• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.86.2-86.2
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• 2011

저온형 연료전지인 직접 메탄올 연료전지(Direct Methanol Fuel Cells, DMFC)는 친환경적인 발전 시스템, 높은 에너지 효율의 장점 때문에 주목을 받고 있으나 연료극의 촉매로 사용되는 금속은 고가의 귀금속인 Pt와 Ru가 요구되어 제조비용이 비싸기 때문에 촉매의 양을 줄이고, 반응 도중 생성되는 CO에 의한 촉매의 피독 문제 등 해결하여야 할 점이 산적해 있어 연료전지 중 촉매의 활성을 높이는 연구들이 활발히 이루어지고 있다. 종래의 MEA의 촉매층 제조공정은 우선 환원석출법에 의해 Pt-Ru/C를 합성하고 Nafion 용액에 혼합하여 Pt-Ru/C 슬러리를 제조한다. 이 방법에서는 carbon sheet에 spray 방법으로 Pt-Ru/C 촉매층이 만들어지기 때문에, Pt-Ru 촉매가 Nafion에 의해 부분적으로 매몰되어 촉매의 전기화학적 활성이 떨어지는 문제점이 있다. 이를 해결하는 방안으로 펄스전류를 이용하여 Pt-Ru 합금입자를 carbon sheet에 전기화학적으로 담지 시켜 Nafion에 매몰되는 것을 방지하는 펄스전해법 연구가 진행되고 있다. 그러나 촉매의 입자크기가 일반적으로 50~70 nm 이상으 크기 때문에 촉매의 낮은 활성이 문제점으로 야기되고 있다. 본 연구에서는 Pt-Ru/C 촉매층 제조 문제점을 해결하고, 촉매의 전기화학적 활성을 증가시키기 위해서 2~4 nm Pt-Ru 콜로이드를 전해액으로 사용하고, 전기영동법을 이용하여 Pt-Ru 나노 입자를 carbon sheet($1{\times}1cm^2$) 에 담지 시켰다. 전기영동법에서 균일한 Pt-Ru 촉매층의 제조를 위해 전류인가 방법으로는 펄스전류를 사용하였고, 실험변수로는 전해액 pH, duty cycle, 담지시간을 선정하였다. 합성된 Pt-Ru 콜로이드를 TEM분석으로 나노입자의 크기와 분산성 분석하였고, 콜로이드 나노입자의 표면전하 상태를 분석하기 위해 zeta-potential을 분석하였다. Pt-Ru/C의 촉매의 전기화학적 활성을 분석하기 위하여 0.5 M H_2SO_4$ 와 1 M $CH_3OH$ 혼합용액에 CV(Cyclic Voltammetry)실시하였고, carbon sheet 전극 상 Pt-Ru의 분산성 확인을 위하여 FE-SEM분석을 수행하였다.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.364-369
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• 2013

Oxidative dehydrogenation of n-butane over mesoporous Cr catalysts were studied. Catalysts were prepared by Cr impregnated method over Ti or Zr dispersed mesoporous support such as SBA-15, ${\gamma}$-alumina and characterized by XRD, SEM, TEM, FT-IR UV-Vis and ICP-AES. The effect of high surface area was not noticed appreciably in terms of conversion, but for Cr catalysts with Ti and Zr-incorporated on SBA-15 and ${\gamma}$-alumina. showed high selectivity of trans-2-butene.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.139-148
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• 1994

The partial oxidation of methane with nitrous oxide on silica-supported metal-oxygen cluster compounds, known as heteropoly acids, has been studied. The effects of several variables such as reaction temperature, partial pressure of reactants, residence time, loading of the catalysts, and pretreatment temperature, on the conversion and product distribution were observed. The kinetics also has been studied. The conversion and yield of formaledehyde show maximum values at a loading of 20 wt%. The apparent reaction order of methane conversion is ca. 1.0 with respect to $CH_4$ and ca. 0.4 with respect to $N_2O$. In addition, the apparent activation energy is 30.78 kcal/mole. The addition of small quantities methane whereas water introduced to the reactant decreased the activity of catalyst under present study.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.397-400
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• 2015

The effects of surface treatment method of unreacted N-[3-(trimethoxysilyl)propyl]ethylenediamine (2NS), $N^1$-(3-trimethoxysilylpropyl)diethylenetriamine (3NS), and 3-cyanopropyltriethoxysilane (1NCy) after grafting on the surface of silica and of the surface treatment temperature on ethylene polymerization were investigated. The Zr content of supported catalyst employing filtering method was higher than that of washing method, and the activities of supported catalysts prepared by washing method were higher than those of filtering methods significantly. Regardless of surface treatment methods the activities were in order by $SiO_2/2NS/(n-BuCp)_2ZrCl_2>SiO_2/1NCy/(n-BuCp)_2ZrCl_2>SiO_2/3NS/(n-BuCp)_2ZrCl_2$. The ethylene polymerization activity was increased as the surface treatment temperature of aminosilane on silica increased.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.268-269
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• 2014

