Document Type
Article
Date
11-21-2008
Keywords
TBD
Language
English
Disciplines
Physics
Description/Abstract
The study of the formation of molecular hydrogen on low temperature surfaces is of interest both because it allows to explore elementary steps in the heterogeneous catalysis of a simple molecule and because of the applications in astrochemistry. Here we report results of experiments of molecular hydrogen formation on amorphous silicate surfaces using temperature-programmed desorption (TPD). In these experiments beams of H and D atoms are irradiated on the surface of an amorphous silicate sample. The desorption rate of HD molecules is monitored using a mass spectrometer during a subsequent TPD run. The results are analyzed using rate equations and the activation energies of the processes leading to molecular hydrogen formation are obtained from the TPD data. We show that a model based on a single isotope provides the correct results for the activation energies for diffusion and desorption of H atoms. These results can thus be used to evaluate the formation rate of H_2 on dust grains under the actual conditions present in interstellar clouds.
Recommended Citation
Vidali, Gianfranco; Li, Ling; Roser, J.; and Congiu, E., "Molecular Hydrogen Formation on Low Temperature Surfaces in Temperature Programmed Desorption Experiments" (2008). Physics - All Scholarship. 505.
https://surface.syr.edu/phy/505
Source
Harvested from Arxiv.org
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.
Additional Information
30 pages, 1 table, 6 figures. Published version More information at http://arxiv.org/abs/0708.1647
Authors listed are from Syracuse University. For additional authors, click "Download."