ELECTRODE/ELECTROLYTE INTERPHASE STUDY USING POLARIZATION MODULATED FTIR REFLECTION ABSORPTION SPECTROSCOPY.

Abstract

The authors present the results of studies of adsorption and oxidation of CO on Pt and adsorption of CN** minus on Ag, Au, Cu and Pt electrodes. Adsorption of CN** minus was studied on Ag, Au, Cu and Pt electrodes in 1N K//2SO//4. The vibrational spectra of the surface cyanide species as well as of the metal-cyanide complexes produced by the anodic reaction between the electrode metal and cyanide ions in solution were observed. Assignment of the species involved was done on the basis of the observed vibrational spectra. From the IR spectroscopic data, the authors conclude that for CO adsorbed at 0. 4 V oxidation takes place mostly at the edges of CO islands. The oxidation, which is completed before the oxygen region, should proceed via a surface reaction between the adsorbed CO and a water molecule adsorbed adjacent to the CO site. On the other hand, oxidation proceeds uniformly in the CO layer for CO adsorbed at 0. 05 V thus changing the intermolecular coupling as the surface coverage of CO decreases.