The electrochemical reduction of oxygen on electrodeposited palladium coatings was studied in acid and alkaline media employing the rotating disc electrode (RDE) method. Gold was used as an electrode substrate and Pd was deposited at a constant potential varying the deposition time. Cyclic voltammetry and CO stripping experiments were used for surface characterisation of Pd coatings. The surface morphology of the as-prepared electrodes was examined by atomic force microscopy (AFM). The AFM images revealed the formation of Pd islands on the substrate surface. It was found that in alkaline solution the palladised electrodes show high specific activity for oxygen reduction and it does not depend on deposition time. In acid solution the dependence on the deposition time was in evidence and the specific activity surpassed that of bulk palladium. The oxygen reduction reaction (ORR) on electrodeposited Pd proceeds mainly via a four-electron pathway in both solutions and the reduction mechanism is similar to that on bulk Pd. (C) 2012 Elsevier B.V. All rights reserved.