The interaction of methanol with a titanium(001) surface investigated using photon stimulated desorption and UV photoemission spectroscopy

Synchrotron radiation at NBS SURF II has been utilized to study the interaction of methanol with a stepped Ti (001) single crystal surface at about 90 and 300 K. The techniques of photon stimulated desorption (PSD) and UV photoemission spectroscopy (UPS) were employed. Exposure of the clean surface at 300 K to methanol initially results in dissociative adsorption with features indicative of C, O, and H appearing in UPS. At higher exposures, features that have been identified as being characteristic of a methoxy species appear. At 90 K, this species is found to be present even at low exposures, and there is little, if any, further dissociation. Multilayers of methanol are then formed at higher exposures. PSD of ions from the condensed methanol multilayers was observed using photon energies from 15 to 75 eV with a maximum yield at about 25 eV. Using electron stimulated desorption and time of flight mass spectroscopy, the ions were identified as H+. Partial photoionization yields as a function of photon energy were measured for comparison with the PSD yield spectrum. No PSD was detected from the methoxy species.