阳极Pb(Ⅱ)氧化物膜的阴极还原  

The Cathodic Reduction Process of the Anodic Pb(Ⅱ) Oxides Film Formed on Lead

作　　者：柳厚田[1] 梁海河[1] 杨炯[1] 杨春晓[1] 周伟舫[1] 

机构地区：[1]复旦大学化学系,上海200433

出　　处：《化学学报》2002年第3期427-431,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No .2 98730 13)资助项目

摘　　要：采用X射线衍射、光电流谱、线性电位扫描和开路电位衰退等方法研究了Pb电极在 0 .9V(vs.Hg/Hg2 SO4 ) ,4.5mol/LH2 SO4 溶液中生长 2h所得的阳极Pb(Ⅱ )氧化物膜的阴极还原行为 .实验结果表明 :阳极Pb(Ⅱ )氧化物膜主要由PbO微粒和PbO·PbSO4 微粒组成 ,微粒间液膜可供离子输运 ;在LSV负向扫描过程中 ,阳极Pb(Ⅱ )氧化物膜是按溶解 -沉积机理还原的 ,首先PbO微粒表层借助该微粒间的液膜还原为金属铅 ,而待PbO微粒表面层转化的金属铅与PbO·PbSO4 微粒接触后 ,则PbO·PbSO4 就和PbO一起还原 ,而以PbO·PbSO4 的还原进程略快 .The cathodic reduction behavior of the anodic Pb(Ⅱ) oxides film formed on Pb for 2 h in 4.5 mol /L H 2SO 4 solution at 0.9 V (vs.Hg/Hg 2SO 4) has been investigated by X-ray diffraction method (XRD), photocurrent measurements, linear sweep voltammetry (LSV) and open circuit decay curve (OCD). The results show that: (1) The major components of the anodic Pb(Ⅱ) oxides film are PbO particles and PbO·PbSO 4 particles, and the interstitial liquid may serve as the major passage for ion transportation during the reduction of the anodic film. (2) The anodic Pb(Ⅱ) oxides film is reduced via a dissolution-precipitation mechanism during the negative LSV. At first, the surface layer of the PbO particles is reduced to the metal Pb, and then the PbO and PbO·PbSO 4 particles are reduced together, when the metal Pb in the surface layer of the PbO particles meets the PbO·PbSO 4 particles, and the reduction of PbO·PbSO 4 particles is slightly faster than that of the PbO particles.

关 键 词：Pb(Ⅱ)氧化物膜 阴极还原 铅电极 光电流谱法 溶解-沉积机理 正极板栅 铅酸蓄电池 

分 类 号：O646[理学—物理化学]