selectively grown iridium-catalyzed carbon nanofibers show around $1.8V/{\mu}m$ turn-on voltage and $1.0\;mA/cm^2$ field emission current density at $2.65\;V/{\mu}m$ in the field emission measurement.

• Carbon letters
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• v.3 no.1
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• pp.25-32
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• 2002

Aligned multi-wall carbon nanotubes (MWNTs) were synthesized through the catalytic decomposition of hydrocarbons in a quartz tube reactor. In this study, we investigated the influence of reaction parameters such as gas flow rate, ferrocene-xylene ratio and partial pressure, and reaction time on the yield and structure of vertically aligned carbon nanotubes produced by the floating catalyst method. The MWNTs produced had diameters in the range of 20~l00 nm, length around $100{\mu}m$ and bulk density about $0.51g/cm^3$ at a pressure of l0000 psi. It was possible to produce MWNTs with much faster growth rate of $12{\mu}m/min$ than that reported previously by the increase of ferrocene-xylene partial pressure.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.81-85
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• 2007

A fluidized bed reactor is made with quartz. The size of FBR is 0.055 m I.D. and 1.0 m in height. The FBR was employed for the thermocatalytic decomposition of propane to produce hydrogen without $CO_{2}$. The fluidized bed was proposed for the continuous withdraw of product carbons from the reactor. Carbon black DCC-N330 is used to decompose the propane gas. The propane decomposition reaction over carbon black catalyst in a fluidized bed reactor was carried out the temperature range of 600 ${\sim}$ 800 $^{\circ}C$, propane gas velocity of 1.0 ${\sim}$ 4.0$U_{mf}$($1U_{mf}$ = 0.61cm/s) and the catalyst loading of 100 ${\sim}$ 200g. Production of $H_{2}$ such as other reaction temperature, gas velocity, catalytic loading on the reaction rates was investigated. The carbon depositied on the catalyst surface was observed by FE-SEM. The particle size of the carbon black was observed by Particle size analyzer. Resulting production in the experiment was not only hydrogen but also several by-products such as methane, ethylene, ethane, and propylene.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.2
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• pp.162-172
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• 2008

We studied the effect of an Al underlayer on the growth of carbon nanotubes (CNTs) and their field emission characteristics, First of all, CNTs were grown on the Invar catalyst layers with different thickness of 1 to 10 nm, showing that the CNT length was saturated for the catalyst 5 nm or thicker. The CNTs grown on the 5-nm-thick catalyst were ${\sim}10{\mu}m$ long and ${\sim}30nm$ in diameter. Second, an Al underlayer was applied between the catalyst layer and the Ti diffusion barrier to reduce the diameters of CNTs for better field emission properties by forming spherical Al oxide particles on which smaller catalyst nanoparticles would occur. The optimal thickness of an Al underlayer underneath the 5-nm-thick catalyst was ${\sim}15nm$, producing the CNTs with the length of ${\sim}15{\mu}m$ and the diameter of ${\sim}15nm$. The field emission measurements, following the tape activation, showed that the thinner and longer CNTs gave rise to better field emission performance with the lower turn-on and threshold electric fields.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2961-2965
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• 2012

Mesoporous carbons with tailored pore size were prepared by using sucrose as the carbon source and silicas as the templates. The silica templates were obtained from a hydroxypropyl-${\beta}$-cyclodextrin-silica hybrids using ammonium perchlorate oxidation at different temperatures to remove the organic matter. The structures and surface chemistry properties of these carbon materials were characterized by $N_2$ adsorption, TEM, SEM and FTIR measurements. The catalytic performances of these carbon materials were investigated through the reduction of nitroaromatic using hydrazine hydrate as the reducing agent. Compared with other carbon materials, such as active carbon, and carbon materials from the silica templates obtained by using calcination to remove the organic matter, these carbon materials exhibited much higher catalytic activity, no obvious deactivation was observed after recycling the catalyst four times. Higher surface area and pore volume, and the presence of abundant surface oxygen-containing functional groups, which originate from the special preparation process of carbon material, are likely responsible for the high catalytic property of these mesoporous carbon materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.201-202
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• 2003

We developed a novel growth method of aligned carbon nanotubes. Aligned carbon nanotubes are grown on a metal catalyst on a glass substrate using biased Helicon plasma chemical vapor deposition (HPECVD) of $CH_4/H_2$ gases from 400 C to 500 C. The Helicon plasma source is one of the high-density plasma sources and is promising for low temperature carbon deposition. A Ni film was used as a catalyst to reduce the activation energy of the nanotubes' growth. The carbon nanotubes were deposited on the nickel catalysis layer selectively.

• Journal of Powder Materials
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• v.12 no.2 s.49
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• pp.117-121
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• 2005

Platinum catalysts for the DMFC (Direct Methanol Fuel Cell) were impregnated on several carbon supports and their catalytic activities were evaluated with cyclic voltammograms of methanol electro-oxidation. To increase the activities of the Pt/C catalyst, carbon supports with high electric conductivity such as mesoporous carbon, carbon nanofiber, and carbon nanotube were employed. The Pt/e-CNF (etched carbon nanofiber) catalyst showed higher maximum current density of $70 mA cm^{-2}$ and lower on-set voltage of 0.54 V vs. NHE than the Pt/Vulcan XC-72 in methanol oxidation. Although the carbon named by CNT (carbon nanotube) series turned out to have larger BET surface area than the carbon named by CNF (carbon nanofiber) series, the Pt catalysts supported on the CNT series were less active than those on the CNF series due to their lower electric conductivity and lower availability of pores for Pt loading. Considering that the BET surface area and electric conductivity of the e-CNF were similar to those of the Vulcan XC-72, smaller Pt particle size of the Pt/e-CNF catalyst and stronger metal-support interaction were believed to be the main reason for its higher catalytic activity.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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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.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.1
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• pp.57-72
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• 1990

The oxidation of carbon monoxide on a catalyst, $LaSrNiCoO_3$ was investigatigated with a plug flow system. Kinetic quantities such as reaction-rate, reaction order and Arhenius-parameters at various reactor temperature from 200$^\circ$C to 300$^\circ$C were determined. Also, the optimum condition for the oxidation of carbon monoxide with this catalyst was determined and are as follows. Partial pressure of oxigen ; 428mmHg Partial pressure of carbon monoxide ; 332mmHg Mixed moral ratio of oxigen and Carbon monoxide ; 1.3 : 1 Total gas flow ; 224ml/min Reaction temperature ; 340$^\circ$C The reaction kinetic equation at the optimum condition, temperature range from 200$^\circ$C to 340$^\circ$C, are as follow. $$ $v = Ae^{6.5Kcal/RT} [CO]^{0.93 \sim 0.98} [O_2]^{0.42 \sim 0.50}$ $$ In addition to this, numerical calculation were performed to evaluate the mass and heat transfer effect on this system.