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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (8): 795-800. 上一篇    下一篇

研究论文

Keggin型缺位磷钨杂多阴离子的电化学性质及电催化还原过氧化氢

华英杰a 王崇太*,a,b 李高仁c 童叶翔c 李玉光c

  

  1. (a海南师范大学化学与化工学院 海口 571158)
    (b海南省热带药用植物化学重点实验室 海口 571158)
    (c中山大学化学与化工学院 广州 510275)

  • 投稿日期:2008-04-03 修回日期:2008-11-19 发布日期:2009-04-28
  • 通讯作者: 王崇太

Electrochemical Properties of the Keggin-type Lacunary Heteropolytungstate Anion and Its Electrocatalysis for H2O2 Reduction

Hua, Yingjie a Wang, Chongtai *,a,b Li, Gaoren c Tong, Yexiang c Li, Yuguang c   

  1. (a School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158)
    (b Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, Haikou 571158)
    (c School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275)
  • Received:2008-04-03 Revised:2008-11-19 Published:2009-04-28
  • Contact: Wang, Chongtai

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被引次数

32 | 6

循环伏安实验显示, 缺位磷钨杂多阴离子 的酸性水溶液在玻碳(GC)电极上有两对可逆的还原-氧化波. 第一对波的电荷迁移数为1.4, 有2个质子参与反应; 第二对波的电荷迁移数为1.0, 参加电极反应的质子数为1. 根据峰电流与电位扫描速率平方根的关系得到 在0.1 mol•L－1 NaOAc＋HOAc溶液中的扩散系数 Do为3.54×10－6 cm2•s－1. 交流伏安和交流阻抗实验表明, 的电极过程包含吸附和脱附步骤, 第一对波的电荷迁移阻抗较大, 第二对波的较小, 对应的交换电流密度i0分别为4.6×10－5和6.7×10－4 A•cm－2. 电极过程的可逆性及其缺位特性使它对H2O2的还原有显著的电催化作用, 因此有望用于有机物的氧化和降解. 同时, 还提出了一个相关的电催化机理.

关键词: 缺位磷钨杂多酸盐, 电催化, 过氧化氢, 循环伏安, 交流阻抗

Cyclic voltammograms indicated that two reversible redox waves were observed on the glassy carbon (GC) electrode in acidic aqueous solution containing . The first wave involves in 1.4 electron transfer and two protons during electrode reaction, and one electron and one proton are for the second wave. Diffusion coefficient Do of calculated from linear relationship of peak current versus square root of potential scan rate is 3.54×10－6 cm2•s－1 in a solution of 0.1 mol•L－1 NaOAc＋HOAc (pH 3.5). Alternating current (AC) voltammetry and AC impedance revealed that an adsorption of on the electrode surface occurred before electron transfer, which caused larger electron transfer impedance in the first wave than in the second wave. The exchange current density i0 corresponding to the first wave and the second wave is 4.6×10－5 and 6.7×10－4 A•cm－2, respectively. A reversible electrochemical property and a lacunary feature of make it electrocatalyze efficiently reduction of H2O2 in acidic aqueous solution. The system of /H2O2 thus represents a possible application to electrocatalytic oxidation of organic substrates. Also a novel catalytic mechanism was proposed.

Key words: lacunary heteropolytungstate, electrocatalysis, hydrogen peroxide, cyclic voltammetry, AC impedance