Study of hydroxyl formation on Pt(111) surface by EELS and low temperature reaction quenching

Abstract The thermal evolution of the hydroxyl species formed from the reaction of adsorbed oxygen and water on a Pt(111) surface have been studied using high resolution electron energy loss spectroscopy (HREELS) in combination with low temperature reaction quenching. At low oxygen coverages (θ ≪ 0.25), it was found that an exposure of 0.3 L of H 2 O resulted in the spontaneous formation of hydroxyl species. At high H 2 O exposures, couped with careful thermal annealling, it has been possible to observe the intermediate states in the evolution of the hydroxyl species. The appearance of a strong 660 cm -1 band indicates strong hydrogen bonding of the H 2 O molecule to the adsorbed oxygen. Further heating leads to the rupture of the water molecule bond and the formation of the hydroxyl species.