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Coverage-dependent desorption kinetics of water on a well-ordered alumina thin film surface.

Authors :
Koshida, H.
Wilde, M.
Fukutani, K.
Source :
Journal of Chemical Physics. 1/21/2024, Vol. 160 Issue 3, p1-9. 9p.
Publication Year :
2024

Abstract

We have developed an experimental and analytical setup for thermal desorption spectroscopy of solid water films on surfaces. We obtain the coverage-dependent desorption kinetics of water molecules from a well-defined ultra-thin alumina/NiAl(110) surface in the coverage range of 0–2 monolayers. We use a novel deconvolution technique to eliminate the pumping delay of water vapor in the vacuum system, which has previously hindered the accurate estimation of desorption kinetic parameters, such as activation energy and pre-exponential factor. The coverage-dependent Arrhenius analysis reveals that the desorption activation energy decreases with increasing coverage in the sub-monolayer range, indicating that the water–water interaction is not attractive. We also find that the pre-exponential factor for the second layer is higher than that for the sub-monolayer. We explain this difference in terms of transition state theory and propose that entropic effects play a significant role in water desorption kinetics. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219606
Volume :
160
Issue :
3
Database :
Academic Search Index
Journal :
Journal of Chemical Physics
Publication Type :
Academic Journal
Accession number :
174910629
Full Text :
https://doi.org/10.1063/5.0183443