物理化学学报 >> 2003, Vol. 19 >> Issue (06): 569-572.doi: 10.3866/PKU.WHXB20030619

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Pd/Mm(富铈稀土)薄膜电极在KOH溶液中的电化学行为

张文魁;杨晓光;王云刚;余厉阳;马淳安   

  1. 浙江工业大学应用化学系,杭州 310014;浙江大学材料与化工学院,杭州 310027
  • 收稿日期:2002-10-07 修回日期:2003-02-24 发布日期:2003-06-15
  • 通讯作者: 张文魁 E-mail:echem@zjut.edu.cn

Electrochemical Behaviors of Pd/Mm Rare Earth Film Electrodes in KOH Solution

Zhang Wen-Kui;Yang Xiao-Guang;Wang Yun-Gang;Yu Li-Yang;Ma Chun-An   

  1. Department of Applied Chemistry,Zhejiang University of Technology,Hangzhou 310014;
  • Received:2002-10-07 Revised:2003-02-24 Published:2003-06-15
  • Contact: Zhang Wen-Kui E-mail:echem@zjut.edu.cn

摘要: 利用磁控溅射法制备了Pd/Mm(Mischmetal)混合稀土薄膜,采用X射线衍射、AFM及循环伏安和交流阻抗谱等电化学测试技术研究了Pd/Mm稀土薄膜的晶体结构、表面形貌及其在KOH溶液中的电化学行为.结果表明,Pd/Mm薄膜表面的Pd层由纳米级的孤岛状颗粒构成,颗粒大小为100~200 nm.循环伏安法研究表明,氢的电化学氧化和还原均通过表面Pd金属层进行.Pd/Mm稀土薄膜电极的交流阻抗图由两个容抗弧组成,低频区的容抗弧对应氢在电极中的固态扩散过程,而高频段的容抗弧对应氢在电极表面的电化学还原过程,其中氢在薄膜电极内部的扩散是速率控制步骤.

关键词: 稀土薄膜, 电化学行为, 循环伏安, 交流阻抗, 富铈稀土(Mm)

Abstract: Pd/Mm(mischmetal) rare earth films were prepared by magnetron sputtering technology,the crystal structure,morphology and electrochemical behavior of the asprepared films were investigated by using XRD,AFM and electrochemical measurement techniques including cyclic voltammetry and AC impedance.The results showed that Pd coatings is a kind of island structure with 30~50 nm in size.The electrochemical reduction or oxidation of hydrogen only occurred on the Pd coatings.The electrochemical impedance spectra of Pd/Mm film electrodes was composed of two semicircles,of which the low frequency zone is corresponded to the solid diffusion process of H atom in the film,and the high one to the electrochemical reaction on the surface of the electrode.The solid diffusion process of H atom in the inner rare earth layer is the ratecontrolled step.

Key words: Rareearth films, Electrochemical characteristics, Cyclic voltammetry