• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.227-238
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• 2016

This review article highlights different types of nano-sized catalysts for the selective alcohol oxidation to form aldehydes (or ketones) with supported or immobilized metal nanoparticles. Metal nanoparticle catalysts are obtained through dispersing metal nanoparticles over a solid support with a large surface area. The nanocatalysts have wide technological applications to industrial and academic fields such as organic synthesis, fuel cells, biodiesel production, oil cracking, energy conversion and storage, medicine, water treatment, solid rocket propellants, chemicals and dyes. One of main reactions for the nanocatalyst is an aerobic oxidation of alcohols to produce important intermediates for various applications. The oxidation of alcohols by supported nanocatalysts including gold, palladium, ruthenium, and vanadium is very economical, green and environmentally benign reaction leading to decrease byproducts and reduce the cost of reagents as opposed to stoichiometric reactions. In addition, the room temperature alcohol oxidation using nanocatalysts is introduced.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.194-199
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• 2008

In this study, the effective method to esterify the free fatty acids in jatropha oil was examined. Compared to other plant oils, the acid value of jatropha oil was remarkably high, 11.5 mgKOH/g. So direct transesterification by a base catalyst was not suitable for the oil. After the free fatty acids were esterified with methanol, jatropha oil was transesterified. The activities of four solid acid catalysts were tested and Amberlyst-15 showed the best activity for the esterification. After constructing the experiment matrix based on RSM and analyzing the statistical data, the optimal esterification conditions were determined to be 6.79% of methanol and 17.14% of Amberlyst-15. After the pretreatment, jatropha biodiesel was produced by the transesterification using KOH in a pressurized batch reactor. Jatropha biodiesel produced could meet the major specifications of Korean biodiesel standards; 97.35% of FAME, 8.17 h of oxidation stability, 0.125% of total glycerol and $0^{\circ}C$ of CFPP.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.237-240
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• 2000

본 연구에서는 비스페놀 A, 에피크로로히트린을 반응시킨 에폭시 기본주제를 중심으로 경화제, 희석제, 충진제, 촉매 등을 배합하여 토목, 건축용 반고체형 에폭시 접착제를 개발하였다. 여기서 특히 에폭시 주제와 희석제의 종류 및 배합비율에 따른 기본 물성, 접착성능 등을 측정하였다. 상온 경화 특성을 측정하기 위하여 경화시 간을 측정한 결과 희석제의 종류와 관계없이 희석제의 양이 증가할수록 경화시간이 증가하고 경화온도도 증가하는 경향을 알 수 있었으며 촉매의 양이 적을 경우가 경화시간이 빠른 것을 알 수 있었다. 또한 경화 시간은 30분 내지 40분 정도로 상온에서 사용할 수 있을 것으로 기대한다. 접착력 시험 결과는 촉매의 양이 적당한 때 가장 좋은 접착력을 나타내고 희석제 중에서 HDGE의 경우가 가장 좋은 접착력을 나타내었고 희식제의 양이 증가할수록 접착력은 증가하였다. 실리카와 철분을 섞어 반고체형 에폭시 접착제를 제조한 경우 기존의 제품보다 우수한 접착력을 나타내었다. 따라서 본 연구에서 개발한 반고체형 접착제는 제조공정 코스트 등에 대한 검토와 함께 제품화하여 토목, 건축 분야의 콘크리트 균열 접착, 볼트와 콘크리트의 접합, 목재의 접합 등에 간편하게 사용될 수 있으며, 배합물질과 비율에 따라 전기전자. 토목건축, 자동차산업 등의 산업용 접착제로서 응용될 수 있을 것으로 기대된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.7
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• pp.558-565
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• 2008

Solid oxide fuel cell(SOFC) has a higher fuel flexibility than low temperature fuel cells, such as polymer electrolyte fuel cell(PEMFC) and phosphoric acid fuel cell(PAFC). SOFCs also use CO and $CH_4$ as a fuel, because SOFCs are hot enough to allow the CH4 steam reformation(SR) reaction and water-gas shift(WGS) reaction occur within the SOFC stack itself. Diesel is a good candidate for SOFC system fuel because diesel reformate gas include a higher degree of CO and $CH_4$ concentration than other hydrocarbon(methane, butane, etc.) reformate gas. Selection of catalyst for autothermalr reforming of diesel was performed in this paper, and characteristics of reforming performance between packed-bed and microchannel catalyst are compared for SOFC system. The mesh-typed microchannel catalyst also investigated for diesel ATR operation for 1kW-class SOFC system. 1kW-class diesel microchannel ATR was continuously operated about 30 hours and its reforming efficiency was achieved nearly 55%.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.61-66
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• 2022

