Voltammetric study of the underpotential deposition of copper on polycrystalline and single crystal palladium surfaces

The underpotential deposition of copper on (100) and (111) palladium single crystals and polycrystalline substrates was investigated voltammetrically. Charge values indicate that the adsorption process leads to the formation of a first monolayer which follows the substrate orientation. On the (100) plane and the polycrystalline substrate a second sub-monolayer was detected. The Kolb correlation between underpotential deposition and work function is discussed taking into account substrate and adsorbate orientation.