This project is in the general field of analytical and surface chemistry and in the subfields of electrochemical catalysis and spectroscopy. Fourier transform infrared and surface-enhanced Raman vibrational spectroscopies will be used as in situ probes of interfacial electrochemical reactions on noble and transition metal electrodes, especially organic oxidations, with the objective of discerning interfacial composition and molecular transformations underlying the observed electrochemical kinetic behavior. Both aqueous and nonaqueous electrolytes will be employed. Surface crystallographic effects upon adsorbate structure and electrocatalytic reaction pathways will be determined. Real-time methods will be employed to obtain infrared spectra during the voltammetric evolution of irreversible electrode processes. The utility of surface-enhanced Raman spectroscopy as a probe of adsorption at related metal-gas interfaces will also be investigated. Fourier transform infrared and surface-enhanced Raman vibrational spectroscopies, utilized in a complementary way, enable characterization of interfacial electrochemical systems at a molecular level under actual reaction conditions. The results of these studies will yield a more detailed understanding of the mechanisms of electrocatalytic reactions and will provide a basis for the development of improved catalysts for technological processes.