• 한국전기화학회:학술대회논문집
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• 2002.07a
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• pp.203-206
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• 2002

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.185-190
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• 2004

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.585-590
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• 2003

Cobalt oxygen carrier complex N,N'-ethylenebis(3-methoxysalycylideneiminato)cobalt(II), Co(3MeOsalen) was prepared at $25{\circ}C$. UV and visible absorption spectra of the complex and hydrazobenzene were studied in non-aqueous solvent methanol in the range of wavelength 200-600 nm. The oxidation of hydrazobenzene by oxygen in non-aqueous solvent is catalysed by Co(3MeOsalen). In the presence of triphenylphosphine($PPh_3$), the rate decreases in methanol. This is presumably attributable to the coordination of $PPh_3$ to the Co(3MeOsalen), resulting in the catallytically inactive compound. The initial rates of the oxidation of hydrazobenzene with the ligand triphenylphosphine were measured by the theoretical values of the rates, Rate=$k_1+k_2K_1[P]/1+K_1[P]+K_1K_2[P]^2$. This fact would be a poorer σ-donor ligand than methanol.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.28-33
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• 2009

Carbon nanotube supported molybdenum carbide catalysts were prepared as a function of various preparation conditions and characterized, and their catalytic activities were compared through electrochemical oxidation of methanol. To overcome the low activity of a transition metal catalyst, carbon nanotube was used as a support, and the amount and the kind of precursors, acid treatment method, and carburization temperature were varied for the catalyst preparation. ICP-AES, XRD and TEM were used for the catalyst characterization. Based on the various preparation methods of carbon nanotube supported molybdenum carbide catalysts ($Mo_2C/CNT$), the size and the amount of supported catalysts could be controlled, and their effects on the electrochemical oxidation could be explained.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.119-124
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• 2018

The production of methyl N-phenyl carbamate by an oxidative carbonylation method of aniline and methanol is of great interest as an environmentally friendly process that can replace the monomer production process of a polymer produce using conventional phosgene. In this study, heterogeneous catalysts were prepared by using Y-zeolite, $SiO_2$, $Al_2O_3$ as support, and oxidative carbonylation continuous operation from aniline and methanol was attempted using the prepared heterogeneous catalyst. Batch reactor was used to determine the support, and various reaction conditions such as reaction temperature, reaction pressure, and effect of promoter were established using palladium catalyst. A reaction kinetics study was conducted under optimum reaction conditions. The basic data for carbamate process development were obtained by performing continuous operation for a long time under established reaction condition.

• Journal of Life Science
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• v.14 no.2
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• pp.269-274
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• 2004

Using heterogeneous catalyst, esterification reaction of soybean oil (SBO) with methanol was investigated. Distributions of components in mixtures of soybean oil and methanol were measured at temperatures ranging from 40 to $65^{\circ}C$. Glycerine contents of reaction mixtures were measured for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)$_2$, MgO, Mg(OH)$_2$, and Ba(OH)$_2$. Based on the measured glycerine concentrations, conversions of the reaction mixtures were calculated. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by heterogeneous catalyst, final conversion was strongly dependent on the alkalinity of the heterogeneous catalyst, and increased with the alkalinity of the catalyst material. Hydroxides from the alkali metals were more effective than oxides, which actually had no catalytic effects. When Ca(OH)$_2$ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4%. The final conversion and reaction rate increased with reaction temperature, and showed substantial increment at reaction temperature of 5$0^{\circ}C$. When cosolvent, CHCl$_3$, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)$_2$, maximum value of final conversion was appeared at dose of 3%.

• Journal of the Korean Chemical Society
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• v.38 no.4
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• pp.302-308
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• 1994

Homogeneous catalytic oxidation of hydrazobenzene was investigated by employing pentadentate Schiff base complexes such as [Co(II)(Sal-DPT)(H$_2$O)] and [Co(II)(Sal-DET)(H$_2$O)] in oxygen-saturated methanol solvent. The oxidation product of hydrazobenzene(H$_2$AB) was trans-azobenzene(trans-AB). The rate constants of oxidation reaction measured by UV-visible spectrophotometry were observed as $6.06{\times}10^{-3}sec^{-1}$ for [Co(II)(Sal-DPT)(H$_2$O)] and $2.50{\times}10^{-3}sec^{-1}$ for [Co(II)(Sal-DET)(H$_2$O)]. The mechanism of oxidation reaction for H$_2$AB by homogeneous activated catalysts has been proposed as following. H$_2$AB + Co(II)(L)(H$_2$O) + O$_2$ $\rightleftharpoons^K_{MeOH}Co(III)(L)O_2{\cdot}H_2AB + H_2O\longrightarrow^{k}Co(II)(L) + trans-AB + H_2O_2$ (L: Sal-DPT and Sal-DET)

• Composites Research
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• v.34 no.5
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• pp.277-282
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• 2021

Graphene oxide can be reduced to graphene under supercritical fluid condition even without using a specific reducing agent or applying a high thermal process. In this study, a process for converting graphene oxide into graphene was studied under supercritical fluid conditions in methanol and ethanol solvents. When the structure of asprepared graphene was analyzed by using FE-SEM and XRD, the reduction of graphene oxide in supercritical fluid condition was more affected by the change of solvent than other variables such as concentration of graphene oxide and reaction time. The use of ethanol showed better results for the reduction than the use of methanol. The graphene prepared in this study was mixed with epoxy resin up to 20 wt.% to make composites, and the thermal conductivity of the composites were analyzed. Thermal conductivity of the composite increased proportionally with graphene loadings. The graphene prepared in supercritical ethanol condition was more effective on the thermal conductivity of the composite.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.515-519
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• 2014

The fuel properties of biodiesel produced by changing the mixing ratio of methanol and ethanol in trans-esterification of soybean oil and lard were evaluated in this paper. The solubility of oil and fat in ethanol was higher than that in methanol. Also the more homogeneous biodiesel was produced as increasing the mole ratio of ethanol. The conversion characteristics of lard was the best at the mixing mole ratio of methanol and ethanol was 6 : 6 at the reaction temperature of $60^{\circ}C$. On the other hands, the best biodiesel conversion characteristics for soybean oil was obtained at the mixing mole ratio of 3 : 3. The kinematic viscosities of soybean oil and lard based biodiesel were 4.17~4.35 cSt and 4.69~4.93 cSt, respectively. The oxidation stability and higher heating value increased with increasing the mole ratio of ethanol. The oxidation stability satisfied the criteria of biodiesel quality of 6 hours. And finally, the higher heating value was approximately 40 MJ/kg.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.956-960
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• 1998

Cu-Zn and Cu-Zn-Ti catalysts for the steam reforming of methanol were prepared. This reaction was carried out at atmospheric pressure, $250^{\circ}C$, steam/methanol molar ratio 1.5, and contact time 0.1 g-cat.hr/mL-feed. In case of the catalyst with 3 mol% of $TiO_2$, the activity was superior to that of catalysts without $TiO_2$. The reaction products were mainly hydrogen and carbon dioxide. It was found that catalytic activity was not related to specific surface area but affected by metallic copper area which was measured by $N_2O$ decomposition and increased with the addition of $TiO_2$ content. XPS and XRD showed that the oxidation state of zinc was not changed during reaction, but oxidation states of copper existed in Cu(0) or Cu(I).