Oxygen as an Electron Scavenger: Its Role in Electron-Induced
Activation of Coadsorbed Methane Embedded in Amorphous Solid Water
Sujith Ramakrishnan
Roey Sagi
Elishama Sorek
Rabin Rajan J. Methikkalam
Micha Asscher
10.1021/acs.jpcc.8b06388.s001
https://acs.figshare.com/articles/journal_contribution/Oxygen_as_an_Electron_Scavenger_Its_Role_in_Electron-Induced_Activation_of_Coadsorbed_Methane_Embedded_in_Amorphous_Solid_Water/7157165
Low-energy electrons are known to
play a fundamental role in activating
small molecules in interstellar chemistry. Here we illustrate the
electron-induced activation of the inert molecule methane while sandwiched
between two 50 monolayers thick layers of amorphous solid water (ASW)
on ruthenium substrate at 25 K by employing externally supplied low-energy
electrons (5 eV) under ultrahigh vacuum conditions. We demonstrate
how electron transmission through ASW layers under cryogenic conditions
is strongly affected in the presence of cosandwiched oxygen molecules.
We conclude that the resonant nature and direct electron attachment
process leads to a higher degree of conversion in the presence of
embedded oxygen molecules along with methane. Cross sections ranging
from 1 × 10<sup>–18</sup> to 1 × 10<sup>–19</sup> cm<sup>2</sup>/electrons were obtained from the post-irradiation
temperature-programmed desorption spectra.
2018-09-14 00:00:00
molecule methane
presence
cosandwiched oxygen molecules
Coadsorbed Methane
electron-induced activation
cryogenic conditions
Water Low-energy electrons
Cross sections
oxygen molecules
ASW layers
Electron Scavenger
Electron-Induced Activation
electron attachment process
ruthenium substrate
electron transmission
post-irradiation temperature-programmed desorption spectra
50 monolayers
ultrahigh vacuum conditions
25 K