• 한국분말재료학회지
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• 제25권3호
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• pp.203-207
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• 2018

Plastic pollution is threatening human health and ecosystems, resulting in one of the biggest challenges that humanity has ever faced. Therefore, this study focuses on the preparation of macroporous carbon from biowaste (MC)-supported manganese oxide ($MnO_2$) as an efficient, reusable, and robust catalyst for the recycling of poly(ethylene terephthalate) (PET) waste. As-prepared $MnO_2/MC$ composites have a hierarchical pore network and a large surface area ($376.16m^2/g$) with a narrow size distribution. $MnO_2/MC$ shows a maximum yield (98%) of bis(2-hydroxyethyl)terephthalate (BHET) after glycolysis reaction for 120 min. Furthermore, $MnO_2/MC$ can be reused at least nine times with a negligible decrease in BHET yield. Based on this remarkable catalytic performance, we expect that $MnO_2$-based heterogeneous catalysts have the potential to be introduced into the PET recycling industry.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.415-417
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• 2009

A low temperature decal (LTD) transfer method is tried to fabricated hydrocarbon (HC) membrane based MEA. Sandwiched structures of outer ionomer/catalyst/carbon coating/substrate, which had been developed for Nafion membrane, are used for transfer of catalyst to the HC membrane. Performances of the HC MEA before and after 500hr continuous operation are compared and it is found that a severe delamination occurs at the interface between the HC membrane and the catalyst layer, which is the main reason of the low performance and its degradation. The delamination is due probably to the different nature of HC membrane to the Nafion ionomer. A substitutional method, therefore, is suggested to overcome this. In such a way, the outer ionomer process is removed and the low transfer rate of catalyst by skipping the ionomer process is compensated with optimization of other process variables such as transfer time or temperature. The resulting performance is superior to the original LTD method, which can be explained in terms of low resistive components both in ohmic and kinetic.

• 전기화학회지
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• 제26권4호
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• pp.64-70
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• 2023

급격한 온실가스 배출량 증가로 인해 지구 온난화가 심화되고 있다. 이로 인해 탄소중립의 필요성과 이행이 더욱 절실해졌다. 이를 위해 여러 가지 신재생에너지 중 수소에 대한 관심이 부각되고 있다. 수소는 지구 상에 풍부한 자원이며 무탄소 전원으로 친환경적이다. 궁극적으로 물의 전기분해에 의해 친환경 수소를 얻을 수 있다. 하지만 산소 발생 반응에 사용되는 촉매는 고가이며 희귀하고 촉매의 내구성에 문제가 있어 어려움을 겪고 있기 때문에 비귀금속 촉매의 개발이 필요하다. 본 총설에서는 최근 발표된 산소 발생 촉매 중 비귀금속 촉매인 Co와 Mo 기반의 촉매를 정리, 요약하여 소개하고 있다. 이를 통해 비귀금속 촉매의 활성과 내구성을 증가시키기 위한 촉매의 특성 설계를 이해하는 데 도움이 될 것이다.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2003년도 연료전지심포지움 2003논문집
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• pp.183-187
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• 2003

Carbon nanotubes, prepared by the catalytic decomposition of acetylene at $700^{\circ}C$ over a Mm based $AB_5$ hydrogen storage alloy hydride catalysts, have been used as a support for platinum electrocatalysts. The performance of this electrocatalyst In proton exchange membrane fuel cells has been studied and discussed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.37-40
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• 2007

Diesel autothermal reforming(ATR) is an effective method for hydrogen production. But, diesel ATR has several problems such as the sulfur poisoning of catalyst and carbon deposition during reforming reactor. Especially, carbon deposition is a severe problem, which causes rapid performance degradation, in the reforming reaction. Ethylene among the reformate gas is a carbon precursor. Effective decomposition of ethylene is an important issue. In this paper, we investigated the carbon deposition from ethylene in the reforming reaction for proper reaction condition of diesel ATR. We achieved relatively high performance of diesel ATR under $H_{2}O/C=0.8$, $O_{2}/C=3$ condition that was based on the experiment of ethylene reforming reaction.

