Dissociation of water buried under ice on Pt(111).
Water on Pt(111) is generally thought to be nondissociative. However, by adsorbing a thick ice film [>150 monolayers (ML)], substantial (approximately 0.16 to 1 ML) dissociation of the "buried water" occurs for T>151 K. New temperature-programmed desorption peaks signal the dissociation (after careful isothermal predesorption of the overlying ice films). The buried water likely dissociates via the elevated temperatures and/or solvation changes experienced under the ice. Dissociation charges the growing ice film (up to +9 V) due to trapping of approximately 0.007 ML H3O+ at the vacuum-ice interface.
Lilach
Yigal
Y
Pacific Northwest National Laboratory, K8-88, Richland, WA 99354-999, USA. yigalli@yahoo.com
Iedema
Martin J
MJ
Cowin
James P
JP