RING-DISK ELECTRODE STUDIES OF SOLUBLE INTERMEDIATES FORMED DURING THE POLARIZATION OF PB IN H2SO4

The use of a rotating ring-disk electrode to detect soluble Pb(IV) and Pb(II) species released into H-2SO4 has made it possible to give complementary interpretations for the processes occurring during the anodization and successive reduction of Pb electrodes. It has been shown that soluble Pb(IV) species act as intermediates during the formation of tetravalent oxides of Pb, and that the generation of tetravalent products is always preceded by the formation of divalent products even at high positive potentials. During the reduction of PbO2 soluble Pb(IV), and also Pb(II), species are released. Part of the tetravalent products formed at Pb are reduced only at high negative potentials.