• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.386-388
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• 2009

차세대 에너지로 연료전지가 각광을 받고 있는 현재, 세계 각국에서는 연료전지의 상용화를 위해 노력하고 있다. 그러나 촉매분야에서 백금계 촉매의 사용량의 문제에 따른 매장량 한계점과 귀금속이라는 문제점이 존재하기 때문에 이에 대하여 대책강구가 필요한 시점이다. 이에 백금 촉매의 활성을 증대하고자 나노 크기의 제어 연구가 진행되고 있다. 또한, 촉매의 구조적인 면에 따라 촉매의 활성이 달라지는 점을 착안하여 백금계의 나노 형상 조절 연구와 백금계 촉매를 대체할 비백금계의 촉매 개발 연구가 활발히 진행되어지고 있다. 이에 본 연구는 백금계 촉매 중 Pd을 polyol process에 의한 나노 형상 조절을 통하여 단위 질량당(or 단위 부피당) 촉매의 활성을 높이고자 하였다. Polyol process에서는 환원제, 계면활성제, 온도, 시간, 기타 첨가제에 따라 나노 형상이 다르게 조절되는데, 이에 계면활성제로 PVP를 사용하고, 반응속도 및 형상조절을 위해 다양한 첨가제를 이용하여 polygonal Pd NPs을 형성하였다. 본 나노 형상 조절에서는 첨가제와 온도가 가장 큰 영향을 미치는 요인으로 착안하여 그에 따른 polygoanl Pd NPs의 사이즈 조절을 통해 전기화학 특성이 차이의 연구에 중점을 두었다. 이에 따라 나노 형상 조절이 된 Pd촉매를 이용하여 상용화된 촉매(Pd/C(XC-72R))에 비하여 전기화학적인 특성의 차이와 Pd 촉매의 촉매적 특성의 효과를 보고자 한다.

• The Science & Technology
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• v.30 no.3 s.334
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• pp.86-87
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• 1997

95년 5월 서울대 내에 설립된 분자촉매연구센터는 인체 내에서 가공할만한 힘을 발휘하는 촉매제인 "효소"와 가장 흡사한 생체와 생체모방촉매 개발을 중점과제로 삼고 있다. 3백여명의 연구진이 포진한 이 연구소는 피혁회사에서 사용되는 모피를 부드럽게 하는 인공촉매제 개발에도 성공한 바 있다.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.49-56
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• 2005

Hot firing performance test of hydrazine decomposition catalyst used for monopropellant thruster of the satellite and the launch vehicle was performed. Test equipment for catalyst test was developed in collaboration with Hanwha Corp., reaction delay time, catalyst activity and granule stability of the catalyst firing performance were measured and analyzed with the equipment. In addition, the current development of prototype catalyst is introduced.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.84-90
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• 2020

The adhesion strength of two konds of solid propellants(primary propellant/secondary propellant) was studied by coating agent of adhesion composition composed of organic solvent, curing agent, and cure catalyst. The coating agent using FeAA, cure catalyst, resulted propellant breaking at more 0.14 wt% and interface breaking at less 0.10 wt%. The TPB cure catalyst of confirmed the result of the interface breaking immediately after curing of the secondary propellant. In addition, the coating agent using TPB was found to increase the adhesion strength between the primary propellant and the secondary propellant over time.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.12-23
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• 1984

This study was carried out to investigate on the catalytic pyrolysis products of hardwood (Alnus hirsuta (Spach) Rupr. Quercus acutissima Carruters, Robinia pseudoacacia L., and Populus tomentaglandulosa T. Lee) and comparing the rate of catalytic pyrolysis from untreated wood (ordinary wood) with that of treated wood with catalizer (Ammonium phosphate, Ammonium sulfate, Ammonium chloride and Urea). The results were summerized as follows; 1) It is the Populus tomentiglandulosa T. Lee that the species has the most content of holocellulose and pentosan. And Populus tomentiglandulosa exhibited high yield of the distillate in pyrolysis products by Ammonium phosphate with catalizer. 2) The distillate of pyrolysis products is decreased in accordance with increasing catalytic concentration. And untreated wood (ordinary wood) with catalizer has the most distillate of pyrolysis products. 3) The yield of charcoal in pyrolysis products is increased in accordance with increasing catalytic concentration and lignin content of species. 4) The caloric values of charcoal in pyrolysis products is decreased with increasing catalytic concentration. And untreated wood (ordinary wood) with catalizer had the most caloric values, but the caloric values of charcoal did not show statistically significent difference at 5% levels in catalizer.

