• 한국산학기술학회논문지
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• 제7권4호
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• pp.715-720
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• 2006

CO와 유사한 분자궤도함수를 갖는 isocyanide 리간드가 포함된$Cp(CO)_{2}(L)MH$ (L = t-butylisocyanide and 2,6-dimethylphenylisocyanide M = Mo and W)를 합성하고, 이 착물과 triflic acid를 사용하여 카르보닐기를 알코올로 전환시키는 실험을 하였다. 또한, 이들 착물을 촉매 전구체로 이용하여 3-pentanone의 수소화 반응을 온화한 조건 ($23^{\circ}C,\;<4.1\;atm H_{2}$)에서 수행하였다. 촉매 활성은 매우 낮았으며, [$Cp(CO)_{2}(ArNC)Mo][BA_{r}^{F}_{4}$]의 경우에 2 turnovers/day의 결과를 나타내었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.69-75
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• 1999

The characteristics of $H_2$ gas detection have been investigated using the Pt-MIS capacitor composed of the LPCVD nitride on the oxide. The flat band voltage shift is measured as 0.1 V in 1,000 ppm $H_2$ gas ambient and to be independent of Pt catalyst thickness. It is found that the flatband voltage shift is proportional to the hydrogen concentrations. The response and recovery time of Pt-MIS capacitor are 5 mins and 25 mins respectively. The samples of 30nm thick Pt revealed much higher sensitivity than that of 150nm samples. The samples of 150nm Pt showed that the flatband voltage shift of the device is due to the formation of the dipole layer of the adsorbed hydrogen atoms at the Pt-insulator interface.

• 한국광물학회지
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• 제20권3호
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• pp.155-163
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• 2007

국내의 실리카 광물인 규질이암으로부터 실리콘알콕사이드와 같은 실리콘 유기화합물을 합성하였다. 이 실험에서는 알카리금속염 촉매 존재 하에서 트리에탄올아민과 규질이암의 반응에 의해 트리에탄올아민의 치환체인 트리스실라트라닐옥시에틸아민의 합성이 관찰되었다. 이 트리스실라트 라닐옥시에틸아민은 산성촉매인 발연황산의 존재 하에서 메탄올과의 반응으로 메톡시실란을 얻을수가 있었으며, 이 메톡시실란과 메탄올과의반응으로 테트라메톡시실란이 합성되었다. 반응의 중간 생성물 및 최종 산물은 FT-IR, XRD, SEM, 1H and 13C NMR 및 가스크로마토그래피에 의해 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3261-3266
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• 2014

A pellet of polycrystalline $CuGaO_2$ with a delafossite structure was prepared from $Ga_2O_3$ and CuO by high-temperature solid-state synthesis. The $CuGaO_2$ pellet was a p-type semiconductor for which the electrical conductivity, carrier density, carrier mobility and Seebeck coefficient were $5.34{\times}10^{-2}{\Omega}^{-1}cm^{-1}$, $3.5{\times}10^{20}cm^{-3}$, $9.5{\times}10^{-4}cm^2V^{-1}s^{-1}$ at room temperature, and $+360{\mu}V/K$, respectively. It also exhibited two optical transitions at about 2.7 and 3.6 eV. The photoelectrochemical properties of the $CuGaO_2$ pellet electrode were investigated in aqueous electrolyte solutions. The flat-band potential of this electrode, determined using a Mott-Schottky plot, was +0.18 V vs SCE at pH 4.8 and followed the Nernst equation with respect to pH. Under UV light illumination, a cathodic photocurrent developed, and molecular hydrogen simultaneously evolved on the surface of the electrode due to the direct reduction of water without deposition of any metal catalyst.

• Carbon letters
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• 제12권4호
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• pp.185-193
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• 2011

Carbon nanotubes (CNTs) have developed into one of the most competitively researched nano-materials of this decade because of their structural uniqueness and excellent physical properties such as nanoscale one dimensionality, high aspect ratio, high mechanical strength, thermal conductivity and excellent electrical conductivity. Mass production and structure control of CNTs are key factors for a feasible CNT industry. Water and ethanol vapor enhance the catalytic activity for massive growth of vertically aligned CNTs. A shower system for gas flow improves the growth of vertically aligned single walled CNTs (SWCNTs) by controlling the gas flow direction. Delivery of gases from the top of the nanotubes enables direct and precise supply of carbon source and water vapor to the catalysts. High quality vertically aligned SWCNTs synthesized using plasma enhance the chemical vapor deposition technique on substrate with suitable metal catalyst particles. This review provides an introduction to the concept of the growth of vertically aligned SWCNTs and covers advanced topics on the controlled synthesis of vertically aligned SWCNTs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.472-477
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• 2001

