Unusual CO adsorption sites on vanadium oxide-Pd(111) 'inverse model catalyst' surfaces

The reactive sites of both oxidized and reduced vanadium oxide-Pd(111) surfaces are studied using the adsorption of CO as a test molecule for probing the free Pd sites. The adsorbate and substrate core level x-ray photoelectron spectroscopy (XPS) data indicate that on the reduced, S-V2O3-decorated Pd(111) surfaces, CO occupies the same adsorption site as on the clean Pd(111).