The mechanism and kinetic studies on oxidation reaction of acetofenate initiated by HOx, NO3, O3, and Cl radicals

Abstract

Acetofenate (AF) is a widely used pesticide. The mechanism of HO_x, NO₃, O₃, and Cl initiated oxidation reactions of AF was investigated with density functional theory. For each of the OH, NO₃, and Cl, both addition and hydrogen abstraction were investigated, for each of the HO₂ radicals and O₃, addition reactions were investigated. The cycloaddition reactions of O₃ were considered, including the exploration of isomerization. Based on the potential energy surface, the rate constants were calculated with the transition state theory method over a temperature range of 200–400 K and fitted with the Arrhenius formulas. The rate constants of the AF reaction with OH, HO₂, NO₃, O₃, and Cl, are 4.04 × 10⁻¹³, 7.02 × 10⁻³³, 6.93 × 10⁻²⁰, 1.45 × 10⁻²⁵, and 5.07 × 10⁻¹² cm³ per molecule per s at 298.15 K, respectively. The OH-initiated reactions are dominant according to the branching ratio of reaction constants. The atmospheric lifetime of the reaction species was estimated according to rate constants.