Structure of the Water Layer on Platinum Electrodes

The interface structure of Pt electrodes in aqueous solution – a key model system in electrochemistry – has attracted great current interest. Recent electrochemical measurements and theoretical studies suggest a crucial role of adsorbed water layers within the electrochemical double layer, but propose different models. The true interface structure is currently not resolved due to lack of experimental data on the microscopic arrangement of the interfacial water. We here propose to obtain such data by in situ high energy surface X-ray diffraction (HESXRD) studies, which allow to reliably determine the small scattering contribution of water adlayers. We will employ this method for systematic clarification of the influence of electrode potential and chemisorbed H and OH layers on the water structure near Pt(111) and Pt(100) electrodes.