Shock tube measurements of the rate constant for the reaction cyclohexene → ethylene + 1,3-butadiene

The rate constant for the reaction cyclohexene → ethylene + 1,3-butadiene was determined by monitoring the formation of ethylene during the pyrolysis of cyclohexene behind reflected shock waves. Ethylene mole-fraction time-histories were measured using direct laser absorption at 10.532 μm. Experiments were performed between 950–1300 K and 0.8–3.7 atm. Measurements do not indicate any pressure dependence at these conditions. The data are best-fit by an Arrhenius expression k [s−1] = 4.84 × 1014 exp (−31 900 [K]/T) with uncertainties of ±19–36%, depending on the temperature. This appears to be the most accurate determination to date of the rate constant for cyclohexene decomposition.