• Transactions of the Korean hydrogen and new energy society
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• v.24 no.5
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• pp.359-366
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• 2013

This work is investigated for the catalytic decomposition of hydrogen iodide (HI). Platinum was used as active material by loading on $ZrO_2-SiO_2$ mixed oxide in HI decomposition reaction. To obtain high and stable conversion of hydrogen iodide in severe condition, it was required to improve catalytic activity. For this reason, a method increasing dispersion of platinum was proposed in this study. In order to get high dispersion of platinum, zirconia was incorporated in silica by sol-gel synthesis. Incorporating zirconia influence increasing platinum dispersion and BET surface area as well as decreasing deactivation of catalysts. It should be able to stably product hydrogen for a long time because of inhibitive deactivation. HI decomposition reaction was carried out under the condition of $450^{\circ}C$ and 1 atm in a fixed bed reactor. Catalysts analysis methods such as $N_2$ adsorption/desorption analysis, X-ray diffraction, X-ray fluorescence, ICP-AES and CO gas chemisorption were used to measurement of their physico-chemical properties.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.543-549
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• 1997

The direct reaction of carbon dioxide($CO_2$) with butane($C_4H_{10}$) to obtain synthesis gas and hydrocarbon compounds have been studied on nickel loaded catalysts. In the reaction of $CO_2$ with $C_4H_{10}$, Ni loaded catalysts showed similar activity with Pt catalyst and Coke deposition on the catalyst was severe by dehydrogenation of butane. The main products were carbon monoxide and hydrogen, when alumina and Y type zeolite were used as a support. Instead, a great deal of aromatic hydrocarbons were obtained on the Ni loaded ZSM-5 catalyst. The conversion of $CO_2$ increased with the increasing molar ratio of $CO_2$/$C_4H_{10}$ on Ni/ZSM-5, Ni/NaY and Ni/alumina catalyst, but the conversion decreased again from the ratio of 2. The value of $CO_2$ conversion was the highest at the 5wt% of Ni loading on ZSM-5 catalyst. A part of cokes deposited on the catalysts diminished when only $CO_2$ gas or water steam flowed into the reactor. The coke deposited on the catalysts was very reactive and it may be an important intermediate for the carbon dioxide reforming reaction.

• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.197-201
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• 2014

As the importance of rare metal is increasing globally, Japan introduced the concept of Strategic Elements in 2004, and started Strategic Elements Project in 2007. The Goal of this project run by MEXT (Ministry of Education, Culture, Sports, Science and Technology) is to develop high-function materials and components that do not use rare or harmful elements by studying the role and characteristics of the elements that compose materials and components and decide their functions and characteristics. In September 2010, Japanese coast guard arrested a Chinese fishing boat near Senkaku Islands (Diaoyudao Islands by China), which escalated to the territory issue and eventually a big diplomatic and economic conflict. In order to put pressure on Japanese Government, China used an economic option, which is the ban of rare earth export to Japan. This incident doubled Japan's motivation to develop Strategic Elements and put more efforts into this Project. MEXT set the following three research areas in February 2012: Study of alternative materials using sufficient and harmless elements, Study of applications for the high-functions of Strategic Elements, Study of practical design for components using Strategic Elements. Through a course of gathering the opinion of professionals, MEXT settled down with the following 4 research and study areas for the Strategic Elements Project in June 2012. 1. Magnetic materials to replace Dy, Nd. 2. Catalyst/Battery materials to replace Pt, Rh/Li, Co. 3. Electronic materials to replace In, Ta. 4. Structural materials to replace Nb, Mo. This paper deals with the first area and reviews the results of the research and study as of now.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.587-593
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• 2023

