• 한국수소및신에너지학회논문집
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• 제26권6호
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• pp.524-531
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• 2015

To improve the electrochemical and mechanical characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The SPEEK organic-inorganic blended composite membranes were prepared by sol-gel casting method. It was loaded with the highly dispersed ceria and cesium-substituted molybdosilicic acid (Cs-MoSiA) and 1,4-diiodobutane which was cross-linking agent contents of $10{\mu}L$. Cs-MoSiA was added to increase proton conductivity. Ceria ($CeO_2$) was used as a free radical scavenger which degrade the membrane in polymer electrolyte membrane water elctrolysis (PEMWE). In conclusion, CL-SPEEK/Cs-MoSiA/Ceria 1% composite membrane showed high proton conductivity 0.2104 S/cm at $25^{\circ}C$ which was better than Nafion 117 membrane.

• 센서학회지
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• 제4권4호
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• pp.23-28
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• 1995

백금작업전극과 광가교화된 효소고정화막을 가진 ISFET 포도당 및 자당센서가 제조되었다. 효소반응의 부산물인 과산화수소수($H_{2}O_{2}$)는 백금전극표면에서 분해되어 센서의 감지특성을 개선시키고, 광가교화 고분자(PVA-SbQ)가 효소고정화막으로 이용되어 센서의 응답시간을 단축하였다. 그리고 백금전극의 면적변화에 따라 센서의 응답크기는 증가하였다. 센서의 응답시간은 $3{\sim}5$분이었으며, $30{\sim}300mg/dl$의 포도당 및 자당농도에서 센서의 선형적인 응답을 보였다.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.212-220
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• 2015

The engineering plastic of sulfonated polyether ether ketone (SPEEK) as a polymer matrix has been developed in this lab to replace Nafion, solid polymer electrolytes of perfluorosulfonic acid membrane which has several flaws such as high cost, and limited operational temperature above $80^{\circ}C$. The SPEEK was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstosilicic acid (Cs-TSiA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TSiA/ceria 1% membrane showed the optimum results such as 0.1882 S/cm of proton conductivity at $80^{\circ}C$, and 99.61 MPa of tensile strength which were better than Nafion 117 membrane.

• Journal of Electrochemical Science and Technology
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• 제11권3호
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• pp.273-281
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• 2020

Constructing and making highly active and stable nanostructured Pt-based catalysts with ultralow Pt loading are still electrifying for electrochemical applications such as water electrolysis and fuel cells. In this study, MoO₃ ribbons (RBs) of few micrometer in length is successfully synthesized via hydrothermal synthesis. Subsequently, 3-dimentional (3D)-silicate layer for about 10 to 15 nm is introduced via chemical deposition onto the pre-formed MoO₃ RBs; to setup the platform for Pt metaldots (MDs) deposition. In comparison with the bare MoO₃ RBs, the MoO₃-Si has served as a efficient solid-support for stabilizing and accommodating the uniform deposition of sub-2 nm Pt MDs. Such a structural design would effectively assist in improving the electronic conductivity of a fabricated MoO₃-Si-Pt catalyst towards MOR; the interfaced, porous and 3D silicate layer has assisted in an efficient mass transport and quenching the poisonous CO_ads species leading to a significant electrocatalytic performance for MOR in alkaline medium. Uniformly decorated, sub-2 nm sized Pt MDs has synergistically oxidized the MeOH in association with the MoO₃-Si solid-support hence, synergistic catalytic activity has been achieved. Present facile approach can be extended for fabricating variety of highly efficient Metal Oxide-Metal Nanocomposite for energy harvesting applications.

• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.151-160
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• 2014

CL-SPEEK/Cs-TPA/$CeO_2$ composite membrane was prepared for polymer electrolyte membrane water electrolysis (PEMWE). In order to improve the electrochemical, mechanical, durabilities and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated and the organic-inorganic blend composite membranes was prepared by loading cesium-substituted tungstophosphoric acid (Cs-TPA) by titration method with cross-linking agent contents of 0.01mL. Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the PEMWE circumstance and to increase the duration of the membrane. CL-SPEEK/$Cs_{(1)}$-TPA/CeriaIn conclusion, 1% membrane showed the optimum results such as 0.119 S/cm at $80^{\circ}C$ of proton conductivity and 62MPa of tensile strength.

• Korean Chemical Engineering Research
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• 제55권4호
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• pp.478-482
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• 2017

고분자 전해질 연료전지의 구동과정 중 습도제어는 매우 중요한 제어 조건이다. 물 관리 측면에서는 저가습 조건이 유리하고, 배출수 활용 및 에너지 효율면에서는 고가습이 유리하다. 본 연구에서는 배출수 활용면에서 저가습과 고가습 구동 과정에서 배출수의 특성에 대해서 연구하였다. 배출수의 불순물은 막과 전극의 열화 과정에서 발생하는 것이므로 저가습과 고가습 조건에서 막전극합체(MEA)열화에 대해서도 연구하였다. 연료극 0% RH의 저가습 조건에서 라디칼 발생속도가 커 고분자 막 열화의 주요 원인임을 보였다. 양쪽 극 모두 고가습(RH 100%) 0.6 V에서 불소 이온 농도 약 20 ppb로 낮은 농도를 나타내서, 수전해 원료수로 사용하기에 충분하였다. 고가습 조건에서 배출한 응축수에서 0.2 ppb 이하의 매우 낮은 농도의 백금이 검출되었다.

