铂阳极在冰晶石-氧化铝溶液中的过电压

本文采用连续脉冲技术和电位扫描法研究了铂阳极上的过电压和反应机理,实验发现,在电流密度0.078～1.5A/cm~2的范围内过电压与电流密度的关系符合Tafel方程:η=0.22+0.21lgi (Ⅴ)此结果与Thonstad所观察的结果比较一致,但与Drassbach的数据相距较远,在实验的基础上,讨论了反应的控制步骤和反应历程,认为过电压由活化极化所引起,反应按复合脱附历程进行: 上述结论由残余电动势法和电位扫描法进一步证明,在实验中还观察到在铂阳极上也可以发生阳极效应,这在文献中还未见报道,但是铂阳极上的临界电流密度相当高,当氧化铝浓度饱和时为60A/cm~2。

Anodic Overvoltage on Platinum Electrode in Cryolyte-Alumina Melts

Overvoltage on the platinum electrode is interested as a theoretical and practical problem in the study of non-consumablly chemical inert electrode. With the positive continuous impulse technique and potential sweep voltammogram, it is found that the relationship between the values of overvoltage and current densities is a straight Tafel line and is in good agreement with those by Thonatod , as a current range from 0.078 to 1.5A/cm2 assigned. Discusses the anodic reactions on platinum electrode based on the electrode kinetic analysis, the rate-determining steps in the formation of anodic overvoltage may then be considered as a charge-tran-sfer process. It is further confirmed by the residual potential and potential sweep methods. An. anode effect is also firstly observed on platinum electrode that the critical current density is up to 60A/cm2 if saturating; the alumina concentration.