Effect of multifunctional compound monoethanolamine on Criegee intermediates reactions and its atmospheric...

The reactions of Criegee intermediates with trace gases (such as alcohols, amines, and acids) are primarily dependent on the trace gases' functional group activity. In this study, we used density functional theory calculations and ab initio dynamics simulation methods to explore the synergistic effect of NH₂ and OH groups, in the multifunctional compound monoethanolamine (MEA), on the Criegee reaction. The results showed that among the four evaluated MEA configurations, two functional groups in the g'Gg' and tGg' configurations, -NH₂ and -OH, have the synergistic effect on the C2 stabilized Criegee intermediates (sCIs). At the gas-liquid interface, sCIs react with NH₂ groups of MEA molecules directly or are mediated by water molecules, resulting in additional product formation. The rate calculation indicated that the reaction of sCIs with NH₂ groups of MEA molecules is prior to that with OH groups. In addition, OH groups promote the reactions between sCIs and NH₂ groups of MEA, while the presence of NH₂ groups weakens the reactions of sCIs and OH groups of MEA to some extent. At 298 K, the total rate constant of anti-CH₃CHOO with NH₂ group of MEA is 4.26 × 10^-11 cm³ molecule^-1 s^-1, which is four orders of magnitude higher than that of anti-CH3CHOO hydration. Under low humidity conditions, the reactions between sCIs and MEA could contribute to the removal of sCIs.