MnO4-和银含量对铅银合金阳极电位衰减期电化学行为的影响

摘要

The effect of MnO4−and silver content on electrochemical behaviour of five commercial Pb−Ag alloy anodes was studied in acid zinc sulphate electrolyte with and without MnO4− ions at 38 °C during potential decay periods. When the anodes were immersed into acid zinc sulphate electrolyte without MnO4−ions, the Pb−0.72%Ag anode entered complete passivation state in the shortest time among the five anodes, followed by anodes Pb−0.67%Ag, Pb−0.60%Ag, Pb−0.58%Ag and Pb−0.29%Ag−0.1%Ca by measurement of open circuit potential. During immersion of the anodes, MnO4−ions accelerated the passivation and increased the corrosion current density of the anodes. After immersion in zinc electrolyte with MnO , the anode Pb−0.72%Ag had the best−4 corrosion resistance, followed by anodes Pb−0.67%Ag, Pb−0.60%Ag, then the close anodes Pb−0.58%Ag and Pb−0.29%Ag−0.1%Ca by the electrochemical impedance spectroscopy (EIS) analysis.%　　研究在电位衰变期间在酸性硫酸锌电解液中，MnO4−和银的含量对5个通用铅银合金阳极电化学行为的影响。当阳极浸入不含MnO 的酸性硫酸锌电解液中时，通过开路电位测定，发现Pb−0.72%Ag进入完全钝化状态所用的时间最短，紧接着的是阳极Pb−0.67%Ag、Pb−0.60%Ag、Pb−0.58%Ag和Pb−0.29%Ag−0.1%Ca。在5 h 的浸入期间，MnO4−离子能加速钝化和增加阳极的腐蚀电流密度。通过交流阻抗法测定，发现在含有MnO4−的电解液中，阳极Pb−0.72%Ag具有最好的耐蚀性，紧接着的是阳极Pb−0.67%Ag、Pb−0.60%Ag，然后是阳极Pb−0.58%Ag和Pb−0.29%Ag−0.1%Ca。−4