Mass Spectrometric Investigation and Computer Modeling of the CH4-O2-O3 Reaction from 480 to 830 K

Article abstract of DOI:10.1021/j100276a039

The reaction of methane with ozonized oxygen was investigated in a molecular beam source reactor, consisting of a heated 1-mm-diameter alumina flow tube equipped with a 0.2-mm nozzle.Typical values for pressure and residence time were 600 mbar and 16 ms, respectively, and the temperature range covered was from 480 to 830 K.The gas mixture expanding from the reactor was transformed into a molecular beam and analyzed by a mass spectrometer.H2O, CO, CH2O, CH3OH, H2O2, CO2, and CH3OOH were found as reaction products.The experimental results could be fairly well modeled by a reaction mechanism consisting of 47 elementary reactions with 21 species.A kinetic sensitivity analysis and investigation of the reaction pathways yields the main mechanistic features of the reaction.The reaction is initiated by the thermal decomposition of ozone.Very important in the reaction are secondary reactions of ozone with methyl radicals and hydrogen atoms.Besides that, radical-radical reactions of methyl and methylperoxy radicals play a dominant role in the course of the reaction.