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电化学(中英文) ›› 2013, Vol. 19 ›› Issue (2): 141-145.  doi: 10.61558/2993-074X.2105

• 研究论文 • 上一篇    下一篇

Ce3+/Ce4+电对在硫酸和甲磺酸介质中电化学性能的差异

李照华,褚有群,马淳安*   

  1. 浙江工业大学 绿色化学合成技术国家重点实验室培育基地,浙江 杭州 310014
  • 收稿日期:2012-02-14 修回日期:2012-03-21 出版日期:2013-04-28 发布日期:2012-03-30
  • 通讯作者: 马淳安 E-mail:science@zjut.edu.cn
  • 基金资助:

    浙江省研究生教育创新基地基金项目(No. 1001)资助

A Comparative Study of Ce3+/Ce4+ Redox Couple on Pt Electrode in Sulfuric Acid and Methanesulfonic Acid

LI Zhao-hua, CHU You-qun, MA Chun-an*   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, China
  • Received:2012-02-14 Revised:2012-03-21 Published:2013-04-28 Online:2012-03-30
  • Contact: MA Chun-an E-mail:science@zjut.edu.cn

摘要: 采用循环伏安法和线性扫描法研究了硫酸和甲磺酸介质中Ce3+/Ce4+在Pt旋转圆盘电极(RDE)上的电化学性能,初步探索了Ce3+/Ce4+的络合行为,考察了Ce3+反应的交换电流密度、扩散系数以及反应速率常数,比较了两种酸介质中Ce3+在Pt电极氧化的活化能. 结果表明,硫酸介质中以Ce4+的络合为主,其平衡电位负移;甲磺酸介质中以Ce3+的络合为主,其平衡电位正移. 硫酸介质中Pt电极上Ce3+更容易氧化为Ce4+, 硫酸铈(III)的电氧化对温度更为敏感.

关键词: 交换电流密度, 扩散系数, 反应速率常数, 阳极氧化, 活化能

Abstract: The electrochemical oxidations of Ce3+ to Ce4+ on Pt rotating disk electrode (RDE) in both sulfuric acid and methanesulfonic acid (MSA) solutions were studied by using cyclic voltammetry and linear sweep voltammetry. The complexing behaviors of Ce3+/Ce4+ were preliminarily probed and the exchange current density, diffusion coefficient, as well as reaction rate constant were obtained from Butler-Volmer equation. The activation energies of Ce3+ oxidation on Pt electrode in two types of acidic media, obtained from Arrhenius equation, were also compared. The results indicate that Ce3+ can be oxidized to Ce4+ much easier in sulfuric acid than in MSA solutions. The equilibrium potential in sulfuric acid solutions moves negatively due to the predominant complexation of Ce4+, while that in MSA solutions positively because of the predominant complexation of Ce3+, The larger values of activation energy for the oxidation of Ce3+ to Ce4+ on Pt electrode in sulfuric acid solutions suggest that the oxidation of Ce3+ occurs more readily and the electro-oxidation of cerous sulfate is more susceptible to temperature.

Key words: exchange current density, diffusion coefficient, rate constant, anode oxidation, activation energy

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