Bonding and Desorption Mechanismsof CO on Metal Surfaces

Abstract: I have investigated two different systems CO/Fe(100) and CO/Ru(0001), toobtain new information on the binding and desorption processes. The twodifferent systems have served as a model system, one for a static examination,CO on iron, and for the dynamic case, CO on ruthenium. To perform theseinvestigations, several types of techniques have been used such as, X-rayabsorption spectroscopy, X-ray emission spectroscopy, and femtosecond laserinduced desorption techniques such as two-pulse correlation.For the CO/Fe(100) system, we found that the on-top CO “1 phase” canbe described by the Blyholder-Nilsson-Pettersson model. The pre-dissociativephase of CO bound at hollow sites, “3 phase”, can be described in a Dewar-Chatt-Duncanson like picture.For the CO/Ru(0001) system, it was found that all our data could be fitted from an empirical friction heat bath model. Moreover, it turned out, thatthere is a strong frictional coupling to the substrate electrons and phonons.