A study was made of the effect of surface defects on ordered epitaxial films which had been grown onto (111)Pt. This involved the monitoring of the adsorption of H2O, diethyl ether, ethanol and their fluorinated analogues. Defects on the stoichiometric surface were produced by Ar ion sputtering, and were characterized by a loss of O; as indicated by ion-scattering spectroscopy. It was found that new adsorption sites were produced where H2O bonded dissociatively, and produced H2 upon heating at temperatures above 400K. The diethyl ether also acquired a new higher-energy binding site at the defective surface. However, perfluorinated ether was not affected by the presence of surface defects. The surface defects could be removed by annealing in O2 or H2O.

K.Takeuchi, S.S.Perry, M.Salmeron, G.A.Somorjai: Surface Science, 1995, 323, 30-8