Infrared Spectroscopy was used to study CO adsorption on both the reconstructed (hex) and unreconstructed (1 x 1) surfaces of Pt100 at 300K. On the (1 x 1) surface CO adsorbs on both bridge and on-top sites giving bands at 1864 and 2062/cm, respectively. At a coverage of θ = 0.5 a (√2 x √2)R45° overlayer structure was formed. On the (hex) surface, initially only linear CO was observed at 2083/cm. High resolution spectra (1/cm) show that with increasing exposure a second linear C-O band was observed starting as a high frequency shoulder at 2087/cm. At a coverage of θ = 0.5 this new band was accompanied by a very weak bridge band at 1863/cm. and dominated the spectrum, the intensity of the original CO peak having diminished to zero. Isotopic dilution measurements show that the two linear C-O bands result from CO adsorption initially on the (hex) phase and then on (1 x 1) islands created as the reconstruction was lifted. The results were compared with those for NO adsorption on Pt100.

The Adsorbate-Induced Lifting of the Pt100 Surface Reconstruction - IRAS Investigations. P.Gardner, R.Martin, M.Tüshaus, A.M.Bradshaw: Journal of Electron Spectroscopy and Related Phenomena, 1990, 54-55, 619-28