This study is to increase the surface area and maximize the effect of the catalyst by coating a nanometersized metal catalyst material on the anode layer using atomic layer deposition (ALD) technology. ALD process is known to produce uniform films with well-controlled thickness at the atomic level on substrates. We measured the performance by coating metals (Ni) on Ni/YSZ, which is the most widely known anode material for solid oxide fuel cells. ALD coatings began to show a decrease in cell performance over 3 nm coatings.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.64-69
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• 2016

The applications of heterogeneous catalyst have been relatively active area of research in the biodiesel process. These catalysts have the benefit of easy recovery and reusability of the catalyst. The objective of this study is to find out significant effect of calcination temperature on $K_2CO_3/{\gamma}-Al_2O_3$ catalytic activity in the biodiesel formation reaction. As a results, the temperature at which a catalyst was calcined had very important influence on the catalytic activity. The catalytic activity increased up to $600^{\circ}C$, but it severely decreased above the temperature. The reduction of catalyst activity at high temperature would be due to the deduction of the active sites of Al-O-K and $Al-O_2-K$.

• Journal of the Korean Ceramic Society
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• v.39 no.10
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• pp.988-993
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• 2002

Electrochemical cells for decomposing $NO_x$ were fabricated using a hydrothermally synthesized lanthanum stannate pyrochlore catalyst. Thick film of the catalyst on the YSZ electrolyte disk was produced by screen-printing a paste consisted of $La_2Sn_2O_7$ and YSZ powders. Direct current was applied to the electrochemical cell to promote an electrochemical catalytic decomposition of $NO_x$. $NO_x$ decomposition behavior of the rectant gas mixture ($NO_x$ 0.1%, $O_2$ 2%) was investigated at 700${\circ}C$ under atmosphere pressure using on-line gas chromatography and $NO_x$ analyzer. It was observed that microstructure of the catalyst layer significantly influences the electrocatalystic decomposition of $NO_x$.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.511-515
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• 2007

The yield of oil was rapidly increased at $440^{\circ}C$ compared to $400^{\circ}C$ and $420^{\circ}C$ when the isothermal pyrolysis of waste ship lubricating oil was carried out in tubular type reactor, and pyrolysis was almost finished within 30 min. The yield of gas was decreased depending on the reaction temperature in which that of solid was not much changed. Pyrolysis experiments of waste ship lubricating oil were carried out with used ZSM-5 produced from a petrochemical process. The yield of gas was highly increased in the case of used ZSM-5 and fresh ZSM-5 compared to the case without catalyst. The produced oil and gas were almost constant for fresh ZSM-5 and used ZSM-5 at the same reaction temperature. In the reaction temperature $400{\sim}440^{\circ}C$, the selectivity of $C_5-C_{11}$ was two times higher with fresh ZSM-5 and used ZSM-5 than the case without catalyst.

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.185-190
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• 2005

Solid phase synthesis of 16, which is a derivative of the first systemic fungicide, carboxin 1 was described. Reaction of 1,3-oxathiolane derivative with solid resin of 4-hydroxy-3-nitrobenzophenone 6 gave 9 in 82% yield. Oxidation of sulfur in the solid 1,3-oxathiolane 9 by MCPBA followed by a ring expansion reaction under the acid catalyst afforded the corresponding dihydro-1,4-oxathiin derivative 12. Treatment of the solid 1,3-oxathiolane 9 with p-methoxyaniline resulted in 1,3-oxathiolane 14, 1,3-oxathiolane sulfoxide 15, dihydro-1,4-oxathiin 16, and acetoacetanilide derivative 17 in 41%, 35%, 14%, 10% yields, respectively.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.372-376
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• 1998

Supported Pd($Pd/AlF_3$, $Pd/{\gamma}-Al_2O_3$) catalysts and solid-acid catalysts(${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$, $AlF_3$) were used to perform dechlorination of HCFC-142b(1-chloro-1,1-difluoroethane) in the presence of excess hydrogen. In the reactions the effects of reaction temperature, the mole ratio(r) of $H_2$ to HCFC-142b and the amount of supported Pd on dechlorination of HCFC-142b into HFC-143a(1,1,1-trifluoroethane) or HFC-152a(1,1-difluoroethane) were investigated. The experimental results showed that the conversion of HCFC-142b to product gases were 60% and 92%, respectively, and the selectivity to HFC-143a in the product gases were 58% and 64% for $Pd/AlF_3$ and $Pd/{\gamma}-Al_2O_3$ catalysts, respectively. On these catalysts an optimum reaction condition was found at $200^{\circ}C$ with the space time of reactant gases as 1.05 second and the mole ratio of $H_2$ to HCFC-142b as 3. Solid-acid catalysts were also tested at the same reaction condition. The results showed that the conversions of HCFC-142b to product gases were 12%, 8% and 7%, and the selectivities to HFC-152a were 94%, 92% and 90% for ${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$ and $AlF_3$ catalysts, respectively.