Effect of adsorption of anions on the kinetics of the copper adatom layer formation at polycrystalline platinum

The formation of copper adatom layers at polycrystalline platinum in sulfate and perchlorate solutions is studied by cyclic voltammetry on a ring-disk electrode. Specific adsorption of anions accelerates the copper underpotential deposition by decreasing the positive potential of the dense part of EDL. Of importance is the anion composition of co-adsorption lattices that form at moderate coverages of platinum by copper. Supermonolayer coatings form under the conditions of strong specific adsorption of anions. In a weakly acid sodium sulfate solution, the surface coverage by copper adatoms reaches 1.7 monolayers.