• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.440-447
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• 2006

Solid polymer electrolyte(SPE) membrane with electrodes embedded on both faces offer unique possibilities for the electrochemical cells like water electrolyzer with fuel cell. The Nafion 117 membrane was used as the SPE, and $Pt(NH_3)_4Cl_2$ and $NaBH_4$ as the electrocatalysts and reducing agent, respectively. The 'impregnation-reduction(I-R) method' has been investigated as a tool for the preparation of electrocatalysts for water electrolyzer by varying the concentration of reducing agent and reduction time at fixed concentration of platinum salt, 5 mmol/L. Pt-SPE electrocatalysts prepared by non-equilibrium I-R method showed the lowest cell voltage of 2.17 V at reduction time, 90 min and with concentration of reducing agent 0.8 mol/L and the cell voltage with those by equilibrium I-R method was 2.42 V at reduction time, 60 min and with concentration of reducing agent 0.8 mol/L. The cell voltage were obtained at a current density $1\;A/cm^2$ and $80^{\circ}C$. In water electrolysis, hydrogen production efficiency by Pt-SPE electrocatalyst is 68.2% in case of non-equilibrium I-R method and 61.2% at equilibrium I-R method.

• 한국표면공학회지
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• 제55권3호
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• pp.180-186
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• 2022

The production of hydrogen via water electrolysis (i.e., green hydrogen) using renewable energy is key to the development of a sustainable society. However, most current electrocatalysts are based on expensive precious metals and require the use of highly purified water in the electrolyte. We demonstrated the preparation of a non-precious metal catalyst based on CuCo₂O₄ (CCO) via simple electrodeposition. Further, an optimization process for electrodeposition potential, solution concentration and electrodeposition method was develop for a catalyst-substrate integrated electrode, which indicated the highly electrocatalytic performance of the material in electrochemical tests and when applied to an anion exchange membrane water electrolyzer.

• 한국환경과학회지
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• 제17권1호
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• pp.37-44
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• 2008

The electro-chemical decolorization of Rhodamine B (RhB) in water has been carried out by electro Fenton-like process. The effect of distance, material and shape of electrode, NaCl concentration, current, electric power, $H_2O_2$ and pH have been studied. The results obtained that decrease of RhB concentration of Fe(+)-Fe(-) electrode system was higher than that of other electrode system. The decrease of RhB concentration was not affected electrode distance and shape. Decolorization of electro Fenton-like reaction, which was added $H_2O_2$ onto the electrolysis using electrode was higher than electrolysis. Addition of NaCl decreased the electric consumption. The lower pH is, the faster initial reaction rate and reaction termination time observed.

• 환경위생공학
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• 제15권2호
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• pp.41-48
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• 2000

In this study, we have investigated the effect of the various operating conditions on the removal fluorine in the rinsed water for the semiconductor industry by using electrolysis process. The removal efficiency of fluorine was irrelevant to initial pH, and carbon anode was high-level treatment in the effect of various electrodes. Fluorine included in the wastewater is treated by the addition of a Ca(OH)2, removal efficiency of electrolysis was increased about 40%. Besides the removal efficiency of fluorine was increased as the current density was increased and this treatment system could reduce both the total sludge and running costs. The feasibility of the electrochemical treatment to the fluorine containing wastewater was verified from this study.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.99-108
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• 2018

Proton exchange membrane (PEM) water electrolysis systems offer several advantages over traditional technologies including higher energy efficiency, higher production rates, and more compact design. In this study, all the experiments were performed with a self-designed PEM electrolyser operated at 1 atm and $25^{\circ}C$. Two types of electrolyte were used: (i) potassium hydroxide (KOH), and (ii) sulfuric acid ($H_2SO_4$). In the experiments, the voltage, current, and time were measured. The concentration of the electrolyte significantly affected the electrolyser performance. Overall the best case was with 15 wt% $H_2SO_4$ at the anode channel and 20 wt% at the cathode channel with. In addition, increasing the difference in concentration of the sulfuric acid had an effect on the diffusion. The diffusion flux became larger when the difference in concentration became larger, increasing electrolyser efficiency without the addition of extra energy.

