网状和片状氧化涂层阳极在电解锌过程中的电化学行为

摘要

The catalytic performance of two oxides coated anodes (OCSs) meshes and one OCA plate was investigated in a zinc electrowinning electrolyte at 38 °C. Their electrochemical behaviors were compared with that of a conventional Pb−0.7%Ag alloy anode. Electrochemical measurements such as cyclic voltammetric, galvanostatic, potentiodynamic, open-circuit potential (OCP) and in situ electrochemical noise measurements were considered. After 2 h of OCP test, the linear polarization shows that the corrosion current density of the Ti/(IrO2−Ta2O5) mesh electrode is the lowest (3.37μA/cm2) among the three OCAs and shows excellent performance. Additionally, after 24 h of galvanostatic polarization at 50 mA/cm2and 38 °C, the Ti/MnO2mesh anode has the highest potential (1.799 V), followed by the Ti/(IrO2−Ta2O5) plate (1.775 V) and Ti/(IrO2−Ta2O5) mesh (1.705 V) anodes. After 24 h of galvanostatic polarization followed by 16 h of decay, the linear polarization method confirms the sequence obtained after 2 h of OCP test, and the Ti/(IrO2−Ta2O5) mesh attains the lowest corrosion current density. The Ti/(IrO2−Ta2O5) mesh anode also shows better performance after 24 h of galvanostatic polarization with the overpotential lower than that of the conventional Pb−Ag anode by about 245 mV.%研究两个网状和一个片状氧化涂层阳极在38°C的电解锌溶液中的催化性能，并与通用的Pd−0.7%Al合金的电化学性能进行对比。采用电化学测试方法进行实验，如循环动电位法、恒电流法、动电位法、开路电位法和原位电化学噪音法。经过2 h的开路电位实验，线性极化结果表明：网状Ti/(IrO2−Ta2O5)电极显示出非常好的性能，其腐蚀电流密度在三个氧化涂层阳极中是最低的(3.37μA/cm2)。此外，在50 mA/cm2和38°C的条件下，经过24 h的恒电流极化试验，网状Ti/MnO2阳极有最高的电位(1.799 V)，紧随其后的是片状Ti/(IrO2−Ta2O5)(1.775 V)和网状Ti/(IrO2−Ta2O5)阳极(1.705 V)。经过24 h的恒电流极化和16 h时的电位衰退实验后，线性极化方法验证了经过2 h的开路电位实验得出的结果，即网状Ti/(IrO2−Ta2O5)阳极有最低的腐蚀电流。网状Ti/(IrO2−Ta2O5)阳极在24 h极化后显示出更好的性能，并与通用的Pb−0.7%Al合金进行相比，过电位低~245 mV。