나노입자 담지 탄소소재는 촉매재료로써 다양하게 응용되고 있으며, 이들 재료의 공정수를 획기적으로 줄이고자 솔루션 플라즈마라는 새로운 공정을 이용하여 One-Step으로 합성하는데 성공하였다. 합성된 재료의 경우 1~3nm의 미세한 나노입자가 탄소소재위에 균일하게 분산되어 있는 것을 확인 할 수 있었고, 촉매 활성 역시 매우 뛰어남을 확인 할 수 있었다.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.256-264
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• 1999

The performance of the Pt-B/cordierite catalysts (2 wt%) Pt, 70 wt% Alumina, 28 wt%) Ceria and Zirconia, B: base metal) loaded with 6∼12 wt% Mn, Cu, V, Co, Cr and Ba, respectively was studied for partial oxidation of methane reaction and compared with that of Ni loaded catalyst. As a results, it was found that Ba, Co, Cr as well as Ni loaded catalysts showed higher activity for methane partial oxidation of methane than the Mn, Cu and V loaded catalyst. But it was known that catalysts having good activity for methane showed the good activity for coke formation, too. A XRD analysis of the catalyst before and after the reaction using 5 wt% Ni/Al$_2$O$_3$) showed that there were three Ni phases. In these results, it was found that methane oxidation reaction occulted at the front of the catalyst bed consisted of NiAl$_2$O$_4$and NiO and reforming reaction occurred at the rear part of the catalyst bed consisted of reduced Ni.

• Journal of Energy Engineering
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• v.2 no.2
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• pp.194-199
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• 1993

Gas diffusion passes are introduced to catalyst layer so as to enlarge reaction region in cathode and anode and then improve electrode performances. The catalyst layer was manufactured with PTFE/carbon (none catalyst loaded) for gas diffusion and Pt/carbon (10 w/o Pt catalyst loaded) by varing the mixing ratio of (PTFE/carbon) to (Pt/carbon) by catalyst powdering method. The electrodes made by mixing Pt(10 w/o)/carbon powders and PTFE/carbon powders containing 60 w/o PTFE at the ratio of 7 : 3 showed the best electrode performances. It was known that by comparing the porosities to electrode performances the electrode performances were increased as both macro pore for gas diffusion and micro pore for electrolyte intrusion were formed much more. The platinum catalyst content in electrode was 0.2 mg/$\textrm{cm}^2$ and the PTFE content was 42 w/o. The electrode performance in unit cell was 220 ㎃/$\textrm{cm}^2$/0.7 V at operating temperature of 150$^{\circ}C$.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.323-327
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• 2011

A zeolite sheet (ceramic paper containing zeolite) made in a cylindrical configuration can be applied to a honeycomb rotor for the effective VOC removal. In this study, the zeolite sheet containing ZSM-5 was used as a support for Pt-loading, and its catalytic activity for the toluene combustion reaction was compared with those of the other Pt catalysts loaded on ${\gamma}-Al_2O_3$ and cordierite honeycomb. Pt/zeolite sheet catalyst showed a higher activity for toluene combustion reaction than that of $Pt/{\gamma}-Al_2O_3$ or Pt/cordierite honeycomb. On the other hand, the dispersion of Pt particles loaded on the zeolite sheet was improved by the pretreatment with $NH_3-H_2O$ vapor at room temperature. Consequently, the pretreatment of Pt/zeolite sheet by $NH_3-H_2O$ vapor significantly enhanced the catalytic activation for toluene combustion reaction.

• Bulletin of Korea Environmental Preservation Association
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• v.16 no.11
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• pp.60-63
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• 1994

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1579-1584
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• 2015

In photocatalytic reaction, the doping of metal matter can alter the titania surface properties. As such the metal matter can increase the rate of the reaction. The influence of metal doping and calcination condition of $TiO_2$ photocatalyst was investigated at the batch-type photoreactor. Several metal matters were doped to the $TiO_2$ catalyst to improve photodegradation efficiency. During the experiments, water content was 3wt%, and reactor temperature was $40^{\circ}C$. Palladium-doped $TiO_2$ was found to be the best, where as platinum or tungsten-added also showed good results. Additional doping of platinum or tungsten on Pd/$TiO_2$ had no increase on the removal efficiency. To obtain proper calcination condition, various experiments about calcination temperature and time were carried out. As a result, the optimum calcination condition was temperature of $400^{\circ}C$, time of 1 hour.