Reaction between propionaldehyde and hydroxyperoxy radical in the atmosphere: A reaction route for the sink of propionaldehyde and the formation of formic acid. (1st September 2022)

• Record Type: Journal Article
• Authors: Ding, Da-Peng; Long, Bo
• Is Part Of: Atmospheric environment. Volume 284(2022)
• Publication Date: 2022-09-01
• Subjects: Aldehydes -- Hydroxyperoxy radical -- Formic acid -- Reaction kinetics; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2022.119202
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Understanding the chemical transformations of volatile organic compounds is particularly important for atmospheric modeling and elucidating their effects on atmospheric environment, where the key parameters are reaction mechanism and kinetics. Here, we report that the reaction mechanism and kinetics of propionaldehyde with hydroxyperoxy radical by using quantum chemical methods and reaction rate theory. In particular, we use our very recently developed dual-level strategy to obtain the high-pressure limit rate constants of the reaction of propionaldehyde (CH3 CH2 CHO) with hydroxyperoxy radical (HO2 ). We find that the enthalpy of activation at 0 K is only −1.86 kcal/mol in the CH3 CH2 CHO + HO2 reaction. The present results also uncover that the CH3 CH2 CHO + HO2 reaction depends on temperature and pressure and its high-pressure limit rate constant has negative temperature dependency with the value of 7.76 × 10 −13 to 3.06 × 10 −14 cm 3 molecules −1 s −1 at 190–350 K. Moreover, the present findings also show that the reaction of propionaldehyde with hydroxyperoxy radical can make great contribution to the sink of propionaldehyde below 260 K and 1 atm when OH concentration is less than 8.4 × 10 4 molecules cm −3 at night and can not be ignored at 0–10 km altitude. We also find a potential route for the formation of formic acid by the reaction of propionaldehyde with hydroxyperoxy radical. Graphical abstract: Image 1 Highlights: Theoretical methods are used to explore the reaction mechanism and kinetics of propionaldehyde with hydroxyperoxy radical. The reaction of propionaldehyde with hydroxyperoxy radical makes great contribution to the sink of propionaldehyde. Formic acid is produced in the reaction of propionaldehyde with hydroxyperoxy radical.