Coadsorption of CO with methanol, water and xenon on Pt(111): Band suppression in vibrational spectroscopy

Abstract

The coadsorption of CO with CD 3 OD, D 2 0 and Xe on Pt(111) at 90 K has been studied by means of IR reflection/absorption spectroscopy (IRAS) in the spectral range between 1500 and 2150 cm -1 , where the CO stretch vibrational band usually occurs. Independent of the order of exposure a considerable suppression of the intensity of the CO stretch vibration band near 2100 cm -1 is found for all three gases. Annealing experiments show that CO remains adsorbed and is not removed by the coadsorbed species. As a probable explanation for the effect electronic shielding of the dynamic dipole moment of the CO in the coadsorption system is discussed.