Specific adsorption of anions in the course of underpotential and bulk depositions and alloy formation of cadmium on a smooth gold support in acid medium

The specific adsorption of Cl-36-labelled Cl- ions and S-35-labelled HSO4- ions was studied in 1 mol dm(-3) HClO4 supporting electrolyte in the presen ce of Cd2+ ions at a gold support over a wide potential range corresponding to electrodeposition, alloy formation, underpotential deposition of Cd spe cies and existence of an adatom-fi ee surface. The distinct sections in the potential dependence of the adsorption of anions together with the potenti al versus time curves obtained under open circuit conditions reflect the ch anges in the state of the electrode surface, the dissolution of the bulk Cd phase and the slow elimination of Cd species from the Cd/Au alloy.