• 공업화학
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• 제10권6호
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• pp.814-821
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• 1999

고비표면적의 활성탄소섬유(ACF: activated carbon fiber)를 분극성 전극으로 이용한 전기이중층 캐패시터(electric double layer capacitor)의 단위 cell test를 통하여, ACF의 비표면적, 세공의 크기 및 전기전도도가 캐패시터의 비축전용량에 커다란 영향을 미치고 있음을 확인할 수 있었고, 전해질은 $H^+$ 이온을 함유한 $H_2SO_4$이 가장 좋은 축전용량을 나타내었으나, 집전체 부식 등의 문제로 인하여, 실용화에 있어서는 우수한 충방전 거동을 나타낸 KOH계 전해질이 적당한 것으로 확인되었다. 분극성 전극으로 사용되는 ACF를 탄화 또는 후활성화 등이 후처리를 통하여 비축전용량을 급격히 증가시킬수 있었고, 3만회까지의 연속 충방전 실험에서 전기이중층 캐패시터는 2차전지에서는 찾아 볼 수 없는 매우 높은 충방전 효율과 긴 사용수명을 가지는 것을 확인할 수 있었다.

• 청정기술
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• 제18권2호
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• pp.183-190
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• 2012

PCB에칭에 의해 발생한 염화철 폐식각액 중 염화철을 산화시키고 구리를 석출시키는 전기화학적 재생공정은 환경오염을 줄이면서도 부산물을 얻어내어 경제성이 크다. 그러나, 염화철 폐식각액은 철과 구리, 두 가지 금속이 함께 함유되어 있기 때문에 전해조에서 일어나는 반응이 복잡하다. 본 연구에서는 회분식 공정을 통하여 전기화학적인 염화철 산화 및 구리 석출반응의 특성을 조사하고 관련된 공정변수들의 최적 조건을 도출해내었다. 염화철의 산화는 항상 원하는 수준으로 되었으며, 탄소 음전극을 사용한 반응에서 $350mA/cm^2$의 전류밀도와 12 g/L의 구리 농도 조건에서, $Fe^{2+}$이온의 비율이 높을수록 구리 석출 효율이 높았다. 또한, 도출해낸 최적 조건을 바탕으로 Bench 장치 연속운전을 통해서 scale-up 가능성을 확인하였다.

• 한국수소및신에너지학회논문집
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• 제17권2호
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• pp.149-157
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• 2006

Hydrogen as new energy sources is highly efficient and have very low environmental emissions. The proton exchange membrane fuel cell (PEMFC) is an emerging technology that can meet these demands. Therefore, the preparation of stable polymeric membranes with good proton conductivity and durability are very important for hydrogen production via water electrolysis with PEM at medium temperature above $80^{\circ}C$. Currently Nafion of Dupont and Aciflex of Asahi, etc., solid polymer electrolytes of perfluorosulfonic acid membrane, are the best performing commercially available polymer electrolytes. However, these membrane have several flaws including its high cost, and its limited operational temperature above $80^{\circ}C$. Because of this, significant research efforts have been devoted to the development of newer and cheaper membranes. In order to make up for the weak points and to improve the mechanical characteristics with cross -linking, acid-base complexes were prepared by the combination PSf-co-PPSS-$NH_2$ with PEEK-$SO_3H$. The results showed that the proton conductivity decreased in 17.6% and 40% but tensile strength increased in 78% and 98%, about $20.65\;{\times}\;10^6N/m^2$, in comparison with SBPSf/HPA and SPEEK/HPA complex membrane.

• 청정기술
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• 제28권2호
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• pp.182-192
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• 2022

This study provides an overview of the production costs of methane and hydrogen via water electrolysis-based hydrogen production followed by a methanation based methane production technology utilizing CO₂ from external sources. The study shows a comparative way for economic optimization of green methane generation using excess free electricity from renewable sources. The study initially developed the overall process on the Aspen Plus simulation tool. Aspen Plus estimated the capital expenditure for most of the equipment except for the methanation reactor and electrolyzer. The capital expenditure, the operating expenditure and the feed cost were used in a discounted cash flow based economic model for the methane production cost estimation. The study compared different reactor configurations as well. The same model was also used for a hydrogen production cost estimation. The optimized economic model estimated a methane production cost of $11.22/mcf when the plant is operating for 4000 hr/year and electricity is available for zero cost. Furthermore, a hydrogen production cost of $2.45/GJ was obtained. A sensitivity analysis was performed for the methane production cost as the electrolyzer cost varies across different electrolyzer types. A sensitivity study was also performed for the changing electricity cost, the number of operation hours per year and the plant capacity. The estimated levelized cost of methane (LCOM) in this study was less than or comparable with the existing studies available in the literature.