Temperature dependent rate constant for the reaction of H‐atoms with carbonyl sulfide

Abstract

AbstractThe kinetics of the reaction of H‐atom with carbonyl sulfide (OCS) has been investigated at nearly 2 Torr total pressure of helium over a wide temperature range, T = 255–960 K, using a low‐pressure discharge flow reactor combined with an electron impact ionization quadrupole mass spectrometer. The rate constant of the reaction H + OCS → SH + CO (1) was determined under pseudo‐first order conditions, monitoring the kinetics of H‐atom consumption in excess of OCS, k1 = 6.6 × 10−13 × (T/298)3 × exp(−1150/T) cm3 molecule−1 s−1 (with estimated total uncertainty on k1 of 15% at all temperatures). Current measurements of k1 at intermediate temperatures (520–960 K) appear to reconcile previous high and low temperature data and allow the above expression for k1 to be recommended for use in the extended temperature range between 255 and 1830 K with a conservative uncertainty of 20%.