铁阳极在浓NaOH溶液中的极化特征  

Polarization Characteristic of Iron Anode in Concentrated NaOH Solution

作　　者：何伟春[1] 邵海波[1] 陈权启[1] 王建明[1] 张鉴清[1] 

机构地区：[1]浙江大学化学系

出　　处：《物理化学学报》2007年第10期1525-1530,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(50172041);中国科学院金属腐蚀与防护国家重点实验室资助项目

摘　　要：使用极化曲线、电解曲线对纯铁电极在浓NaOH溶液中的极化过程进行了研究.结果表明,碱溶液温度越高,碱浓度越低,电流密度越高,铁阳极越容易发生钝化;但在某些情况下,铁电极出现钝化的现象很微弱甚至观察不到.电解法制备高铁酸盐的适宜条件为,温度25-35℃,极化电流密度≤4.7mA·cm-2,碱浓度≥14.5mol·L-1.用电化学阻抗谱(EIS)研究了上述极化过程中电极表面的阻抗变化情况,据此描述了铁阳极在浓NaOH溶液中超钝化区极化时的阶段特征.Polarization curve, electrolysis curve, and electrochemical impedance spectroscopy （EIS） were adopted to study the polarization of iron electrode in the concentrated NaOH solution. The results showed that passivation of the iron anode occured more easily at higher temperature, lower alkaline concentration, and greater current density. However, the passivation phenomenon of the iron electrode might become too weak to see under some conditions. The conditions were as follows： temperature 25-35 ℃, current density ≤ 4.7 mA·cm^-2, alkaline concentration ≥ 14.5 mol·L^-1. EIS was used to investigate the impedance change of the electrode surface during the above polarization process. Next, the step characteristic of the iron anode polarization during its super-passivation range in the concentrated NaOH solution was described.

关 键 词：铁阳极 钝化 高铁酸盐 电解曲线 电化学阻抗谱 电流效率 

分 类 号：O646.54[理学—物理化学]