V(IV)在不同电极上氧化还原动力学研究

Electro-Chemical Oxidation Kinetics of the V(IV) in the Sulfuric Acid Solution

分别以导电塑料集流板、石墨棒、铂片作工作电极,应用循环伏安法和稳态极化法研究V(IV)的阳极氧化动力学过程,计算V(IV)在不同材料电极上的反应动力学参数.结果表明,以导电塑料板作电极,硫酸氧钒有较宽的水稳定区,且析氧电位较高;在石墨电极上,V(V)/V(IV)的交换电流密度较大,表现出较好的可逆性;而在铂电极上,硫酸氧钒更易析氢.

The electro-chemical oxidation kinetics for V （IV） in cyclic voltammetry and steady state polarization curves at a graphi the sulfuric acid solution were investigated by re, platinum or conducting polymer electrode. Some kinetics parameters for the electrochemical reaction of V （IV） were calculated according to the Tafel curves. The results showed that the exchange current density and reversibility of V（ V）/V（IV） redox reaction at the graphite electrode is largest among the three electrodes. There is the broadest extent of water stability and large oxidgen evolution potential when the conducting polymer was used as a working electrode in the solution of VOS04（0.5 mol/L） and H2SO4（2 mol/L）, while it is easy to evolve hydrogen at a platinum electrode in the same solution.