Water on Pt(111) is generally thought to be non-dissociative. However, by adsorbing a thick ice film (>150 monolayers (ML)), substantial (~0.16 to 1 ML) dissociation of the "buried water" occurs for T > 151K . New temperature-programmed desorption peaks signal the dissociation (after careful isothermal pre-desorption of the overlying ice films). The buried water likely dissociates via the elevated temperatures and/or solvation changes experienced under the ice. Dissociation also creates large work function changes (up to +9V!) due the trapping of ~0.007ML H3O+ at the vacuum-ice interface of the growing ice.
Revised: February 6, 2007 |
Published: January 5, 2007
Citation
Lilach Y., M.J. Iedema, and J.P. Cowin. 2007.Dissociation of water buried under ice on Pt(111).Physical Review Letters 98, no. 1:Art. No. 016105.PNNL-SA-53144.