Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (3): 492-499.doi: 10.3866/PKU.WHXB201312301

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Influence of Alloying Element Nd on the Electrochemical Behavior of Pb-Ag Anode in H2SO4 Solution

ZHONG Xiao-Cong1, GUI Jun-Feng1, YU Xiao-Ying1, LIU Fang-Yang1, JIANG Liang-Xing1,2, LAI Yan-Qing1, LI Jie1, LIU Ye-Xiang1   

  1. 1 School of Metallurgy and Environment, Central South University, Changsha 410083, P. R. China;
    2 Powder Metallurgy Research Institute, Central South University, Changsha 410083, P. R. China
  • Received:2013-11-01 Revised:2013-12-30 Published:2014-02-27
  • Contact: JIANG Liang-Xing E-mail:lxjiang@csu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51204208, 51374240), National Science & Technology Pillar Program of China (2012BAA03B04), and Hunan Provincial Natural Science Foundation, China (13JJ1003).

Abstract:

Anodic layers and oxygen evolution reaction (OER) of Pb-Ag and Pb-Ag-Nd anodes were investigated by cyclic voltammetry, linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and environmental scanning electron microscopy (ESEM). Alloying with Nd promoted the formation of Pb/PbOn/PbSO4 (1≤n<2). Nd facilitated the transformation of PbOn and PbSO4 to α-PbO2 and β-PbO2, at potential above 1.2 V vs Hg/Hg2SO4 (saturated K2SO4 solution). ESEM and LSV indicated that the anodic layer formed on the Pb-Ag-Nd anode was thicker and more compact than that formed on the Pb-Ag anode. Consequently, the anodic layer on the Pb-Ag-Nd anode could provide better protection for metallic substrates. EIS indicated that the OER was determined by the formation and adsorption of intermediates. Nd enhanced the OER reactivity, because of a smaller adsorption resistance and larger coverage of intermediates at the anodic layer/electrolyte interface. In summary, alloying with Nd can enhance the corrosion resistance and reduce the energy consumption of Pb-Ag anode due to lower anodic potential.

Key words: Electrowinning, Anodic layer, Passivation, Oxygen evolution, Corrosion resistance

MSC2000: 

  • O646