Kinetic and mechanistic study of the degradation of selected oxygenated volatile organic compounds (OVOCs) by atmospheric oxidants

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The overall aim of the present project is the investigation in a large volume photoreactor of the kinetics and mechanisms of the reactions of atmospheric oxidants with volatile organic compounds (VOCs), which have not previously been subject to in-depth investigation (alpha,beta-unsaturated oxygenates and cyclic oxygenates) with particular focus been placed on extending the investigations to atmospheric conditions to better understand peroxy radical chemistry at low-NO. The first objective of the work will be to obtain rate coefficients for the reactions of the selected alpha,beta-unsaturated oxygenates and cyclic oxygenates with OH and NO3 radicals, O3 and Cl atoms at room temperature using a relative kinetic technique.The second and more important objective is to perform kinetic and mechanistic investigations on the reactions of the oxidants with the selected alpha,beta-unsaturated oxygenates and cyclic oxygenates. The experiments will be performed differently to previous investigations. They will be performed under carefully chemically engineered high- and low-NO conditions to analyze how products and yields change as the lifetimes of the RO2 radicals, produced in the oxidant-mediated degradation of the compounds are regulated to levels approaching those prevalent in the troposphere. The aim is to develop mechanisms which are representative of not only high-NO tropospheric regimes but also low-NO regimes where peroxy radical chemistry will dominate and is currently poorly understood for the vast majority of VOCs.To support the low-NO product investigations high level quantum calculations for the peroxy radical chemistry in the reactions of the oxidants with representative alpha,beta-unsaturated oxygenates and cyclic oxygenates will be made.