The electrodissolution of base palladium in relation to the oxygen electroadsorption and electrodesorption in sulphuric acid solution

The electrodissolution of palladium electrode immersed in 1 M H 2 SO 4 under both repetitive triangular potential sweeps and combined potential perturbation functions has been investigated by using the rotating ring—disc electrode technique. The contribution of palladium electrodissolution in the voltammogram changes in going from the first potential scan to the following ones. This contribution also depends on the characteristics of the potential perturbation programme applied to the electrode. Different potential ranges associated with the formation of soluble palladium(II) are distinguished, which correlate with those corresponding to electrochemical reactions already established. The results are explained through a competitive reaction pathway involving the formation of Pd(OH) and Pd(OH) + intermediate species. The influence of ageing effects and anion adsorption on the formation of soluble palladium(II) is also discussed.