Thermal rate constants of the O₂+N→NO+O reaction based on the ²A′ and ⁴A′ potential-energy surfaces

A detailed quasiclassical trajectory study of the O₂+N→NO+O reaction is performed based on ab initio potential-energy surfaces of the ²A′ and ⁴A′ states. The study is aimed at generating a database of thermally averaged and O₂ state-specific rate constants needed for accurate simulations of NO kinetics in high-temperature flow processes. The rate constants obtained show good agreement with the available experimental data and with other quasiclassical trajectory calculations. It is found that the reactant internal energy of the O₂+N→NO+O reaction is less effective in enhancing the rate than in the N₂+O→NO+N reaction. An analysis of the product vibrational energy shows that NO formed by the O₂+N→NO+O reaction has a non-Boltzmann distribution. It is also found that the most populated NO vibrational level is determined by the reactant vibrational energy, while the terminal slope of the NO vibrational distribution is a strong function of the reactant translational temperature.