物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1264-1270.doi: 10.3866/PKU.WHXB20080724

研究论文 上一篇    下一篇

顺、反丁烯二酸在铅电极上的电还原特性

邵恒; 甘永平; 黄辉; 张文魁   

  1. 浙江工业大学化学工程与材料学院, 杭州 310032
  • 收稿日期:2007-12-05 修回日期:2008-03-21 发布日期:2008-07-04
  • 通讯作者: 张文魁 E-mail:chem@zjut.edu.cn

Electrochemical Reduction Behaviors of Maleic Acid and Fumaric Acid at Lead Electrode

SHAO Heng; GAN Yong-Ping; HUANG Hui; ZHANG Wen-Kui   

  1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2007-12-05 Revised:2008-03-21 Published:2008-07-04
  • Contact: ZHANG Wen-Kui E-mail:chem@zjut.edu.cn

摘要: 采用循环伏安、计时电量及电化学阻抗等方法, 研究了顺、反丁烯二酸在铅电极上的电化学还原行为, 获取了传递系数、表观活化能和扩散系数等动力学参数, 并讨论了电化学还原机理. 结果表明, 顺、反丁烯二酸在铅电极上的电还原过程均为二电子不可逆反应, 扩散过程是速率控制步骤; 反丁烯二酸(FA)的还原电位要比顺丁烯二酸(MA)高约0.1 V, 较顺丁烯二酸难还原; 0.04 mol·L-1顺、反丁烯二酸在0.1 mol·L-1硫酸介质中的扩散系数分别为7.96×10-6和6.72×10-6 cm2·s-1. 电化学阻抗研究表明, 在铅电极上顺丁烯二酸较反丁烯二酸有更好的反应活性, 在较低偏置电压下FA和MA的电化学还原过程受电子转移控制, 随着偏置电压的增加, 逐渐转变为扩散控制. 顺丁烯二酸和反顺丁烯二酸的不同空间结构, 使顺、反丁烯二酸在铅电极表面电还原行为存在差异.

关键词: 顺丁烯二酸, 反丁烯二酸, 电化学行为, 扩散

Abstract: Electrochemical reduction characteristics of fumaric acid (FA) and maleic acid (MA) at lead electrode were investigated by voltammetry, chronocoulometry, and electrochemical impedance spectrum (EIS). The corresponding transfer coefficients, apparent energies of activation, and diffusion coefficients were calculated and the mechanism of electrochemical reduction were discussed. The experimental results showed that the electrochemical reduction of FA and MA was two-electron irreversible reaction, in which the diffusion process was the rate-determined step. The reductive potential of FA at lead was about 0.1 V higher than that of MA, indicating that FA is more difficult to be electroreduced. The corresponding diffusion coefficients for 0.04 mol·L-1 FA and MA in 0.1 mol·L-1 sulphuric acid solution were 7.96×10-6 and 6.72×10-6 cm2·s-1, respectively. The EIS results showed that charge transfer was the rate-determined step in the electroreduction processes of FA and MA at Pb electrode under low DC bias. As increase in bias potential, the diffusion process became the rate-determined step gradually. The difference in the electroreduction characteristics of FA and MA at Pb electrode was due to their different three-dimensional structure.

Key words: Maleic acid, Fumaric acid, Electrochemical behaviour, Diffusion

MSC2000: 

  • O646