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Chemical Kinetics for a
Sustainable Future

Book of Abstracts

13th International Conference on Chemical Kinetics

June 8th-13th, 2025

Granlibakken Tahoe Resort in Tahoe City, California
Constraining the low-temperature oxidation mechanism of *n*-hexanol
through the detection and identification of C<sub>6</sub> elusive intermediates

Y. Zhai<sup>a</sup>, A. C. DeCecco<sup>a</sup>, A. W. Jasper<sup>b</sup>, N. Hansen<sup>c</sup>, P. Dagaut<sup>d</sup>, G. Villalobos<sup>a</sup>, and D. M. Popolan-Vaida<sup>a</sup>

<sup>a</sup> Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA
(Yitong.zhai@ucf.edu)

<sup>b</sup> Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439,
USA

<sup>c</sup>Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA

<sup>d</sup>Centre National de la Recherche Scientifique (CNRS), ICARE, 1C Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France

Alcohol-based fuels are currently considered viable energy carriers for the transportation sector. Consequently, a comprehensive mechanistic understanding of the low-temperature oxidation of alcohols is essential for application in advanced low-temperature compression engines. A multidimensional approach involving experimental investigations, kinetic modeling, and theoretical calculations was used to provide new insights into the low-temperature oxidation mechanism of a C<sub>6</sub> alcohol, n-hexanol (CH<sub>3</sub>(CH<sub>2</sub>)<sub>5</sub>OH), through the detection and identification of elusive C<sub>6</sub> intermediates. The oxidation of n-hexanol was investigated in a jet-stirred reactor (JSR) under stoichiometric conditions (φ = 1.0), an initial fuel concentration of 2%, a residence time of 2 s, a temperature range between 500 K - 660 K, and a pressure of 700 Torr. The reactants, intermediates, and final products were detected and identified by means of molecular-beam mass spectrometry coupled with single-photon ionization employing tunable synchrotron-generated vacuum ultraviolet radiation. Chemical kinetic simulations were performed using a previously published kinetic model (Togbé et al., *Energy Fuels* 11, 5859–5875, (2010)) to predict the reactivity of *n*-hexanol and elucidate the predominant formation pathways of the observed low-temperature species. Experimental photoionization efficiency curves in conjunction with *ab initio* calculations, enabled the identification of important low-temperature species, such as C<sub>6</sub> unsaturated alcohols, C<sub>6</sub> olefinic hydroperoxides, C<sub>6</sub> cyclic ethers, C<sub>6</sub> diones, and C<sub>6</sub> ketohydroperoxides. The results of this study provide valuable insight into the mechanism of low-temperature oxidation chemistry of n-hexanol, contributing to the development of kinetic models for the low-temperature oxidation of n-hexanol and other long-chain linear alcohols.