Elucidating reaction pathways and kinetic modeling in ozone-assisted low-temperature oxidation of n-pentanol

Abstract

n-Pentanol (C₅H₁₁OH) is a versatile biofuel and fuel additive used to enhance combustion efficiency and reduce emissions when blended with gasoline. Ongoing research in alternative fuels explores the potential applications of n-pentanol. Understanding the low-temperature oxidation of n-pentanol is essential for developing combustion kinetic models to optimize engine performance and minimize pollutants when using this biofuel. Herein, we investigated the low-temperature oxidation of n-pentanol with ozone (O₃) in an atmospheric jet-stirred reactor. Ozone addition enhanced reactivity, leading to the formation of various products. High-mass-resolution mass spectra and photoionization curves identified reaction intermediates and products, particularly C₅ hydroxy keto-hydroperoxide was identified for the first time. Quantification of the measured intermediates and products allowed for updating the kinetic model of n-pentanol oxidation, improving predictions and validating ignition delay times. However, discrepancies existed for elusive intermediates like C₅H₈O₂ and C₅H₁₂O₂, prompting further exploration of their formation pathways. The findings provide insights into the chain-branching reaction pathways of n-pentanol at low temperatures and contribute to refining kinetic models for alcohol oxidation.