A kinetic and AFM study of the Electrodeposition of Palladium Nanoclusters onto Highly Oriented Pyrolitic Graphite (HOPG).

In the present work we have carried out a kinetic and morphological study of the palladium electrodeposition onto highly oriented pyrolitic graphite electrode from an aqueous solution [0.001 M PdCl2 + 1 M NH4Cl (pH 7)]. From the potentiostatic study were calculated the diffusion coefficient (3.2 × 10?6 cm2 s?1), the number of active nucleation sites (N 0), the nucleation rate (A) and the rate constant of the proton reduction process (k PR). A, N 0 and k PR values were potential dependent and they increased with an augment in the applied overpotential. At higher overpotential, it is possible to induce the formation of small Pd clusters with 5 nm in height and an average size of 20?30 nm in diameter.