Theoretical investigation of the mechanism, kinetics and subsequent degradation products of the NO3 radical initiated oxidation of acrolein

The explicit reaction mechanism and dynamics of acrolein (CH₂ = CHCHO) with NO₃ were studied using quantum chemistry methods. We examined the potential energy surface (PES) for H-abstraction reactions by NO₃ and NO₃ addition to the unsaturated carbon atoms in the CH₂ = CHCHO molecule. The PES analysis and thermochemical calculations reveal that NO₃-addition reactions and H-abstraction reactions are in competition with each other. The subsequent reactions of IM1 (CH₂ONO₂CHCHO), IM2 (CH₂CHONO₂CHO) and h-P3 were detailed investigated. The computed total rate constant increase with the temperature raising from 200 to 3000 K, and the rate constant is 1.43 × 10^{- 15} cm³ molecule^{- 1} s^{- 1} at 298 K, which is consistent with the experimental values. The lifetime of Acrolein oxidized by NO₃ radicals is estimated to be 14.20 days. Our theoretical investigations are of significant in understanding the oxidation process of unsaturated aldehyde by NO₃.