高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (11): 2151.

• 研究论文 • 上一篇    下一篇

多壁纳米碳管空气电极的交流阻抗研究

黄辉1, 张文魁1, 马淳安1, 葛忠华1, 卢焕明2, 张孝彬2   

  1. 1. 浙江工业大学应用化学系, 杭州310014;
    2. 浙江大学材料科学与工程系, 杭州310027
  • 收稿日期:2001-05-30 出版日期:2002-11-24 发布日期:2002-11-24
  • 通讯作者: 黄　辉(1971年出生),男,博士研究生,从事催化新材料及电催化研究.
  • 基金资助:

    国家自然科学基金(批准号:59872030);浙江省自然科学基金(批准号:299502);浙江工业大学工程研究中心资助

AC Impedance Studies on Multi-walled Carbon Nanotubes Air Electrode

HUANG Hui1, ZHANG Wen-Kui1, MA Chun-An1, GE Zhong-Hua1, LU Huan-Ming2, ZHANG Xiao-Bin2   

  1. 1. Department of Applied Chemistry, Zhejiang University of Technology, Hangzhou 310014, China;
    2. Department of Materials Science and Technology, Zhejiang University, Hangzhou 310027, China
  • Received:2001-05-30 Online:2002-11-24 Published:2002-11-24

PDF (PC)

被引次数

63

摘要： 研究了多壁纳米碳管、活性炭和石墨等空气电极的交流阻抗特性.结果表明,纳米碳管空气电极的阻抗谱由两个半圆组成,高频区半圆对应欧姆极化阻抗,低频区半圆对应电化学极化阻抗.催化剂Pt以纳米颗粒的形式沉积在碳管的外表面,明显减小了电极的欧姆阻抗和电化学极化阻抗,提高了氧还原反应的电催化活性.活性炭电极除存在电化学阻抗外,还存在薄液膜扩散阻抗(Nernst扩散),石墨电极形成的薄液膜反应区域较小,电极反应呈Warburg扩散阻抗特征,相应的电催化活性较低.采用交流阻抗等效电路分析方法,对拟合的动力学数据进行了解释.

关键词: 纳米碳管, 空气电极, 交流阻抗, 氧还原反应

Abstract: The AC impedance properties of the air electrodes using multi-walled carbon nanotubes, active carbon and graphite particles as catalyst layer material were investigated. The results showed that the AC impedance diagram of carbon nanotubes consisted of two semi-circles, in which the high frequency zone was ascribed to the ohmic process within porous structure and the low frequency zone to the kinetic impedance of electrochemical reaction. The Pt nanoparticles deposited on the exterior surface of carbon nanotubes decreased greatly ohmic and electrochemical impedance, so increased electro-catalytic activity of oxygen reduction. However, for the air electrode prepared by active carbon, the thin film diffusion impedance was appreciably observed in addition to ohmic impedance. The low catalytic activity in the graphite air electrode appeared as a consequence of the decreased thin film reaction sites and the mass transport process was dominated by Warburg diffusion. Finally, the equivalent circuit of air electrode was proposed and the simulated kinetic data were also discussed.

Key words: Carbon nanotubes, Air electrode, AC impedance, Oxygen reduction

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