The Decomposition of Methane by Low-Energy Electrons

The decomposition of methane by a beam of electrons having energies between 15 and 100 ev has been studied using methane pressures between 10−2and 10−3 mm of mercury. The products were frozen out on a surface cooled to about −220 °C and situated approximately 5 millimeters from the electron beam.Ethane, ethylene, and acetylene were found to be the main products along with smaller amounts of saturated and unsaturated higher hydrocarbons. The results provide some evidence that under these experimental conditions ions do not play a major part in the decomposition and a free radical mechanism has been proposed to explain the formation of the main products.