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采用计时电位、SEM、XRD、EIS和Tafel等方法对比研究Pb-Ag-Nd合金在160 g/L H2SO4溶液中的脉冲电流极化和恒电流极化过程中的氧化膜和析氧行为。研究结果表明:脉冲电流极化的Pb-Ag-Nd合金表面的氧化膜孔洞更少,膜层更致密。这是由于在脉冲电流极化过程中的低电流阶段析氧反应更缓和,有利于多孔氧化膜的修复,因此低电流阶段可作为氧化膜的“修复期”。Pb-Ag-Nd阳极在脉冲电流极化过程中表现出更低的阳极电位,这与脉冲电流极化过程中阳极更小的传荷阻抗和高过电位区间更小的Tafel斜率相对应。更低的阳极电位可能与其氧化膜中更高的PbO2含量有关,因为PbO2可以促进析氧反应活性位点的生成。
The time-dependent potentials, SEM, XRD, EIS and Tafel methods were used to study the oxide film and oxygen evolution behavior of Pb-Ag-Nd alloy in pulse current polarization and galvanostatic polarization in 160 g / L H2SO4 solution. The results show that the surface of Pb-Ag-Nd alloy with pulsed current polarization has fewer holes and more dense film. This is due to the more gradual oxygen evolution reaction during the low-current phase of pulsed current polarization, which is conducive to the repair of porous oxide film. Therefore, the low current phase can serve as the “repair period” of the oxide film. The Pb-Ag-Nd anode exhibits a lower anode potential during pulsed current polarization, which corresponds to the smaller charge transfer impedance of the anode during pulsed current polarization and the smaller Tafel slope above the overpotential. The lower anodic potential may be related to the higher PbO 2 content in its oxide film because PbO 2 can promote the formation of reactive sites for oxygen evolution reactions.