• 한국환경보건학회지
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• 제34권6호
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• pp.439-445
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• 2008

The feasibility study for the application of the removal and mineralization of Rhodamine B (RhB) was performed in a batch electrochemical reactor. The electro/UV process was consisted of DSA (dimensionally stable anode) electrode and UV-C or ozone lamp. The experimental results showed that RhB removal by the ozone lamp was higher than that of the UV-C lamp. Optimum current of the electro/UV process was 1 A. The electrochemical, UV and electro/UV process could completely degrade RhB, while a prolonged treatment was necessary to reach a high level RhB mineralization. It was observed that RhB removal in electro/UV process is similar to the sum of the UV and electrolytic decolorization. However, it was found that the COD of RhB could be degraded more efficiently by the electro/UV process (90.2 %) than the sum of the two individual oxidation processes [UV (19.7%) and electrolytic process (50.8%)]. A synergetic effect was demonstrated between the UV and electrolysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.570-571
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• 2010

To reduce the problem of ecocide, the plating equipment, water treatment system, electrolysis facility in ship need high current high power rectifier. This paper shows entire constitution of the proposed high-current rectifier for electrolysis of seawater, describes a way to design controller and analyzes output characteristic of the rectifier.

• KSBB Journal
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• 제25권1호
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• pp.25-32
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• 2010

This study was carried out to evaluate the performance of three kinds of single process (electrolysis, UV and ultrasonic process) for the purpose of disinfection of Escherichia coli in water. Among the five kinds of electrode material, disinfection performance of Ir electrode was higher than that of the other electrodes. The order of disinfection performance for E. coli in single process lies in: electrolysis > UV $\gg$ ultrasonic process. Performance of the three single processes was increased with the increase of the electric power. Disinfection efficiency of the three processes was increased with the decrease of the pH. Disinfection of the UV process were decreased by the increase of NaCl dosage and air flow rate. However, ultrasonic process was not affected above two parameters. OH radical was not produced in UV and ultrasonic process. E. coli disinfection of the electrolysis process was well agreed with RNO degradation tendency, except pH.

• 한국세라믹학회지
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• 제55권1호
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• pp.50-54
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• 2018

This study investigated the long-term durability of catalyst(Pd or Fe)-infiltrated solid oxide cells for $CO_2$/steam co-electrolysis. Fuel-electrode supported solid oxide cells with dimensions of $5{\times}5cm^2$ were fabricated, and palladium or iron was subsequently introduced via wet infiltration (as a form of PdO or FeO solution). The metallic catalysts were employed in the fuel-electrode to promote $CO_2$ reduction via reverse water gas shift reactions. The metal-precursor particles were well-dispersed on the fuel-electrode substrate, which formed a bimetallic alloy with Ni embedded on the substrate during high-temperature reduction processes. These planar cells were tested using a mixture of $H_2O$ and $CO_2$ to measure the electrochemical and gas-production stabilities during 350 h of co-electrolysis operations. The results confirmed that compared to the Fe-infiltrated cell, the Pd-infiltrated cell had higher stabilities for both electrochemical reactions and gas-production given its resistance to carbon deposition.

• 전력전자학회논문지
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• 제6권5호
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• pp.377-385
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• 2001

물을 전기분해하여 얻은 일정 부피비를 갖는 수소와 산소 혼합가스를 수산화가스로 명명하며, 이를 역반응시켜서 열 에너지원으로 사용하고 있다. 수산화가스는 경제성, 안전성 및 환경친화적인 고유한 특성을 지니고 있어서 현재 가스용접기에 적용하고 있으며 여러 가지 응용분야에 적용할 수 있도록 연구 중에 있다. 본 논문에서는 수산화가스의 특성에 관하여 고찰하고 발생기용 전원에 대하여 소개하고 이 중에서 아직까지 적용되지 않은 펄스전원을 적용하여 여러 가지 운전주파수에서 비교분석 하였다.