• 한국수소및신에너지학회논문집
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• 제8권2호
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• pp.51-56
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• 1997

Laves상 $ZrV_2$합금은 다량의 수소를 저장하지만 수소와의 결합력이 강하여 Ni-MH전지의 전극으로는 부적당하다. 전극에 응용하기 위해 $ZrV_2$합금중의 V의 일부를 Ni로 치환하여 수소와의 결합력을 약하게 하였다. 이와 같은 Zr-V-Ni계 합금에 대해 전기화학적 성질, 전극의 평형전위로부터 합금중의 수소의 열역학적성질 및 2차전지전극에의 응용가능성을 조사하였다.

• 전기화학회지
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• 제8권1호
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• pp.47-54
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• 2005

This article covers the fundamentals of stress-induced diffusion, focusing on the theoretical model for hydrogen transport through self-stressed electrode. First, the relationship between hydrogen diffusion and macroscopic deformation of the electrode specimen was briefly introduced, and then it was classified into the diffusion-elastic and elasto-diffusive phenomena. Next, the transport equation for the flux of hydrogen caused simultaneously by both the concentration gradient and the stress gradient was theoretically derived. Finally, stress-induced diffusion was discussed on the basis of the numerical solutions to the derived transport equation under the permeable and impermeable boundary conditions.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1227-1228
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• 2006

The electrochemical properties of novel metal powders were investigated for the electrode materias of polymer electrolyte memebrane electrolysis. Two types of Pt black and $IrO_2$ powder electrodes were hot-pressed on the polymer electrolyte membrane to form membrane electrode assembly. The galvanodynamic polarization methode was used to characterize the electrochemical properties of both electrodes. From the experimental results, we concluded that the $IrO_2$ powder electrode exhibits better electrochemical performance than Pt black as cathode material for the electrolysis.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1565-1568
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• 2005

A surface renewable pH electrode was prepared by utilizing composite electrode technique. Iridium oxide micro-fine particles was prepared by hydrolysis of $(NH_4)_2IrCl_6$ at elevated temperature. The iridium oxide particles were mixed with well-dispersed carbon black and then filtered. The mixture was suspended in DMF containing PVC as a binder. The mixture was precipitated rapidly by adding large amount of water. The precipitate was ground and pressure-molded to iridium oxide composite electrode material. The electrode showed linear response between pH 1-13 with 50 to 60 mV/pH slope. The electrode maintained the pH response without appreciable slope drift for 170 days if stored in deionized water. The electrode surface can be renewed reproducibly by simple grinding process whenever contaminated or deactivated.

• 전기화학회지
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• 제16권1호
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• pp.30-38
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• 2013

In this study, a catalyst slurry was prepared with a Pt/C catalyst, Nafion ionomer solution as a binder, an ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate), deionized water and ethanol as a solvent for the application to polymer electrolyte fuel cells (PEFCs) at high-temperatures. The effect of the IL in the electrode of each design was investigated by performing a cyclic voltammetry (CV) measurement. Electrodes with different IL distributions inside and on the surface of the catalyst electrode were examined. During the CV test, the electrochemical surface area (ESA) obtained for the Pt/C electrode without ILs gradually decreased owing to three mechanisms: Pt dissolution/redeposition, carbon corrosion, and place exchange. As the IL content increased in the electrode, an ESA decrement was observed because ILs leaked from the Nafion polymer in the electrode. In addition, the CVs under conditions simulating leakage of ILs from the electrode and electrolyte were evaluated. When the ILs leaked from the electrode, minor significant changes in the CV were observed. On the other hand, when the leakage of ILs originated from the electrolyte, the CVs showed different features. It was also observed that the ESA decreased significantly. Thus, leakage of ILs from the polymer electrolyte caused a performance loss for the PEFCs by reducing the ESA. As a result, greater entrapment stability of ILs in the polymer matrix is needed to improve electrode performance.

