Kinetics of chemi-ionization in atomic O + N mixtures

Abstract

The kinetics of chemi-ionization in atomic O + N mixtures have been investigated in a discharge-flow system using e.p.r. and electron cyclotron resonance (e.c.r.) detection. The reaction is catalysed by hydrocarbons, and ethylene was used as a model catalyst. A mechanism was developed to explain the observed electron production rates and to model by computer the electron concentration against time profiles. The results are consistent with N₂(A³∑⁺_u)+NO (a⁴II)→ N₂+NO⁺+e^– as the dominant chemi-ionization process in which one of the metastable species is produced by an ethylene-catalysed reaction. The electron concentration decay behaviour was explained by the participation of two electron-attaching reaction intermediates which are produced by reaction of O and N with C₂H₄ on the walls of the reactor.