1 research outputs found
Electron Radiolysis of Ammonium Perchlorate: A Reflectron Time-of-Flight Mass Spectrometric Study
Thin films of ammonium
perchlorate (NH<sub>4</sub>ClO<sub>4</sub>) were exposed to energetic
electrons at 5.5 K to explore the radiolytic
decomposition mechanisms. The effects of radiolysis were monitored
on line and in situ via Fourier transform infrared spectroscopy (FTIR)
in the condensed phase along with electron impact ionization quadrupole
mass spectrometry (EI-QMS) and single-photon photoionization reflectron
time-of-flight mass spectrometry (PI-ReTOF-MS) during the temperature-programmed
desorption (TPD) phase to probe the subliming molecules. Three classes
of molecules were observed: (i) nitrogen bearing species [ammonia
(NH<sub>3</sub>), hydroxylamine (NH<sub>2</sub>OH), molecular nitrogen
(N<sub>2</sub>), nitrogen dioxide (NO<sub>2</sub>)], (ii) chlorine
carrying molecules [chlorine monoxide (ClO), chlorine dioxide (ClO<sub>2</sub>), dichlorine trioxide (Cl<sub>2</sub>O<sub>3</sub>)], and
(iii) molecular oxygen (O<sub>2</sub>). Decay profiles of the reactants
along with the growth profiles of the products as derived from the
infrared data were fit kinetically to obtain a reaction mechanism
with the initial steps involving a proton loss from the ammonium ion
(NH<sub>4</sub><sup>+</sup>) yielding ammonia (NH<sub>3</sub>) and
the decomposition of perchlorate ion (ClO<sub>4</sub><sup>ā</sup>) forming chlorate ion (ClO<sub>3</sub><sup>ā</sup>) plus
atomic oxygen. The latter oxidized ammonia to hydroxylamine and ultimately
to nitrogen dioxide. Molecular oxygen and nitrogen were found to be
formed via recombination of atomic oxygen and multistep radiolysis
of ammonia, respectively