THE KINETICS OF THE REDUCTION PROCESSES OF PBO FILM IN H2SO4 .6. EFFECTS OF PB-SB ALLOY ELECTRODES

The electrochemical behaviour of PbO film on Pb-Sb electrodes has been studied by the scanning electron microscope (SEM), X-ray diffraction and the electrochemical technique. In the cathodic potential sweep, the easy transformation of tetra-PbO --> 3PbO . PbSO4 . H2O --> PbO . PbSO4 is caused by the many micropores produced in the dissolution of Sb, and the reduction peaks of these three compounds are observed simultaneously on the linear sweep voltammograms. It is found that the rates of their transformation and reduction are controlled by the diffusion of the OH- ion through the anodic film. Also the effects of Sb on the electrochemical behaviour of the tetra-PbO and basic lead sulfate layers are discussed.