• Korean Chemical Engineering Research
• /
• 제51권3호
• /
• pp.325-329
• /
• 2013

실제 고분자 전해질 연료전지(PEMFC) 운전조건에서는 전극과 전해질 막은 동시에 열화된다. 그런데 고분자전해질 연료전지의 전극 열화와 전해질 열화의 상호 작용에 대해 연구되지 않았다. 본 연구에서는 전해질 막 열화가 전극 열화에 미치는 영향에 대해 연구하였다. 전해질 막 열화 후 전극을 열화시켜 전해질 막 열화없이 전극을 열화시켰을 때와 비교하였다. 열화전후의 I-V 성능, 수소투과전류, 순환 전압측정(CV), 임피던스, TEM 등을 측정하였다. 전해질 막열화에 의해 수소투과도가 증가하고, 이에 따라 백금 입자 성장속도가 감소함으로써 전극 열화속도가 감소함을 보였다.

• 마이크로전자및패키징학회지
• /
• 제11권4호
• /
• pp.87-91
• /
• 2004

[ $Sr_{0.8}Bi_{2.4}Ta_2O_9(SBT)/Pt$ ] 구조에서 $350^{\circ}C$ 온도로 수소열처리에 의한 강유전특성 열화를 방지하기 위한 W-N/Pt 하부전극의 효과를 살펴보았다. 그 결과 Pt와 SBT 박막사이에 증착된 W-N박막에 의해 수소의 확산을 차단할 수 있었다. Pt 표면에서 수소원자가 화학적인 흡착이 일어나지 않음으로써 흡착된 수소가 SBT 박막내의 산소와 결합하게 됨으로써 oxygen deficiency가 발생하는 것을 막을 수 있었다. W-N 박막이 양호한 확산방지막으로 작용하여 강유전특성의 열화현상을 방지 할 수 있었다.

• 한국수소및신에너지학회논문집
• /
• 제4권2호
• /
• pp.23-28
• /
• 1993

The $(LM)Ni_{4.5}Co_{0.1}Mn_{0.2}Al_{0.2}$ hydrogen storage alloy powders were conducted 25wt% electroless copper plating in an acidic bath. For the preparation of a hydride electrodes, the copper coated alloy powder was mixed with Si-sealant(organosilicon) and compacted with $6t/cm^2$ at room temperature. The electrode characteristics were examined through electrochemical measurements in a half cell. As a sealant contents increased, the initial discharge capacity of si-sealant bounded electrode was lower and the activation rate in high current density was slower. For extended cycles, however, the electrodes with the Si-sealant were superior in a high rate discharge and useful range of temperature over the sealant-free electrode. In addition, the cycle life increased with increasing the amount of Si-sealant added. It can be suggested from the results that the Si-sealant as a binder could be applied to the preparation of the metal hydride electrode.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2015년도 춘계학술대회 논문집
• /
• pp.101-101
• /
• 2015

Photoelectrochemical water splitting is considered as a promising method of transforming solar energy into chemical energy stored in the type of hydrogen. An n-type $WO_3$ semiconductor is one of the most promising photoanodes for hydrogen production from water splitting. Films annealed at lower temperatures consisted of amorphous, whereas films annealed above $500^{\circ}C$ comprised solely of monoclinic $WO_3$. In this study, we observed photoactivity of $WO_3$ as increasing thickness of $WO_3$. And it shows good photoacivity as thickness increases. Also we tried to improve photoactivity through surface modification and bulk modification by using hydrogen treatment and conducting polymer. The photocurrent was measured in potentiostatic method with the three electrode system. A Pt wire and Ag / AgCl electrode were used as the counter electrode and the reference electrode, respectively. photocurrent-time (I-T) curve was measured at a bias potential of 0.79 V.

• 전기전자학회논문지
• /
• 제22권2호
• /
• pp.356-361
• /
• 2018

고온에서 이용 가능한 수소 센서에 관해 연구하였다. 센서는 $Pd/Ta_2O_5/SiC$으로 구성된 MOS 구조로 제작되었으며, $Ta_2O_5$ 박막은 급속 열 산화법(RTO)법으로 형성하였다. 본 연구에서는 3가지 다른 패턴의 팔라듐(Pd) 전극으로 만든 센서를 제작하여, Pd 전극의 형태가 응답 특성에 미치는 영향을 고찰하였다. 그 결과, 센서는 Pd 전극의 채워진 면적이 클수록, 정전용량의 응답특성이 개선됨을 확인하였다.

