Adsorption of carbon monoxide on the gold(332) surface

Abstract

The adsorption of carbon monoxide on the Au(332) surface has been investigated by low-energy electron diffraction, surface-potential measurements, temperature-programmed desorption and infrared spectroscopy. The surface potential was found to increase monotonically with coverage, while the isosteric enthalpy of adsorption derived from isobaric desorptions was found to be 55 kJ mol^–1 at low coverages, falling progressively to 20 kJ mol^–1 at saturation. No ordered overlayer structures were obtained. Infrared studies showed a band appearing above 2120 cm^–1 initially and moving smoothly to lower wavenumber with increasing coverage. Although some structure was evident in the band envelope, distinct components could not be resolved in single-isotope spectra. Spectra from C¹⁶O–C¹⁸O mixtures, however, indicated the presence of four separate components.