The reaction of ammonia with nitrogen dioxide in a flow reactor: Implications for the NH2 + NO2 reaction

The NH₃/NO₂ system has been investigated experimentally in an isothermal flow reactor in the temperature range 850-1350 X. The experimental data were interpreted in terms of a detailed reaction mechanism. The flow reactor results, supported by a theoretical analysis of the NH₂-NO₂ complex, suggest that the NH₂ + NO₂ reaction has two major product channels, both proceeding without activation barriers:(R20) NH2 reversible arrow N₂O + H₂O(R20) NH₂ reversible arrow H₂NO + NOOur findings indicate that the N₂O + H₂O channel is dominant at low temperatures while H₂NO + NO dominates at high temperatures. The rate constant for reaction (R21) is estimated to be 3.5 . 10(12) cm(3)/mol-s in the temperature range studied with an uncertainty of a factor of 3.