The vibrational spectrum and adsorption site of CO on the Ru(001) surface

Abstract
Vibrational spectra and LEED structures of CO on the Ru(001) surface were measured as a function of coverage at 100 K. The LEED patterns indicate that CO occupies a variety of asymmetric sites at high coverage, while the vibrational spectra show a single Ru–C stretching frequency (445 cm−1) and a single C–O stretching frequency (1980–2080 cm−1) at all coverages. This shows that on this surface the CO adsorption site at high coverages is determined by interadsorbate interactions, and that the carbon–oxygen stretching frequency is not site sensitive within the resolution of electron scattering measurements.