高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (5): 864-871.doi: 10.7503/cjcu20141148

• 分析化学 • 上一篇    下一篇

修饰铂阳极上氯离子对4种有机醇电氧化反应的阻化作用

马永钧(), 丁静, 金芝梅, 铁珍珍, 周敏   

  1. 甘肃省生物电化学与环境分析重点实验室, 西北师范大学化学化工学院, 兰州 730070
  • 收稿日期:2014-12-31 出版日期:2015-05-10 发布日期:2015-04-16
  • 作者简介:联系人简介: 马永钧, 男, 博士, 教授, 主要从事电分析化学研究. E-mail: mayj@nwnu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21167015)资助

Inhibiting Effect of Chloride Ion for the Electro-oxidation Reaction of Four Organic Alcohols on a Chemically Modified Platinum Anode

MA Yongjun*(), DING Jing, JIN Zhimei, TIE Zhenzhen, ZHOU Min   

  1. Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province,College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
  • Received:2014-12-31 Online:2015-05-10 Published:2015-04-16
  • Contact: MA Yongjun E-mail:mayj@nwnu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21167015)

摘要:

采用循环伏安法和计时电流法, 分别在裸铂电极和聚缬氨酸/含稀土氰桥混合配位聚合物化学修饰铂(Poly-valine/Nd-Fe-Mo CyMCP/Pt)电极上定量研究了支持电解质中氯离子对甲醇、 乙醇、 正丙醇和异丙醇4种有机醇阳极氧化伏安特性的影响. 结果表明, 在弱酸性介质中, 无论在裸铂电极或修饰铂电极上, 电解液中的氯离子对4种醇的阳极氧化反应均可产生阻化作用. 当阻化作用显著发生时, 相应氯离子的临界浓度均介于10-5~10-6 mol/L之间, 说明铂阳极上氯离子的足量吸附是导致4种醇电极氧化反应被阻化的主要原因. 此外, 通过讨论氯离子浓度变化对4种醇正、 反扫描过程中不同氧化峰电流间比值及计时电流曲线的影响, 初步证明在4种有机醇分子涉及生成CO及CO2产物的氧化反应步骤与涉及生成其它氧化产物的反应步骤之间, 氯离子的阻化作用存在明显差异.

关键词: 氯离子, 电催化氧化, 有机醇, 化学修饰电极

Abstract:

On a bare platinum electrode and the chemically modified platinum electrode coated with poly-valine/3d-4f hybrid-metal cyano-bridged mixing coordination polymer(poly-valine/Nd-Fe-Mo CyMCP/Pt), the effect of chloride ion in supporting electrolyte on the voltammetric behavior of electro-oxidation reaction of methanol, ethanol, n-propanol and iso-propanol was quantitatively studied by cyclic voltammetry and chronoamperometry. The results showed that whether on a bare platinum anode or the modified platinum anode, there existed the inhibiting effect of the chloride ion on the four alcohols’ anodic oxidation reaction in the weak acidic medium. The inhibiting effect of chloride ion would become remarkable once the concentration of chloride ion exceeded the critical value between 10-5—10-6 mol/L region, the experiment results proved that the abundant adsorption of chloride ion at a platinum anode was the main reason leading to produce inhibition effect for four organic alcohols. In addition, by discussing the influences of chloride ion concentration on the value of some oxidative peaks’ current ratio in positive-going scan to negative-going scan and the variety of chronoamperometry curves for the anodic oxidation process of four alcohols, it was preliminarily deduced that the inhibiting degree of chloride ion had been significantly different when being acted on the electro-oxidation steps involved CO and CO2 product formation or the electro-oxidation steps involved other product formation in the entire electrooxidation process of four alcohols.

Key words: Chloride ion, Electro-catalytic oxidation, Organic alcohol, Chemically modified electrode

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