锌电积工业用新型泡沫铝/Pb-0.6 wt%Ag合金复合阳极电化学性能研究

A New Type Aluminum foam/Pb-0.6 wt%Ag Alloy Composite Anode with Improved Electrochemical Performance for Zinc Electrowinning Industry

摘要:

为改善传统锌电积阳极存在的高析氧过电位和高银含量的缺陷，本文发明了一种新型泡沫铝/Pb-0.6 wt%Ag复合阳极。采用计时电位法，扫描电镜，交流阻抗和塔菲尔测试方法对比研究了在160 g/L H2SO4极化72 h后泡沫铝/Pb-0.6 wt%Ag复合阳极和Pb-0.6 wt%Ag阳极的电化学性能。结果表明：泡沫铝/Pb-0.6 wt%Ag复合阳极的阳极膜比Pb-0.6 wt%Ag阳极的更平整，且抗腐蚀能力更强。此外，泡沫铝/Pb-0.6 wt%Ag复合阳极的稳定阳极电位更小，与其通过计时电位法和交流阻抗获得的高PbO2，低PbO, PbO?PbSO4含量和低Rct值一致。而且还发现泡沫铝/Pb-0.6 wt%Ag复合阳极具有更优异的析氧反应行为。

Abstract:

In order to overcome defects of high over-potential and preparation cost existing in traditional Pb alloy anode, a new type aluminum foam/Pb-0.6wt%Ag alloy composite anode (AF/Pb-0.6 wt%Ag anode) was produced in this paper. And the electrochemical performance of AF/Pb-0.6 wt%Ag anode and traditional Pb-0.6 wt%Ag anode after 72 h galvanostic polarization were investigated comparatively in 160 g/L H2SO4 solution by chronopotentiometry(CP), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Tafel measurements. The results show that the anodic layer of AF/Pb-0.6 wt%Ag anode is more intact than that of Pb-0.6wt%Ag anode, and exhibits better corrosion resistance. Moreover, the AF/Pb-0.6 wt%Ag anode shows a lower stable anodic potential, which is consist with the higher PbO2, lower PbO, PbO?PbSO4 content and Rct value obtained by CP and EIS measurements. It is also revealed that the AF/Pb-0.6 wt%Ag anode possesses better oxygen evolution reaction (OER).