• Composites Research
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• v.28 no.6
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• pp.395-401
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• 2015

This study investigated the thermal stability of Grubbs' catalyst and its reactivity with self-healing agents for self-healing damage repair. Four types of Grubbs' catalyst supplied by manufacturers were considered and each catalyst was tested in as-received and grinded conditions. Four types of self-healing agents were prepared by varying the mixing ratio of dicyclopentadiene (DCPD) and 5-ethylidene-2-norbonene (ENB). Heat flows as a function of temperature were measured through a differential scanning calorimetry (DSC) to determine the thermal stability of catalysts. Reaction heats of self-healing agents with the catalyst were measured to evaluate the reactivity of the catalyst. For this evaluation, Fluka Chemika Grubbs' catalyst was used based on the maximum temperature and the time to reach the maximum temperature. According to the results, catalysts had different shapes depending on the manufacturer and the results showed that the smaller the size of the catalyst the higher the reactivity with self-healing agents. As the ENB ratio in self-healing agents increased, the maximum temperature increased, and the time to reach the maximum temperature decreased. As the amount of the catalyst increased, the maximum temperature increased, and the time to reach the maximum temperature decreased. Considering the thermal stability of the catalyst and its reactivity with the self-healing agent, combination of 0.5 wt% catalyst and the D3E1 self-healing agent was optimal for self-healing damage repair. Finally, as the thermal decomposition may occur depending on the environmental temperature, the catalyst must not be exposed to temperature higher than that is necessary to maintain the thermal stability of the catalyst.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.627-635
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• 2019

Cement-asbestos slate is the main asbestos containing material. It is a product made by combining 10~20% of asbestos and cement components. Man- and weathering-induced degradation of the cement-asbestos slates makes them a source of dispersion of asbestos fibres and represents a priority cause of concern. When the asbestos enters the human body, it causes cellular damage or deformation, and is not discharged well in vitro, and has been proven to cause diseases such as lung cancer, asbestos, malignant mesothelioma and pleural thickening. The International Agency for Research on Cancer (IARC) has designated asbestos as a group 1 carcinogen. Currently, most of these slats are disposed in a designated landfill, but the landfill capacity is approaching its limit, and there is a potential risk of exposure to the external environment even if it is land-filled. Therefore, this study aimed to exam the possibility of detoxification of asbestos-containing slate by using exothermic reaction and heat treatment. Cement-asbestos slate from the asbestos removal site was used for this experiment. Exothermic catalysts such as calcium chloride(CaCl₂), magnesium chloride(MgCl₂), sodium hydroxide(NaOH), sodium silicate(Na₂SiO₃), kaolin[Al₂Si₂O₅(OH)₄)], and talc[Mg₃Si₄O₁₀(OH)₂] were used. Six catalysts were applied to the cement-asbestos slate, respectively and then analyzed using TG-DTA. Based on the TG-DTA results, the heat treatment temperature for cement-asbestos slate transformation was determined at 750℃. XRD, SEM-EDS and TEM-EDS analyses were performed on the samples after the six catalysts applied to the slate and heat-treated at 750℃ for 2 hours. It was confirmed that chrysotile[Mg₃Si₂O₅(OH₅)] in the cement-asbestos slate was transformed into forsterite (Mg₂SiO₄) by catalysts and heat treatment. In addition, the change in the shape of minerals was observed by applying a physical force to the slate and the heat treated slate after coating catalysts. As a result, the chrysotile in the cement-asbestos slate maintained fibrous form, but the cement-asbestos slate after heat treatment of applying catalyst was broken into non-fibrous form. Therefore, this study shows the possibility to safely verify the complete transformation of asbestos minerals in this catalyst- and temperature-induced process.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.739-745
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• 2017

Research of ADN-based monopropellant thruster is progressed by developed countries in Europe to replace toxic hydrazine, and ADN-based monopropellant thruster system is the only system that was proved in space environment. In this research, ADN-based propellant and catalyst was fabricated to develop ADN-based monopropellant thruster, and catalytic combustion performance with fabricated propellant and catalyst were evaluated with DSC-TG analysis. Catalytic combustion of propellant and catalyst was determined with firing test using 5 N scale liquid monopropellant thruster.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6575-6580
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• 2013

Various modified SCR catalysts were prepared and tested to improve the strength of catalysts for use under severe conditions. The SCR catalysts were modified with a binder and dispersion agent, and tested at the fixed bed reactor. FT-IR and $H_2$-TPR were used to analyze the degree of hydrogen use and ammonia adsorption by the modified catalysts. In the case of the SCR catalysts coated with 2.3g of the binder, 4.7g of ethanol, and 0.1g of dispersion agent, the strength of catalyst was increased by approximately 12%. On the other hand, despite the enhancement of strength, the activities of the SCR catalysts were decreased by 2-10%. When the mixed solution composed of binder, dispersion agent and $SiO_2$ solution was precipitated on the catalyst, the $NO_x$ conversion of the catalyst was decreased slightly. The Bronsted acid site and Lewis acid site worked as the activators for the SCR reaction, and were decreased by $SiO_2$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.292-295
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• 2004

Firing performance test of hydrazine decomposition catalyst which is used in mono-propellant thruster of satellite and launcher was peformed. Equipment for catalyst test was developed and with this equipment reaction delay time, catalyst activity, granule stability of the catalyst firing performance was measured and analyzed.