• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2004년도 춘계총회 및 학술발표회
• /
• pp.6-6
• /
• 2004

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

• Journal of Electrochemical Science and Technology
• /
• 제15권3호
• /
• pp.388-404
• /
• 2024

In the present work, the operating parameters were optimized using Box Behnken Design (BBD) in response surface methodology (RSM) to maximize the hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) of a proton exchange membrane electrolysis cell (PEMEC), a third response (R₃) which was the sum of the scaled values of R₁ and R₂ were selected to be maximized so that both hydrogen production rate and hydrogen production rate per unit watt consumed could be maximized. The major parameters which were influencing the experiment for enhancing the output responses were oxygen electrode/anode electrocatalyst loading (A), current supplied (B) and water inlet temperature (C). The commercial proton exchange membrane Nafion^® was used as the electrolyte. The acetylene black carbon (C_AB) supported IrO₂ was used as the electrocatalyst for preparing oxygen electrode/anode whereas commercial Pt (40 wt%)/C_HSA was used as the H₂ electrode/cathode electrocatalyst. The quadratic model was developed to predict the output/ responses and their proximity to the experimental output values. The developed model was found to be significant as the P values for both the responses were < 0.0001 and F values were greater than 1. The optimum condition for both the responses were O₂ electrode/anode electrocatalyst loading of 1.78 mg/cm², supplied current of 0.33 A and water inlet temperature of 54℃. The predicted values for hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) were 2.921 mL/min and 2.562 mL/(min·W), respectively obtained from the quadratic model. The error % between the predicted response values and experimental values were 1.47% and 3.08% for R₁ and R₂, respectively. This model predicted the optimum conditions reasonably in good agreement with the experimental conditions for the enhancement of the output responses of the developed PEM based electrolyser.

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2003년도 연료전지심포지움 2003논문집
• /
• pp.193-197
• /
• 2003

Mixture of $Ni(OH)_2-Mg(OH)_2$ used as the precurs was treated by mechnochemical(MC) and hand grinding process. Carbon nanofibers(CNF) were prepared using CVD process with the above prepared catalyst. CNFs with a uniform diameter were obtained with MC process treated catalyst, and the diameter could be controlled by tuning the grinding time. CNF bundles with close coalescence were produced with MC treated catalyst. After purification of CNFs and loading with Pt, they were used in fuel cell as the cathode catalyst support. The performance with carbon nanofibers prepared using ground mixture was found to be better than that prepared using unground mixture, which is attributed to the homogeneous CNFs with small diameter and specific interaction between Pt and CNFs.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 추계학술대회
• /
• pp.352-355
• /
• 2006

As the stainless steel has good corrosion resistance, mechanical property and ease of manufacture, it has been studied as the candidate material of metallic bipolar plate for automotive PIMFC. But, metal is dissolved under fuel cell operating conditions Dissolved ions contaminate a membrane electrode assembly (MEA) and, decrease the fuel cell performance. In addition, metal oxide formation on the surface of stainless steel increases the contact resistance in the fuel cell. These problems have been acted as an obstacle in the application of stainless steel to bipolar plate. Therefore, many kinds of coating technologies have been examined in order to solve these problems. In this study, stainless steel was coated in order to achieve high conductivity and corrosion resistance by several methods. Contact resistance was measured by using a tensile tester and impedance analyzer Corrosion characteristics of coated stainless steel were examined by Tafel-extrapolation method from the polarization curves in a solution simulating the anodic and cathodic environment of PEMFC. Fuel cell performance was also evaluated by single cell test. We tested various coated metal bipolar plate and conventional and graphite were also tested as comparative samples. In the result, coated stainless steel bipolar plate exhibited better cell performance than graphite to bipolar plate.

• 한국수소및신에너지학회논문집
• /
• 제18권4호
• /
• pp.391-398
• /
• 2007

The covalently cross-linked sulfonated polyetheretherketone (CL-SPEEK) membrane was prepared by four-step synthesis of sulfonation-sulfochlorination, partial reduction, lithiation, and cross-linking, and its electrochemical and mechanical properties were investigated for water electrolysis application. The prepared ion exchange membranes showed good electrochemical and mechanical properties; proton conductivity of 0.116 S/cm at $80^{\circ}C$, water uptake of 44.6%, ion exchange capacity of 1.75 meq/g-dry-memb., tensile strength of 64.25 MPa and elongation of 61.11%. The membrane electrode assembly (MEA) with homemade membranes were prepared by non-equilibrium impregnation-reduction (I-R) method. Especially, the electrochemical surface area (ESA) and roughness factor of CL-SPEEK electrolyte by cyclic voltammetry method were 23.46 $m^2/g$ and 307.3 $cm^2-Pt/cm^2$, respectively. The prepared MEA was used in the unit cell of water electrolysis and the cell voltage was 1.81 V at 1 A/$cm^2$ and $80^{\circ}C$, with platinum loadings of 1.31 mg/$cm^2$.