High Temperature Reaction Rate for H + O 2 = OH + O and OH + H 2 = H 2 O + H

Shock heating together with atomic resonance absorption spectrometry (ARAS) was used to record simultaneously H‐ and O‐atom concentration profiles in the post‐shock region behind reflected shocks. The dissociation of N 2 O together with the reaction O + H 2 = OH + H was used as a source of H and OH for the reactions H + O 2 = OH + O and OH + H 2 = H 2 O + H. The test gas mixtures consisted of argon with relative concentrations of a few ppm N 2 O and 100 to 500 ppm H2 and O 2 . The experiments were conducted in the temperature range of 1700 to 2500 K at total densities of 6 · 10 −6 to 1.3 · 10 −5 mol cm −3 . The following rate coefficients were deduced: For temperatures below 2500 K nearly complete agreement with the value for the rate coefficient of reaction R1 as recommended by Baulch [1] was obtained. For reaction R2 a rate coefficient was deduced which is close to the value as given by Gardiner et al. [23].