Effects of antimony on the formation process of 3PbO center dot PbSO4 center dot H2O on Pb and Pb-Sb electrodes

The effects of antimony on the formation process of 3PbO . PbSO4.H2O (3BS) on Pb and Pb-Sb electrodes have been studied by linear sweep voltammetry (L SV), etc. Experimental results indicate that the formation of 3BS depends o n the behavior of the PbSO4 passivation layer. When the anodic film is pass ivated seriously, the diffusion of ions through the PbSO4 layer is the rate -determining step in the formation of 3BS. As the passivation layer is part ly re-activated, the rate of 3BS formation is controlled by solid state nuc leation and growth under the diffusion limitation. In the positive potentia l sweep, the presence of Sb in the alloy promotes the formation of 3BS, and the amount of 3BS formed becomes greater with decreasing H2SO4 concentrati on. (C) 2000 Published by Elsevier Science B.V.