Impedance Analysis of Gas‐Diffusion Electrode Coated with a Thin Layer of Fluoro Ionomer to Enhance Its Stability in Oxygen Reduction
Impedance Analysis of Gas‐Diffusion Electrode Coated with a Thin Layer of Fluoro Ionomer to Enhance Its Stability in Oxygen Reduction
复制标题
涂有薄层氟离聚物以增强其氧还原稳定性的气体扩散电极的阻抗分析
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
K. Okajima
中科院分区：
文献类型：
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作者：
M. Sudoh;T. Kondoh;N. Kamiya;T. Ueda;K. Okajima
氧在气体扩散电极上还原的动力学已被广泛研究，但关于电极特性或电极降解机理的定量数据还不够。因此，通过改变电极的组成、聚四氟乙烯含量或Ag或Pt的催化剂种类来评价电极特性，以定量地确定电解质渗透的效果。此外，在电极表面涂覆了Nafion薄膜或等离子体聚合膜，以提高电极的稳定性。用交流阻抗法研究了氧在气体扩散电极上还原的阴极性能。电解质渗透到气体扩散电极中的效果通过使用电荷转移电阻和双电层电容定量地确定，对应于催化剂消耗和在高温下在高浓度碱性溶液中电极的界面区域中的润湿性。从与ELAT（E-TEK Co.）电极，发现带电薄膜使碱性溶液渗透到电极中最小化。
The kinetics of oxygen reduction on gas-diffusion electrodes has been extensively investigated, but quantitative data on the electrode characteristic or the mechanism of the electrode degradation are not sufficient. Therefore, electrode characteristics were evaluated by the change of the composition of the electrode, polytetrafluoroethylene content, or catalyst species of Ag or Pt to determine quantitatively the effect of the electrolyte penetration. In addition, a Nafion thin film or a plasma-polymerized film was coat-ed on the surface of the electrodes to improve the stability of the electrode. The cathodic properties of oxygen reduction on the gas-diffusion electrode were examined by the ac impedance method. The effect of the penetration of the electrolyte into the gas-diffusion electrode was determined quantitatively by using the charge-transfer resistance and the double-layer capacitance, corresponding to catalyst consumption and wettability in the interafacial area of the electrode in highly concentrated alkaline solution at high temperature. From the acceleration test with ELAT (E-TEK Co.) electrodes, the charged thin film was found to minimize the penetration of alkaline solution into the electrode.