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Published on: March 27, 2019
D(2) desorption kinetics on amorphous solid water: from compact to porous ice films
Jean-Hugues Fillion1, Lionel Amiaud, Emanuele Congiu
1LERMA-LAMAp, UMR CNRS 8112, Université Cergy-Pontoise et Observatoire de Paris, 5 Mail Gay-Lussac, F-95000, Cergy-Pontoise, France. jean-hugues.fillion@upmc.fr
Physical Chemistry Chemical Physics : PCCP
|May 22, 2009
Summary
Deuterium (D2) binding energy on amorphous solid water (ASW) ice increases with surface porosity. Even a few monolayers of porous ice significantly alter D2 adsorption, driven by surface disorder.
Area of Science:
- Surface Science
- Astrochemistry
- Physical Chemistry
Background:
- Amorphous solid water (ASW) is a relevant medium in astrochemistry.
- Understanding molecule-ice interactions is crucial for astrobiology and planetary science.
- Deuterium (D2) adsorption on ASW provides insights into surface properties.
Purpose of the Study:
- Investigate the desorption kinetics of D2 from ASW films.
- Determine how film structure (porosity) affects D2 binding energy.
- Elucidate the role of surface morphology in molecular adsorption on ice.
Main Methods:
- Temperature-programmed desorption (TPD) technique was employed.
- ASW films with varying porosity (compact and porous) were grown on copper.
- TPD spectra were simulated to obtain D2 binding-energy distributions.
Main Results:
- Porous ASW films exhibit D2 binding energies extending to higher values compared to compact films.
- Increasing porosity shifts the D2 thermal desorption peak to higher temperatures.
- Even a few monolayers of porous ASW significantly influence D2 adsorption properties.
Conclusions:
- The binding energy of D2 on ASW is strongly influenced by topological and morphological disorder.
- Porous ice structures create more energetic binding sites for D2.
- Surface disorder, not just ice thickness, governs D2 adsorption on ASW.
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