Formation of Hydrogen Atoms in Pyrolysis of 2,2-Dimethylpropane behind Shock Waves

Article abstract of DOI:10.1021/j100242a032

Dilute mixtures (5-20 ppm) of 2,2-dimethylpropane (neopentane) were pyrolyzed behind reflected shock waves at temperatures of 1140-1300 K and total pressures of 2-3 atm.Progress of the reaction was followed by analysis for H atoms using resonance absorption spectroscopy.Appearance of H atoms was a first-order process with respect to time, an Arrhenius equation for the appearance of H atoms, based on 61 experiments, being k_H = 2.65E17exp(-86300/RT) s^-1, where the activation energy is in calories.Taking into account two minor side reactions, the first-order rateconstant for the first step in neopentane pyrolysis, (CH3)4C -> (CH3)3C. + CH3 (1) was found to be k₁=1.7E17exp(-84000/RT) s^-1 with an estimated uncertainty of a factor of 2 in k_H and k₁.