Submonolayer Pt-0 coatings are synthesized by the displacement of copper adatoms (Cu-ad) on polycrystalline (pc) Au in PtCl42- solutions (supporting electrolyte 0.5 M H2SO4). Cyclic voltammograms (CVA) measured on Pt-0 Au demonstrate that for initial surface coverages theta(Cu) < 0.5, the Pt-0 adatoms that have displaced Cuad are mainly deposited in the first layer. At large surface coverages, the agglomeration of Pt-0 and its partial deposition into the second layer take place; similar to 30% of Au surface remains free. SEM, XPS and Auger-spectroscopic data confirm the absence of multilayer Pt-0 agglomerates. The specific rates of CH3OH electrooxidation (per cm(2) of Pt) on Pt-0 Au turn out to be much lower than on pc Pt-0. This is explained by the fact that dehydrogenation of CH3OH requires the presence of areas formed by a large number of platinum atoms (> 3). For HCOOH, the strong increase (more than by one order of magnitude) in both non-steady-state and steady-state specific electrooxidation currents is observed. It is assumed that new active sites are formed for the current-determining reaction that proceeds through the one-site adsorption of HCOOH molecules. (C) 2014 Elsevier Ltd. All rights reserved.