Formation of Organic Acids and Carbonyl Compounds in n-Butane Oxidation via γ-Ketohydroperoxide Decomposition.

Autor: Popolan-Vaida DM; Department of Chemistry and Physics, University of California, Berkeley, Berkeley, CA 94720, USA.; Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA., Eskola AJ; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.; Department of Chemistry, University of Helsinki, 00014, Helsinki, Finland., Rotavera B; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.; Department of Chemistry and College of Engineering, University of Georgia, Athens, GA 30602, USA., Lockyear JF; Department of Chemistry and Physics, University of California, Berkeley, Berkeley, CA 94720, USA., Wang Z; King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Thuwal, 23955-6900, Saudi Arabia.; National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China., Sarathy SM; King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Thuwal, 23955-6900, Saudi Arabia., Caravan RL; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.; Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA., Zádor J; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA., Sheps L; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA., Lucassen A; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.; Physikalisch-Technische Bundesanstalt, 38116, Braunschweig, Germany., Moshammer K; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.; Physikalisch-Technische Bundesanstalt, 38116, Braunschweig, Germany., Dagaut P; Centre National de la Recherche Scientifique (CNRS), INSIS, ICARE, 45071, Orléans Cedex 2, France., Osborn DL; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA., Hansen N; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA., Leone SR; Department of Chemistry and Physics, University of California, Berkeley, Berkeley, CA 94720, USA., Taatjes CA; Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2022 Oct 17; Vol. 61 (42), pp. e202209168. Date of Electronic Publication: 2022 Sep 14.
DOI: 10.1002/anie.202209168
Abstrakt: A crucial chain-branching step in autoignition is the decomposition of ketohydroperoxides (KHP) to form an oxy radical and OH. Other pathways compete with chain-branching, such as "Korcek" dissociation of γ-KHP to a carbonyl and an acid. Here we characterize the formation of a γ-KHP and its decomposition to formic acid+acetone products from observations of n-butane oxidation in two complementary experiments. In jet-stirred reactor measurements, KHP is observed above 590 K. The KHP concentration decreases with increasing temperature, whereas formic acid and acetone products increase. Observation of characteristic isotopologs acetone-d 3 and formic acid-d 0 in the oxidation of CH 3 CD 2 CD 2 CH 3 is consistent with a Korcek mechanism. In laser-initiated oxidation experiments of n-butane, formic acid and acetone are produced on the timescale of KHP removal. Modelling the time-resolved production of formic acid provides an estimated upper limit of 2 s -1 for the rate coefficient of KHP decomposition to formic acid+acetone.
(© 2022 Wiley-VCH GmbH.)
Databáze: MEDLINE
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