反丁烯二酸在铅电极上的电还原特性.pdfVIP

理化学学报(Wuli Huaxue Xuebao) 1264 A cta Phys. Chim. Sin., 2008, 24(7) ：1264-1270 July [Article] 、反丁烯二酸在铅电极上的电还原特性 恒 甘永平 黄 辉 张文魁 (浙江工业大学化学工程与材料学院, 杭州 310032) 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 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 -6 -6 2 -1 数分别为7.96伊10 和6.72伊10 cm ·s . 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 中图分类号： O646 Electrochemical Reduction Behaviors of Maleic Acid and Fumaric Acid at Lead Electrode SHAO Heng GAN Yong Ping HUANG Hui ZHANG Wen Kui (College of Chemical Engineering and Materials Science, Zhej iang University of Technology, Hangzhou 310032, P. R. China) 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 irreve