Ab initio chemical kinetics of methylcyclohexyl radical with O2

Abstract

Methylcyclohexane is one of the important components of transportation alternative fuels, and its reaction kinetics of low temperature combustion are crucial for the performance of advanced combustion engines, especially for autoignition. In the present work, we study 3-methylcyclohexyl radical (3MCHyl) as a model compound to clarify the kinetics of methylcyclohexyl radical with O2 and the subsequent isomerization and dissociation of cis 3-methylcyclohexylperoxyl (cis-3MCHylOO). Combined the electronic structure calculations with Rice–Ramsperger–Kassel–Marcus/Master Equation (RRKM/ME) method, we determine previously missing kinetics data in a wide temperature and pressure range. The similarities and difference of kinetics between various methylcyclohexyl conformation with O2 are clarified, which is helpful to better understand the formation mechanism of highly oxygenated molecules (HOM) and combustion pollutants. The accurate calculated kinetics data in the present work are crucial and valuable for the prediction of ignition properties of alternative fuels.