F. Solymosi, A. Berkó, T. Tarnóczi
Dec 1, 1987
Citations
0
Influential Citations
16
Citations
Journal
Journal of Chemical Physics
Abstract
The interaction of methanol with potassium‐dosed (up to monolayer) Rh(111) surface has been studied by means of thermal desorption, ultraviolet photoemission (He ii) spectroscopy and work function measurements. Preadsorbed potassium significantly influenced the adsorption, desorption, and stability of CH3OH on this Rh surface, but the pathway of the dissociation of CH3OH and its surface decomposition were not altered. An increase (6–10 kJ/mol) in the binding energy of chemisorbed CH3OH was found even in the low potassium coverage range, θK=0.05–0.26. At higher potassium coverages (θK=0.36, monolayer), where K exhibits mainly metallic character, the relative amount of irreversibly adsorbed methanol was greatly increased. In this case methoxy species was detected by He ii photoemission studies: its complete decomposition occurred at around 492–505 K. The stabilization of the methoxy species was reflected in the high temperature for the evolution of H2(TP=515 K), too. In the interpretation of the data a dire...