硫酸溶液中铈离子对铅钙合金电极/电解液界面电化学特性的影响

The influence of cerium ions in sulfuric acid solution on the electrochemical performance of the lead-calcium alloy electrode/electrolyte interface

采用线性电位扫描法、循环伏安法和交流阻抗法研究了含有不同浓度硫酸铈的硫酸溶液中铅钙合金电极/电解液界面的电化学特性。实验结果表明,铅钙电极在添加Ce3+的硫酸溶液中测定的铅-钙电极/电解液界面的电化学特性同铈与铅钙合金形成的铈铅钙合金在相同浓度的硫酸溶液中得到的铈铅钙合金电极/硫酸溶液的界面具有相同的影响规律和特性。在硫酸溶液中添加铈离子,铅氧化反应电位正移;铈离子的存在提高了电极的析氧反应过电位,抑制了铅钙合金电极上氧化膜中高电阻Pb(Ⅱ)的生成,提高了氧化膜的导电性;同时也降低了铅钙合金电极的腐蚀速率,改善了PbSO4/PbO2转化反应的可逆性。随着铈离子浓度的增加,铅氧化反应的电位正移量、析氧反应的过电位增加量增加,铅钙合金电极的腐蚀速率降低量增加,PbSO4/PbO2转化反应的可逆性进一步改善。

The influence of cerium ion in sulfuric acid solution on electrochemical properties of the lead-calcium alloy electrode electrolyte/interface was studied by linear sweep voltammetry,cyclic voltammetry and impedance-time curves.The experimental results show that the affecting role and effect of the cerium ion added in sulfuric acid solution on the performance at the electrode/electrolyte interface is the same as that the of metal cerium added in lead-calcium to form cerium-calcium-lead alloy in sulfuric acid solution.The cerium ion added in sulfuric acid solution can effectively improve the electrochemical performance at the lead-calcium alloy/electrolyte interface.The oxidation potential of the lead moved to positive,the cerium ion added in sulfuric acid solution can inhibit the corrosion of the lead-calcium alloy in sulfuric acid solution,more effectively inhibit the growth of the anodic PbO2 film,and reduce the impedance of the anodic corrosion layer（PbO2） formed on the lead-calcium alloy when the addition of cerium ion in sulfuric acid solution.The over potential of hydrogen evolution reaction on the electrode when the existence of cerium ion in sulfuric acid solution is higher than that in sulfuric acid solution,the high resistance of oxide film Pb（Ⅱ） generation rate formed on the lead-calcium alloy surface can be inhibited by the oxidation of the lead is lower,the conductivity of the formed oxide film is improved,and the reversibility of the transfer reaction of PbSO4/Pb is also improved.The potential of the lead oxidation moved to positive,the over potential for the oxygen evolution reaction on the electrode and the conductivity of the formed oxide film on the electrode are increased,the rate for oxygen evolution reaction at the lead-calcium alloy electrode and the corrosion rate are decreased,and moreover the reversibility for the PbSO4/PbO2 transfer reaction is further improved with the increasing of the concentration of the cerium ion in sulfuric acid solution.