乙二醇在碱性溶液中铂电极上的电化学氧化机理  

Mechanistic study of ethylene glycol oxidation on Pt electrode in alkaline solutions

作　　者：徐常威[1] 沈培康[1] 

机构地区：[1]中山大学物理科学与工程技术学院光电材料与技术国家重点实验室,广东广州510275

出　　处：《电源技术》2005年第5期282-285,共4页Chinese Journal of Power Sources

基　　金：国家十五863项目(2003AA517050);广州市科技攻关重点项目(2003Z2-D0081)

摘　　要：用电化学循环伏安法、计时电流法、计时电位法研究了乙二醇在碱性电解质中铂电极上的电化学氧化行为,探素了乙二醇在铂电极上的氧化机理。发现乙二醇在1.0mol/L乙二醇+1.0mol/LKOH水溶液中恒电流极化时产生电位振荡现象。根据机理分析,认识到乙二醇在恒电流电化学氧化过程中的电位振荡是由于乙二醇氧化产生的醛类中间产物吸附于铂电极上使其毒化造成的。乙二醇的电化学氧化是一个多电子失去过程,实验得出乙二醇在KOH水溶液中电化学氧化时失去的电子数随着电流密度或极化电位的增大而增大。根据实验结果计算得到的对称系数b是0.15,扩散系数D是1.10×10-7cm2/s。The mechanism of ethylene glycol oxidation on Pt electrode in KOH alkaline media was studied by cyclic voltammetry, chronopotentiometry, chronoamperometry. The potential oscillation phenomenon of ethylene glycol oxidation was observed, indicating the poisoning of the electrode by the adsorption of intermediates formed during the ethylene glycol oxidation. The oxidation of ethylene glycol is a multi-electron loss process and the number of the electron lost during the oxidation processes is increase with the increasing of the current density or the polarization potential. The coefficient b and D were calculated as 0.15 and 1.10×10-7 cm2/s in 1.0 mol/L ethylene glycol + 1.0 mol/L KOH according to the experimental results.

关 键 词：燃料电池 乙二醇 碱性溶液 电位振荡 

分 类 号：TM911.4[电气工程—电力电子与电力传动]