Electrochemical behavior of Pb-Ag-Nd alloy during pulse current polarization in H_2SO_4 solution  

Pb-Ag-Nd合金在H_2SO_4溶液脉冲电流极化过程中的电化学行为（英文）

作　　者：钟晓聪[1] 于枭影[1] 蒋良兴[1] 李飞 李劼[1] 刘业翔[1] 

机构地区：[1]中南大学冶金与环境学院,长沙410083 [2]河南豫光锌业有限责任公司,济源459000

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第5期1692-1698,共7页中国有色金属学报（英文版）

基　　金：Projects(51204208,51374240)supported by the National Natural Science Foundation of China;Project(2012BAA03B04)supported by the National Science and Technology Pillar Program of China;Project(2014zzts028)supported by the Fundamental Research Funds for the Central Universities of Central South University,China

摘　　要：The anodic layer and oxygen evolution behavior of Pb-Ag-Nd alloy during pulse current polarization and constant current polarization in 160 g/L H2SO4 solution was comparatively investigated by chronopotentiometry, SEM, XRD, EIS and Tafel techniques. The results show that the anodic layer on Pb-Ag-Nd alloy formed through pulse current polarization is more intact and presents fewer micro-holes than that formed through constant current polarization. This could be attributed to the low current density period, which works as a ‘recovery period＇. During this period, the oxygen evolution reaction is less intense, which benefits the recovery of porous anodic layer. Pb-Ag-Nd anode also shows a lower anodic potential during pulse current polarization, which is in accordance with its smaller charge transfer resistance and smaller Tafel slope coefficient at high over-potential region. The lower anodic potential could be ascribed to the higher concentration of Pb O2 in the anodic layer, which promotes the formation of more reactive sites for the oxygen evolution reaction.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。

关 键 词：Pb-based anode pulse current polarization oxygen evolution behavior anodic layer 

分 类 号：TG174[金属学及工艺—金属表面处理]