Kinetics and Products of the Reaction O2(1Σg +) with N2O

Abstract

Abstract Previous studies have suggested that the reaction of O2(1Σg +) + N2O → NO + NO2 may be a significant source of NOx in the atmosphere if the branching ratio of this channel is greater than ~1%. We have measured the overall rate coefficient (k1) for the reaction of O2(1Σg +) with N2O to be k1(295 K) = (1.06±0.14)×10−13 cm3 molecule−1 s−1 at 295 K and k1(T) = (7.48±1.66)×10−14 exp[(87±40)/T] cm3 molecule−1 s−1 as a function of temperature over the range 210–370 K. The yields of NO, NO2 or O3 that are possible reaction products from the title reaction were undetectably small. Also, the net loss of N2O from the title reaction was negligibly small. We report upper limits for the yields for the production of NOx, the production of O3 and the loss of N2O (all at 298 K) to be < 2×10−4, < 1×10−3, and < 3×10−3, respectively. We conclude that the reaction of O2(1Σg +) + N2O is neither a significant source of NOx in the atmosphere nor a significant sink for N2O.