Spent catalysts containing platinum were generated in petroleum refinery and other chemical industries. The reclamation of precious metals from such wastes has long been attempted in view of their rare, expensive and indispensable nature. In this study, the recovery of platinum from petroleum catalysts was attempted by a method consisting mainly of dissolving alumina substrate with sulfuric acid thereby concentrating insoluble platinum. Also, platinum dissolved partially in sulfuric acid was recovered by a cementation method using aluminum metal as a reductive agent. The effect of temperature, time, concentration of sulfuric acid. and pulp density on the dissolution of substrate was investigated. When the substrate of platinum catalyst was ${\gamma}$-AI$_2$O$_3$ about 95% alumina was dissolved in 6.0M sulfuric acid at 10$0^{\circ}C$ for 2 hours. When the substrate was the mixture of ${\gamma}$-A1$_2$O$_3$and $\alpha$-A1$_2$O$_3$about 92% was dissolved after 4 hours. As a result, more than 99% of platinum could be recovered by this method and aluminum sulfate was obtained as byproduct.

• Journal of Electrochemical Science and Technology
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• 제9권3호
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• pp.212-219
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• 2018

Perovskite type ceramic membranes which exhibit dual ion conduction (proton and oxygen ion conduction) can permeate water and can aid solving operational problems such as temperature gradient and carbon deposition associated with a working solid oxide fuel cell. From this point of view, it is crucial to reveal water transport mechanism and especially the nature of the surface sites that is necessary for water incorporation and evolution. $BaCe_{0.8}Y_{0.2}O_{3-{\alpha}}$ (BCY20) was used as a model proton and oxygen ion conducting membrane in this work. Four different catalytically modified membrane configurations were used for the investigations and water flux was measured as a function of temperature. In addition, CO was introduced to the permeate side in order to test the stability of membrane against water and $CO/CO_2$ and post operation analysis of used membranes were carried out. The results revealed that water incorporation occurs on any exposed electrolyte surface. However, the magnitude of water permeation changes depending on which membrane surface is catalytically modified. The platinum increases the water flux on the feed side whilst it decreases the flux on the permeate side. Water flux measurements suggest that platinum can block water permeation on the permeate side by reducing the access to the lattice oxygen in the surface layer.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.292-300
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• 2006

In order to improve energy efficiency in the dilute trichloroethylene removal using the nonthermal plasma process, the barrier discharge treatment combined with manganese dioxide was experimentally studied. Reaction kinetics in this process was studied on the basis of final byproducts distribution. Decomposition efficiency was improved to about $99\;\%$ at the specific energy of 40 J/L with passing through manganese dioxide. C=C ${\pi}$ bond cleavage of TCE substances gave DCAC, which has the single bond of C-C through oxidation reaction during the barrier discharge plasma treatment. Those DCAC were broken easily in the subsequent catalytic reaction due to the weak bonding energy about $3{\sim}4\;eV$ compared with the double bonding energy in TCE molecules. Oxidation byproducts of DCAC and TCAA from TCE decomposition are generated from the barrier discharge plasma treatment and catalytic surface chemical reaction, respectively. Complete oxidation of TCE into COx is required to about 400 J/L, but $CO_2$ selectivity remains about $60\;\%$.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.415-418
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• 2008

This paper presents an innovative prototype of a new conceptual electromagnetic induction-based fluid beating appliance using voltage-fed type scries capacitor-compensated load resonant high-frequency IGBT inverter with a phase-shifted PWM and a power factor correction schemes. Its operating characteristics in steady-state are illustrated including unique features and evaluated on the basis of its computer simulation and experimental results of 10kw breadboard appliance for hot water producer and superheated steamer. The promising cost effective inverter-fed boiler appliances for electromagnetic induction-heated type fluid-heating in the pipeline systems are proposed for induction-heated boiler, super heat steamer, high temperature water producer, hot gas producer and metal catalyst heating for exhaust gas cleaning in engine, which are more suitable and acceptable for industrial, chemical, and consumer energy utilization for household and business from a practical point of view.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.328.2-328.2
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• 2014

Semiconductor nanowires (NWs) have attracted research interests due to the distinct physical properties that can lead to variousoptical and electrical applications. In this paper, we have grown InAs NWs viagold (Au)-assisted vapor-liquid-solid (VLS) and catalyst-free vapor-solid (VS) mechanisms and investigated on the p-type doping profile of the NWs. Metal-organic chemical vapor deposition (MOCVD) is used for the growth of the NWs. Trimethylindium (TMIn) and arsine (AsH3) were used for the precursor and diethyl zinc (DEZn) was used for the p-type doping source of the NWs. The effectiveness of p-type doping was confirmed by electrical measurement, showing an increase of the electron density with the DEZn flow. The structural properties of the InAs NWs were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, we characterize atomic distribution of InAs NWs using energy-dispersive X-ray spectroscopy (EDX) analysis.