This research project focused on the production of hydrogen through ammonia decomposition reactions while investigating how the reactivity of this process varies when employing different catalysts. Several metal oxide supports (Al₂O₃, La₂O₃, CeO₂) were utilized as catalysts, with active metals from both the transition metal group (Co, Ni, Fe, Cr, Cu) and the noble metal group (Ru, Rh, Pd, Pt) impregnated onto these supports. Furthermore, the study examined how the reactivity evolves with changes in reaction temperature when employing the prepared catalysts. Additionally, the research delved into the distinctive activation energies associated with each of the catalysts. In this research, In the noble metal catalyst system, the order of high activity for ammonia decomposition reaction to produce hydrogen is Ru > Rh > Pt ≈ Pd. In the transition metal catalyst system, the order of high activity is Co > Ni > Fe > Cr > Cu.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.150-150
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• 2012

본 연구는 1차원 나노 구조의 합성과 기초적 분석에 관한 연구로써 특히 무기 산화물 나노재료를 그 대상으로 하였다. 내용으로는 첫째, 1차원 코어 나노와이어의 합성을 하였고 Thermal evaporation, substrate의 가열, 그리고 MOCVD 를 사용한 결과들을 나열한다. 둘째, 코어-쉘 나노와이어를 제작하기 위하여 특히 쉘층의 제작방법을 연구하였는데 PECVD, ALD, 그리고 sputtering에 의한 결과들을 나열하고 간단히 설명한다. Thermal evaporation에 의한 1차원 나노와이어 합성의 경우는 MgO의 예를 들었는데 MgO 나노와이어는 Au가 증착된 기판을 열처리하여 Au dot를 형성하고 이의 morphology를 조절하여 최적의 나노와이어 합성조건을 선정하였다. 이로써 기판 morphology가 나노선의 성장및 형상에 영향을 준다는 사실을 알게 되었다. 이 사실은 In2O3기판을 사용하고 이의 표면거칠기를 열처리로 조절하므로써 역시 나노와이어의 성장을 촉진하는 방법을 찾아내었다. 또한 thermal evaporation공법은 source분말의 선택에 따라 다양한 소재를 제작가능하다는 결과를 제시하였다. 예를 들면 SiOx 층이 precoating된 chamber내에서 MgO 나노선을 합성하는 것과 동일한 조건으로 실험을 진행하면 Mg2SiO4 나노와이어가 형성된 것을 확인하였다. 또한 Sn과 MgB2 분말을 함께 적용할 경우 Sn tip을 가진 MgO 나노와이어를 얻을 수 있었다. 이는 Sn이 동시에 촉매의 역할을 하였기 때문일 것으로 추정된다. 한편 Sn과 Bi 혼합분말을 적용한 경우 Bi2Sn2O7 신소재 tip을 포함한 SnO2 나노와이어를 얻을 수 있었다. 이 경우 Bi원자가 적절한 촉매의 역할을 수행한 것으로 사료된다. Substrate의 가열공법에서는 Si wafer상에 각종 금속 즉 Au, Ag, Cu, Co, Mo, W, Pt, Pd등 초박막을 DC sputter 로 형성한후 annealing하는 기술을 사용하였다. 특기할 만한 것은 Co를 사용한 경우 나노와이어의 spring구조를 얻을 수 있었다는 점이다. MOCVD에 의하여는 Ga2O3및 Bi2O3 나노와이어를 비교적 저온에서 합성하였고 In2O3의 경우는 독특한 나노구조를 형성하였고 이의 결정학적 특성에 대하여 조사하였다.

• Journal of Adhesion and Interface
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• v.16 no.4
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• pp.152-155
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• 2015

Platinum (Pt) is an easily moldable, anti-corrosive and also good catalyst in a variety of chemical reactions. Platinum can be used in many fields, however, however, the low wettability of platinum substrate in many platinum-based devices has been made a problem when they contact with liquid state environment. In this study, we report a simple and effective self-assembled monolayer coating method which provides tremendously increased wettability on platinum substrate device by using Sodium 3-mercapto-1-propanesulfonic acid solution. After surface modifications, water contact angle of the surfaces displayed less than $10^{\circ}$, representing that surfaces are successfully coated to be super-hydrophilic surface by simple dip coating method.