Mechanism and kinetics for the reaction of methyl peroxy radical with O2

Abstract

Quantum chemical calculations and dynamics simulations were performed to study the reaction between methyl peroxy radical (CH₃O₂) and O₂. The reaction proceeds through three different pathways (1) H-atom abstraction, (2) O₂ addition and (3) concerted H-atom shift and O₂ addition reactions. The concerted H-atom shift and O₂ addition pathway is the most favourable reaction both kinetically and thermodynamically. The major product channel formed from these reactions is H₂CO + OH + O₂. Trajectory calculations also confirm that H₂CO + OH + O₂ is the main product channel. An estimated rate constant expression for this reaction from master equation calculations is 4.20 × 10¹³ e^−8676/T cm³ mole⁻¹ s⁻¹.