Active centers for CuUPD-OPD in acid sulfate solution on Pt(111) electrodes

A long-term study of Cu UPD and OPD kinetics on the Pt(111) electrode by cy clic voltammetry and potentiostatic current transient techniques has shown that copper oxides CuxO could be considered as the active centers of the ad layer growth and further bulk copper deposition. These species are formed b y a slow surface reaction between the adsorbed oxygen and copper atoms or i ons at potentials E > 0.55 V versus NHE. An enhanced rate of copper cations reduction on the positively charged Pt surface in the vicinity of electron egative CuxO species caused by the local electrostatic effects in the elect ric double layer could be the reason for the accelerating action of these a ctive centers. (C) 2001 Elsevier Science Ltd. All rights reserved.