Thermochemical and Kinetic Investigation of Pentanol Oxidation Initiated by Hydrogen, Methyl, Hydroxyl, and Hydroperoxyl Radicals

<i>n</i>-Pentanol is acknowledged as a prospective alternative and a supplement to traditional fossil fuels. H-abstraction reaction assumes a pivotal role in initiating the chain reaction during <i>n</i>-pentanol combustion. To investigate the oxidation characteristics of <i>n</i>-pentanol, the composite quantum chemical methods CBS-QB3 and G4 are employed to obtain thermochemical and kinetic parameters in the H-abstraction reaction of <i>n</i>-pentanol. The calculated isobaric heat capacity provides accurate predictions of the experimental results. Branching ratios underscore that H-abstraction at the C_α site serves as the primary channel between <i>n</i>-pentanol and Ḣ/ĊH₃/ȮH₂. For the reaction between <i>n</i>-pentanol and ȮH, the C_β site emerges as the most favorable channel due to the significant variational effect. The overall rate coefficient for H-abstraction from <i>n</i>-pentanol by ȮH radicals is expressed as <i>k</i> = 3565.11 × <i>T</i>^2.93 exp (1465.44/<i>T</i>) (cm³ mol^-1 s^-1), and the data obtained at the CBS-QB3 level demonstrate good agreement with experimental observations. Furthermore, the original model is modified based on current results, and the improved model demonstrates superior predictive capabilities for jet-stirred reactor (JSR) data and ignition delay times. Reaction path and sensitivity analyses are employed to identify fuel consumption pathways and critical reactions in the combustion of <i>n</i>-pentanol.