ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We have studied electron stimulated desorption of positive ions from ∼15 monolayer (ML) film of pure solid CO2 adsorbed on polycrystalline Pt surface at ∼40 K using incident electrons in the energy range 1–31 eV. The positive ions O+, C+, CO+, CO2+, and O2+ were observed and their threshold energies are discussed. Hydrogenation of the CO2 film was found to reduce the O2+ production but the threshold remained the same as for the pure CO2 matrix. After hydrogenation of the CO2 matrix additional ions—H+, H3O+, HCO+, and H2CO+—are observed. The formation of formaldehyde cations (with a threshold energy of 17±1.5 eV) in the hydrogenated CO2 matrix has been observed for the first time and is a product of electron stimulated ion—molecule reactions, possibly via a process analogue to the so-called photosynthesis. These results could be relevant to a better understanding of the atmosphere of Mars. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.478987
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