Studies of reactions of importance in the stratosphere. I. Reaction of nitric oxide with ozone

The rate constant for the reaction NO+O3→NO2+O2 has been measured by the fast flow method over the temperature range 203–361 K. Loss of ozone in a large excess of nitric oxide was detected by molecular beam sampling into the electron impact ion source of a quadrupole mass spectrometer. The resulting Arrhenius expression is k=2.34±0.23×10−12 exp(−1450±50/T) cm3 molecule−1 s−1 which predicts k298=1.80×10−14 cm3 molecule−1 s in excellent agreement with previous determinations. Our results suggest a slight curvature in the Arrhenius plot, the activation energy increasing with increasing temperature.