SPECIFIC ANION ADSORPTION IN THE COURSE OF UPD OF ZN2+ IONS ON PLATINUM

The specific anion adsorption accompanying the upd of Zn2+ ions on pla tinum electrodes has been studied by the radiotracer S-35 labelled sul phate species and Cl-36 labelled Cl(-)ions. It has been found that sul phate ions adsorb readily on the top of technique using Zn adatoms whi le the adsorption strength of Cl(-)ions on the Zn adlayer is significa ntly lower than that of HSO4- (SO42-) ions. Indirect radiotracer evide nce obtained from competitive adsorption studies is presented concerni ng the relatively high adsorbability of H2PO4- ions. It follows from t he experimental results obtained that the calculation of the mass and charge balance (involving the determination of the so-called electroso rption valence) requires the knowledge of the extent of the anion adso rption on the adatom layer. (C) 1997 Elsevier Science S.A.