Low energy water ion deposition and collision-induced dissociation on Pt(111)
- Pacific Northwest National Labs., Richland, WA (United States); and others
A mass selected molecular ion source built to deposit aqueous-like ions (H{sup 3}O{sub +},H{sub +},NH{sup 4}+, and anions) at low energy (2 ev) has been completed. A study of D{sup 2}O ion deposition on clean Pt(111) is reported on, as well as preliminary results for D{sup +3}O{sub +} deposition on ice layers. For D{sup 2}O{sub +}, the ion was deposited on the surface at energies from 3 to 27 eV. It is expected to neutralize by resonant charge transfer near the surface. We found that D{sup 2}O{sub +} dissociates at higher kinetic energy with high probability, but stays intact below a threshold energy of 10 {+-} eV. The molecular sticking probability decreases rapidly with kinetic energy, being 0.14 at 3 eV and 0.04 at 20{sub 2}eV. The dissociation involves oxygen ejection since TPD after deposition shows D{sup 2} but no oxygen desorbing, other than in water. Probably this is simply a type of {open_quotes}spectator{close_quotes} collision, whereby the oxygen, carrying most of the momentum, bounces oblivious to the deuterium`s fate.
- OSTI ID:
- 539071
- Report Number(s):
- CONF-960807-; TRN: 97:004029-0140
- Resource Relation:
- Conference: 212. national meeting of the American Chemical Society (ACS), Orlando, FL (United States), 25-30 Aug 1996; Other Information: PBD: 1996; Related Information: Is Part Of 212th ACS national meeting; PB: 1830 p.
- Country of Publication:
- United States
- Language:
- English
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