AVS 47th International Symposium
    Surface Science Thursday Sessions
       Session SS2+VT-ThM

Paper SS2+VT-ThM1
Alkali Metal and H@sub 2@O Co-adsorption and Reaction on Graphite(0001)

Thursday, October 5, 2000, 8:20 am, Room 209

Session: Adsorption and Desorption Phenomena II
Presenter: M.A. Gleeson, Chalmers University of Technology and Göteborg University, Sweden
Authors: M.A. Gleeson, Chalmers University of Technology and Göteborg University, Sweden
D.V. Chakarov, Chalmers University of Technology and Göteborg University, Sweden
B. Kasemo, Chalmers University of Technology and Göteborg University, Sweden
Correspondent: Click to Email
A comparative study of alkali metal (Na, K, Cs) adsorption, co-adsorption and reaction with H@sub 2@O on the basal plane of graphite has been performed. Water molecules are stabilised by interaction with alkali atoms, and undergo coverage and temperature dependent reactions. The surface solvation number is similar for all three alkali metals at low coverages (3 to 4 H@sub 2@O molecules per alkali atom). The critical alkali coverage for reactive co-adsorption at 98 K ranges between 0.1 to 0.25 ML. Reaction between H@sub 2@O and the alkali metals leads to the formation of hydroxide, hydride and oxide species on the surface. Additional peaks appear in the water desorption spectra due to alkali-stabilised H@sub 2@O and hydroxide decomposition. Decomposition of alkali oxides at high temperature can result in oxidation of the graphite and subsequent CO@sub 2@ evolution. Similarities and differences between the alkali metals are discussed.