Atmosphere (Feb 2022)

Experimental and Theoretical Studies of Trans-2-Pentenal Atmospheric Ozonolysis

  • Carmen Kalalian,
  • Asma Grira,
  • Jan Niklas Illmann,
  • Iulia Patroescu-Klotz,
  • Gisèle El Dib,
  • Patrice Coddeville,
  • André Canosa,
  • Peter Wiesen,
  • Basheer Aazaad,
  • Lakshmipathi Senthilkumar,
  • Estelle Roth,
  • Alexandre Tomas,
  • Abdelkhaleq Chakir

DOI
https://doi.org/10.3390/atmos13020291
Journal volume & issue
Vol. 13, no. 2
p. 291

Abstract

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We investigated the kinetics, mechanism and secondary organic aerosols formation of the ozonolysis of trans-2-pentenal (T2P) using four different reactors with Fourier Transform InfraRed (FTIR) spectroscopy and Gas Chromatography (GC) techniques at T = 298 ± 2 K and 760 Torr in dry conditions. The rate coefficients and branching ratios were also evaluated using the canonical variational transition (CVT) state theory coupled with small curvature tunneling (CVT/SCT) in the range 278–350 K. The experimental rate coefficient at 298 K was (1.46 ± 0.17) × 10−18 cm3 molecule−1 s−1, in good agreement with the theoretical rate. The two primary carbonyls formation yields, glyoxal and propanal, were 57 ± 10% and 42 ± 12%, respectively, with OH scavenger compared to 38 ± 8% for glyoxal and 26 ± 5% for propanal without OH scavenger. Acetaldehyde and 2-hydroxypropanal were also identified and quantified with yields of 9 ± 3% and 5 ± 2%, respectively, in the presence of OH scavenger. For the OH production, an upper limit of 24% was estimated using mesitylene as OH tracer. Combining experimental and theoretical findings enabled the establishment of a chemical mechanism. Finally, the SOA formation was observed with mass yields of about 1.5%. This work provides additional information on the effect of the aldehyde functional group on the fragmentation of the primary ozonide.

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