ELECTROCHEMICAL, AUGER-ELECTRON SPECTROSCOPY AND LOW-ENERGY-ELECTRON DIFFRACTION STUDIES OF THE STABILITY OF THE AU(210) ELECTRODE SURFACE IN THE PRESENCE OF ADSORBED PYRIDINE

Electrochemistry, Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) have been employed to study the stability of the Au(210) electrode surface in the presence of adsorbed pyridine. The experiments have been performed in an ultrahigh vacuum (UHV)-electrochemistry apparatus that allows for a fast transfer of the sample between an UHV chamber equipped with LEED and AES equipment and an electrochemical chamber in which electrochemical experiments can be performed. The ''dry emersion'' technique has been employed to emerse the electrode at a controlled potential and to transfer it into the UHV chamber for analysis of its surface composition using AES and its surface structure by LEED. Experiments performed in a weakly adsorbing electrolyte and in 10(-3) M pyridine solution have shown that the Au(210) electrode surface displays a remarkable stability at the metal-solution interface. Its surface structure is apparently unchanged when the electrode charge density varies between -30 mu cm-2 and + 30 muC cm-2, both in a pure weakly adsorbing electrolyte and in the presence of the chemisorbed organic molecule.