• 공업화학
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• 제22권3호
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• pp.243-248
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• 2011

상온에서 작동하는 고감도 수소 가스센서를 제조하기 위하여 Pt 촉매가 증착된 다공성 탄소나노섬유를 제조하였다. 나노섬유는 polyacrylonitrile을 탄소전구체로 하여 전기방사법을 이용하여 제조되었고, 탄소나노섬유의 제조를 위하여 열처리 공정을 거쳤다. 다음으로, 탄소나노섬유에 화학적 활성화 공정을 통하여 가스 흡착을 위한 높은 비표면적과 기공구조를 부여하였다. Pt는 수소가스에 대한 촉매효과를 위하여 스퍼터링법을 통해 다공성 탄소나노섬유에 증착되었다. 탄소나노섬유는 화학적 활성화 공정을 통해 비표면적이 $2093m^2/g$으로 100배 이상 증가하였고, 약 60 vol%의 미세기공이 부여되었다. Pt는 다공성 탄소나노섬유의 형태를 그대로 유지하면서 얇고 고르게 증착되었다. 제조된 가스센서의 반응속도와 민감도는 비표면적, 미세기공율의 증가와 Pt 증착에 의하여 증가하였다. 결과적으로 수소가스에 대한 탄소나노섬유 상온에서 감응특성은 화학적 활성화와 Pt의 촉매효과에 의하여 향상됨을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.635-638
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• 2011

A simple and efficient method for the synthesis of $\beta$-amino carbonyl compounds by one-pot three-component Mannich reaction of acetophenone, aromatic aldehydes and aromatic amines using a carbon-based solid acid (CBSA), as an effective and reusable catalyst, is described. The present methodology offers several advantages such as simple procedure with an easy work-up, shorter reaction times, and high yields.

• 한국수소및신에너지학회논문집
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• 제32권3호
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• pp.149-155
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• 2021

Most of the reformer experiments have been conducted only in high-temperature operation conditions above 700℃. However, to design high efficiency solid oxide fuel cell, it is necessary to test actual reaction performance in mid-temperature (550℃) operation areas. In order to study the operation characteristics and performance of commercial reforming catalysts, a reforming performance experiment was conducted on mid-temperature. The catalysts used in this study are Ni-based FCR-4 and Ru-based RuA, RuAL. Experiments were conducted with a Steam-to-carbon ratio of 2.0 to 3.0 under gas hourly space velocity (GHSV) 2,000 to 5,000 hr-1. As a result, RuA and RuAL catalysts showed similar gas composition to the equilibrium regardless of the reforming temperature. However, the FCR-4 catalyst showed a lower hydrogen yield compared to the equilibrium under high GHSV conditions.

• 한국재료학회지
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• 제15권4호
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• pp.246-251
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• 2005

Plasma enhanced chemical vapor deposition(PE-CVD) method has an advantage in synthesizing carbon nanotubes(CNTs) at lower temperature compared with thermal enhanced chemical vapor deposition(TE-CVD) method. In this study, CNTs was prepared by using PE-CVD method. The growth rate of CNT was faster more than 100 times on using Invar alloy than iron as catalyst. It was found that chrome silicide was formed at the interface between chrome layer and silicon substrate which should be considered in designing process. Nanoparticles of Invar catalyst were found oxidized on their surfaces with a depth of 10 m. Microstructure was analyzed by scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, and energy dispersive x-ray spectrometry. Based on the result of analysis, growth mechanism at an initial stage was suggested.

• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.549-555
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• 2019

Electrocatalysis of oxygen reduction reaction (ORR) using Pt nanoparticles or bimetal on carabon was studied. Currently, the best catalyst is platinum, which is a limited resource and expensive to commercialize. In this paper, we investigated the cheaper and more active electrocatalysts by making Pt nanoparticles and adding 3D transition metal such as copper. Electrocatalysts were obtained by chemical reduction based on ethylene glycol solutions. Elemental analysis and particle size were confirmed by XRD and TEM. The electrochemical surface area (ECSA) and activity of the catalyst were determined by electrochemical techniques such as cyclic voltammetry and linear sweep voltammetry method. The commercialized Pt support on carbon (Pt/C, JM), synthesis Pt/C and synthesis Pt3Cu1 alloy nanoparticles supported on carbon were compared. We confirmed that the synthesized Pt3-Cu1/C has high electrochemical performance than commercial Pt/C. It is expected to develop an electrocatalyst with high activity at low price by increasing the oxygen reduction reaction rate of the fuel cell.