Rate Constant of the Reaction HO + CO in the Presence of N2 and O2

The kinetics of the reaction HO + CO was studied in the presence and in the absence of O2 using VUV flash photolysis of H2O and kinetic absorption spectroscopy of HO. In the absence of O2, the value of the rate constant was found to vary from 1.4 · 10−13 cm3 s−1 at low total pressures to (2.30 ± 0.16) · 10−13 cm3 s−1 at atmospheric pressure of N2. In the presence of traces of O2, a complex reaction mechanism is necessary to explain the HO decays. With recent rate data, the mechanism allows us to reinterpret the experimental data of Biermann et al. [9] which were significantly influenced by secondary reactions thus simulating the previously reported O2‐effect.