• 에너지공학
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• 제24권2호
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• pp.34-39
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• 2015

본 연구에서는 중온에서 수소생산이 가능한 무격막형 알칼리수전해 장치를 제작하여 전극재질에 따른 수소생산 특성을 확인하였다. 전극재질($IrO_2/Ti$, $RuO_2/Ti$, Ti)별 전기화학적 특성을 확인한 결과 $RuO_2/Ti$에서 가장 높은 효율을 나타내었고, 전해질 농도별 수소생산량 실험 결과, 전해질 농도와 수소생산량은 비례하는 경향을 보였으며 30% KOH 조건에서 $118.9m^3/m^3/day$로 가장 높은 수소생산량을 확인할 수 있었다. 전극재질별 수소생산량을 확인한 실험에서는 anode($IrO_2/Ti$)와 cathode($RuO_2/Ti$)로 조합 시 $157.55m^3/m^3/day$로 $IrO_2/Ti$를 cathode로 조합한 결과에 비해 약 6.97% 높은 수소생산량을 보였다. 이는 DSA전극의 전기화학적 활성도 향상에 의한 수소생산량 증대와 기존 전극에 비해 내구성이 향상되어 안정적인 알칼리 수전해가 가능한 것으로 사료된다.

• 공업화학
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• 제25권5호
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• pp.538-543
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• 2014

시판 고추냉이 과산화효소를 대치하기 위하여 탄소반죽에 담배 잎을 고정시켜 과산화수소 감응 센서를 제작하고 그것의 감응성을 살펴보았다. 얻어진 10여 개 이상의 전극 파라미터는 효소전극이 실험 전위영역에서 정량적으로 특이성을 발휘하고 있음을 보여주었다. 특히 작은 대칭인자(${\alpha}$, 0.21)는 전극반응 속도가 전극전위의 변화에 매우 민감한 것을 보여주었다. 이런 실험적 사실들은 효소전극이 과산화수소 센서로서 정상적으로 기능을 발휘하고 있으며 담배 과산화효소가 시판 효소를 대체할 수 있음을 보여주는 것이었다.

• Transactions on Electrical and Electronic Materials
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• 제6권5호
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• pp.214-220
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• 2005

The ferroelectric properties of the $Pt/PZT(Pb(Zr,Ti)O_3)/Pt$ capacitors are severely degraded when they are annealed in hydrogen-containing environment. Hydrogen atoms created by the catalytic reaction of Pt top electrode during annealing in hydrogen ambient penetrate into PZT films and generate oxygen vacancies by the reduction of the PZT films, which is likely to cause the degradation. The degree of hydrogen-induced degradation and the direction of voltage shift in P-E curves of the pre-poled PZT capacitors after annealing in hydrogen ambient is dependent on the polarity of the pre-poling voltage. This implies that oxygen vacancies causing hydrogen induced degradation are generated by hydrogen ions having a polarity. The degraded ferroelectricity of the PZT capacitors can be effectively recovered by the shift of oxygen vacancies toward the Pt top electrode interface during post-annealing in oxygen environment with applying negative unipolar stressing.

• 한국환경보건학회지
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• 제34권2호
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• pp.175-182
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• 2008

This study investigates the optimal conditions for electrogenerated hydrogen peroxide production and the application of the electro-Fenton process using DSA electrodes. The influences of parameters for the hydrogen peroxide generation such as electrode materials, electrolyte concentration, current, pH, air flow rate and electrode distance were investigated using a laboratory scale batch reactor. The relative performance for hydrogen peroxide generation of each of the six electrodes is : Ru-Sn-Ti > Ru-Sn-Sb > Ru > Ir > Pt > Sn-Sb. Optimum NaCl dosage, current and air flow rate were 2.0 g/l, 12.5 A and 2 l/min, respectively. When the pH is low, hydrogen peroxide concentration was high. Electrode distance dos not effect to a hydrogen peroxide generation. A complete color removal was obtained for RhB (200 mg/l) at the 8 min mark of the electro-Fenton process under optimum operation conditions of $Fe^{2+}$ 0.105 g/l and 5.0 A. The electro-Fenton process increased initial reaction and decreased final reaction time. However the effect was not high.

• 한국응용과학기술학회지
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• 제27권4호
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• pp.415-420
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• 2010

This study is focused on the channel design of bipolar plate in the electrode of hydrogen gas generator. The characteristics of hydrogen gas generation was studied in view of efficiency of hydrogen gas generation rate and a tendency of gas flow through the riv design of electrode. Since the flow rate and flow pattern of generated gas in the two phase flow system are the most crucial in determining the efficiency of hydrogen gas generator, we adopted the commercial analytical program of COMSOL MultiphysicsTM to calculate the theoretical flow rate of hydrogen gas from the outlet of gas generator and flow pattern of two phase fluid in the electrode. In this study, liquid electrolyte flows into the bipolar plate and decomposed into gas phase, two phase flow simulation is applied to measure the efficiency of hydrogen gas generation.