摘要
平衡电极电势实验确定了25℃时石墨电极在1.5 mol/L醋酸钾+(醋酸-醋酐)(3∶1体积比)溶液中Mn(Ⅲ)/Mn(Ⅱ)的条件电极电势为0.720 V(vsSCE);采用电势扫描和旋转圆盘电极技术研究了醋酸-醋酐溶液中石墨电极上Mn(Ⅲ)/Mn(Ⅱ)电对的阳极氧化动力学,结果表明:Mn(Ⅱ)阳极氧化成Mn(Ⅲ)的电极反应控制步骤属扩散-电荷传递混合控制过程,阳极传递系数β=0.183,交换电流密度i0=5.80×10-5A/cm2,阳极标准反应速度常数ka=9.16×10-8m/s,Mn(Ⅱ)和OAc-的反应级数均为一级。
The electrochemical behavior of Mn （ Ⅲ ）/Mn （ Ⅱ ） on graphite electrode in acetic-acid-anhydride was investigated .The result of equilibrium potential showed that the conditional electrode potential of Mn（ Ⅲ ）/Mn（ Ⅱ ） was 0.720 V（ vs SCE）. The results of linear sweep polarization curve and RDE on graphite electrode showed that the rate determining step of the electrode process was a combined process of diffusion and charge-transfer. The anodic charge-transfer kinetic parameters were determined. The anodic charge-transfer coefficient is O. 183, the exchange current density io is 5.80 × 10^-5A/cm^2 ,and the conditional charge-transfer rate constant k, is 9.16 × 10^-5 m/s under 25℃ .The reaction is first order in Mn（ Ⅱ ）and also first order in OAc^-.
出处
《化学世界》
CAS
CSCD
北大核心
2007年第3期129-131,147,共4页
Chemical World
基金
广东省科技计划资助项目(2004B10301010)
