Kinetic and mechanistic study of the degradation of selected oxygenated volatile organic compounds (OVOCs) by atmospheric oxidants

• Applicant: Professor Dr. Peter Wiesen
• Subject Area: Atmospheric Science ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 356235213

• Final Report Year: 2023

Final Report Abstract

Oxygenated (= oxygen-containing) hydrocarbons (OVOCs) are ubiquitous trace gases in the troposphere either emitted into the atmosphere or formed in situ through the oxidation of precursor species. They contribute to the formation of particles and hence affect the Earth’s radiative budget. Due to the multiplicity of possible species, there is still a need for systematic investigations on the oxidation of OVOCs, particularly under conditions where the reaction of so-called peroxy radicals (RO2) with nitrogen monoxide is no longer dominating. In the present project the oxidation of compound classes was investigated, for which the data pool is scarce or missing. One major focus was the ozonolysis of unsaturated OVOCs. Based on systematic investigations of a series of unsaturated ketones it was shown that the ozonolysis of this compound class produces organic acids such as formic and acetic acid in surprisingly high yields. This is particularly important for methyl vinyl ketone, which is one of the major products of the isoprene oxidation. Due to the emission strength of isoprene the ozonolysis of methyl vinyl ketone turns out as a globally non-negligible source of organic acids in the atmosphere, which appears overlooked to date.

Publications

• Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (E)-4-methoxy-3-buten-2-one and (1E)-1-methoxy-2-methyl-1-penten-3-one. Atmospheric Chemistry and Physics, 20(14), 8939-8951.
  Gibilisco, Rodrigo Gastón; Barnes, Ian; Bejan, Iustinian Gabriel & Wiesen, Peter
  
• Atmospheric oxidation of α,β-unsaturated ketones: kinetics and mechanism of the OH radical reaction. Atmospheric Chemistry and Physics, 21(17), 13667-13686.
  Illmann, Niklas; Gibilisco, Rodrigo Gastón; Bejan, Iustinian Gabriel; Patroescu-Klotz, Iulia & Wiesen, Peter
  
• Biomass burning plume chemistry: OH-radical-initiated oxidation of 3-penten-2-one and its main oxidation product 2-hydroxypropanal. Atmospheric Chemistry and Physics, 21(24), 18557-18572.
  Illmann, Niklas; Patroescu-Klotz, Iulia & Wiesen, Peter
  
• FTIR kinetic study of the reactions of γ-caprolactone and γ-heptalactone initiated by Cl and OH radicals at 298 K and atmospheric pressure. Chemical Physics Letters, 765, 138313.
  Baptista, Andrea; Gibilisco, Rodrigo G.; Wiesen, Peter & Teruel, Mariano A.
  
• Gas-phase reactivity of acyclic α,β-unsaturated carbonyls towards ozone. Physical Chemistry Chemical Physics, 23(5), 3455-3466.
  Illmann, Jan Niklas; Patroescu-Klotz, Iulia & Wiesen, Peter
  
• Organic acid formation in the gas-phase ozonolysis of α,β-unsaturated ketones. Physical Chemistry Chemical Physics, 25(1), 106-116.
  Illmann, Niklas; Patroescu-Klotz, Iulia & Wiesen, Peter
  
• Product study of the reactions of γ-caprolactone and γ-heptalactone initiated by OH radicals at 298 K and atmospheric pressure: Formation of acyl peroxynitrates (APN).. Chemosphere, 323, 138156.
  Baptista, Andrea; Gibilisco, Rodrigo G.; Patroescu-Klotz, Iulia; Illmann, Niklas; Wiesen, Peter; Blanco, María B. & Teruel, Mariano A.