• Nuclear Engineering and Technology
• /
• 제55권10호
• /
• pp.3659-3664
• /
• 2023

The electrochemical behavior of dissolved hydrogen (H₂) was investigated at a Pt electrode in a high temperature LiOH-H₃BO₃ solution. The diffusion current of the H₂ oxidation was proportional to the concentration of the dissolved H₂ as well as the reciprocal of the temperature. In the polarization curve, a potential region in which the oxidation current decreases despite an increase in the applied potential between the H₂ oxidation and the water oxidation regions was observed. This potential region was interpreted as being caused by the formation of a Pt oxide layer. Using the properties of the Cl^- ion that reduces the growth rate of the Pt oxide layer, it was confirmed that there is a correlation between the Cl^- ion concentration and the transient current of the H₂ oxidation.

• 분석과학
• /
• 제12권2호
• /
• pp.125-129
• /
• 1999

고농도의 과산화수소(10-75%)를 생산현장에서 손쉽게 측정할 수 있는 전극 센서 시스템을 연구하였다. Teflon 전극체는 휴대에 간편하도록 길이 10 cm, 지금 1.5 cm의 봉 형태로 제작하였고, 작업 극으로는 직경 3 mm의 glassy carbon을, 보조전극으로는 내경 5 mm, 외경 9 mm의 흑연을 전극물질로 사용하였다. 과산화수소 산화전위는 0.8 V의 전위를 걸어주었다. 공장에서 생산된 고농도의 과산화수소를 일정 이온강도의 전해질 용액으로 희석해 10% 이하의 농도가 되도록 하면 과산화수소에 첨가된 안정제의 방해작용과 과산화수소의 산화작용으로 인한 전극표면의 변성을 최소화할 수 있었고, 손쉽게 정량적인 측정을 할 수 있었다. 또한 과산화수소 투과막(teflon membrane${\leq}100{\mu}m$)을 입힌 전극을 이용하면 고농도의 과산화수소를 희석하지 않고 재현성 있게 정량할 수 있었다. 반면 투과막을 이용하는 방법을 내부전해질을 자주 교환해야 하는 단점이 있었다.

• 한국수소및신에너지학회논문집
• /
• 제30권6호
• /
• pp.523-530
• /
• 2019

For the low-Pt electrodes for polymer electrolyte fuel cells (PEMFCs), the optimization of ionomer content for anode catalyst layers was carried out. A commercial catalyst of 20 wt.% Pt/C was used instead of 50 wt.% Pt/C which is commonly used for PEMFCs. The ionomer content varies from 0.6 to 1.2 based on ionomer to carbon ratio (I/C) and the catalyst layer is formed over the electrolyte by the ultrasonic spray process. Evaluation of the prepared MEA in the unit cell showed that the optimal ionomer content of the air electrode was 0.8 on the I/C basis, while the hydrogen electrode was optimal at the relatively high ionomer content of 1.0. In addition, a large difference in cell performance was observed when the ionomer content of the hydrogen electrode was changed. Increasing the ionomer content from 0.6 to 1.0 by I/C in a hydrogen electrode with 0.05 mg/㎠ platinum loading resulted in more than double cell performance improvements on a 0.6 V. Through the analysis of various electrochemical properties in the single cell, it was assumed that the change in ionomer content of the hydrogen electrode affects the water flow between the hydrogen and air electrodes bounded by the membrane in the cell, which affects the overall performance of the cell. A more specific study will be carried out to understand the water flow mechanism in the future, and this study will show that the optimization process of hydrogen electrode can also be a very important cell design variable for the low-Pt and high-performance MEA.

• 대한화학회지
• /
• 제59권6호
• /
• pp.554-559
• /
• 2015

• 분석과학
• /
• 제20권1호
• /
• pp.49-54
• /
• 2007

For the practical use as a biosensor, a rubber electrode bound by polybutadiene was newly devised for the determination of hydrogen peroxide. Then its electrochemical behaviors were investigated. The signal could be obtained at low electrode potential between 0.0 ~ -0.5 V (vs. Ag/AgCl) with a detection limit of $1.4{\times}10^{-4}M$ and its potential dependence was linear in the experimental range. Especially its Lineweaver-Burk plot showed a very good linearity giving the evidence of a good enzyme immobilization on the surface of the electrode. And mechanical stability of the electrode resulted from using rubber binder presented a new possibility for the practical use of biosensor.