A study of the adsorption of formic acid and related molecules onto evaporated copper films, both clean and oxide-covered, by infrared ellipsometric spectroscopy

Species formed on evaporated copper surfaces, both clean and oxide-covered, were examined using ir ellipsometric spectroscopy (IRES). Spectra were obtained for CO adsorbed on both bare and oxide-covered copper, the spectra being in accord with published data. No spectra were observed for formic acid adsorption unless free oxygen was present, in which case a spectrum characteristic of a carbonate species was found. Supporting data were obtained to show that the carbonate species was formed by reaction of formic acid and oxygen on the oxide-covered surface. These data illustrate some of the unique advantages of IRES for studying molecular processes on surfaces.