Low-Energy Electron-Induced Oligomerization of Condensed Carbon Tetrachloride

Abstract

The low-energy electron-induced chemistry of condensed CCl4 has been investigated with use of post-irradiation temperature-programmed desorption. These experiments were partly motivated by the growing interest in developing facile and economical methods for decomposing CCl4 and other halocarbons which through widespread use in industry have become potent environmental pollutants. The experimental procedure involves low-energy (50 eV) electron irradiation (fluence ≤2 × 1016 electrons cm-2) of nanoscale thin films (5 monolayers) of CCl4 grown at 100 K on a Mo(110) single crystal under ultrahigh vacuum (UHV) conditions. Results of post-irradiation temperature-programmed desorption experiments were used to identify C2Cl4, C2Cl6, C3Cl6, C4Cl6, and C5Clx as low-energy electron-induced reaction products of condensed CCl4. Two longer chain chlorocarbon oligomers with six or more carbons were also detected but not identified. Although low-energy electron-induced oligomerization reactions have been previously repor...