Temperature dependence of the laser-enhanced reaction NO+O3 (001). II. Contributions from reactive and nonreactive channels

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Abstract
The reaction NO+O3(001) was studied over the temperature range 158–437 K. A CO2 TEA laser was used to excite ozone in a rapidly flowing mixture of O3, Ar, and NO. The total decay rate of the laser‐induced chemiluminescent signal showed a strong non‐Arrhenius temperature dependence. This decay rate is the sum of contributions from three processes: the laser‐enhanced luminescent reaction, the laser‐enhanced nonluminescent reaction, and vibrational relaxation of O3(001) by NO. A kinetic model is proposed to determine each of the rate coefficients from the size and shape of the laser‐induced signal. Our analysis shows that the rate coefficient of the laser‐enhanced nonluminescent reaction has an Arrhenius form, with an activation energy that is lowered by approximately 1.6±0.4 kcal/mol. The rate coefficient for relaxation of ozone has a minimum at 225 K, suggesting that attractive forces are important in the nonreactive channel.