Electrolyte electroreflectance study of carbon monoxide adsorption on polycrystalline silver and gold electrodes

We have carried out an electrolyte electroreflectance (EER) study of the adsorption of CO on polycrystalline Ag and Au electrodes. EER proved to be a very sensitive tool for detecting the presence of chemisorbed CO on the surface of the Ag electrode, clearly distinguishing between strong adsorption (chemisorption) and weak adsorption (physisorption). In the case of Au, onto which CO chemisorbs in both alkaline and acid media, EER also detects the presence of this chemisorbed CO. However, while in alkaline medium CO adsorption provokes major changes in the EER spectrum of Au, in acid medium only tumor changes are observed, since the CO coverage is 10 times lower than that in the former case. An analysis of the EER spectra of CO-covered An provided valuable information regarding the surface electronic levels involved in the formation of the chemisorption bond. (C) 2003 Elsevier Ltd. All rights reserved.