Effects of H2SO4 concentrations on reduction processes of PbO layer

✍ Scribed by Yonglang Guo; Zhengli Wei; Shounan Hua

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 509 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00275-7

✦ Synopsis

The reduction process of tetra-PbO in different HzS04 solutions has been studied by linear sweep voltammetry, potential step and scanning electron microscope (SEM) techniques. As the HzS04 concentration decreases, more tetra-PbO is formed on a lead electrode and the PbSO4 crystals and the microvoid in the anodic film enlarge. This helps the mass transfer of the H + and SO: -ions and the transformation of tetra-PbO into basic lead sulfates and PbS04. The reduction mechanism of tetra-PbO changes from two-into three-dimensional progressive nucleation and growth of metallic lead with the decrease of the HzS04 concentration. When PbS04 begins to be reduced, tetra-PbO is transformed into PbS04, which is then reduced.