Journal of Physical Chemistry A, Vol.122, No.6, 1600-1611, 2018
Gas-Phase Oxidation of Allyl Acetate by O-3, OH, CI, and NO3: Reaction Kinetics and Mechanism
Allyl acetate (AA) is widely used as monomer and intermediate in industrial chemicals synthesis. To evaluate the atmospheric outcome of AA, kinetics and mechanism of its gas phase reaction with main atmospheric oxidants (O-3, OH, Cl, and NO3) have been investigated in a Teflon reactor at 298 3 K. Both absolute and relative rate methods were used to determine the rate constants for AA reactions with the four atmospheric oxidants. The obtained rate constants (in units of cm(3) molecule' s(-1)) are (1.8 +/- 0.3) x 10(-18), (3.1 +/- 0.7) X 10(-11), (2.5 +/- 0.5) x 10(-16), and (1.1 +/- 0.4) x 10-(14), for reactions with O-3, OH, Cl, and NO3, respectively. While results for reactions with O-3, OH and Cl are in good agreement with previous studies, the kinetics for the reaction with NO3 is reported for the first time in this study. On the basis of determined rate constants, the tropospheric lifetimes of AA are tau(O3) = 9 days, tau(OH) = 5 h, tau(CI) = 5 days, tau NO3, = 2 days. On the basis of the products study, reaction mechanisms for these oxidations have been proposed and the reaction products were detected using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and Fourier transform infrared spectroscopy (FTIR). Results show that the main products formed in these reactions are carbonyl compounds. In particular, 2-oxoethyl acetate was detected in all four AA oxidation reactions. Compared to previous studies, several new products were determined for reactions with OH and Cl. These results form a set of comprehensive kinetic data for AA reactions with main atmospheric oxidants and provide a better understanding of the degradation and atmospheric outcome of unsaturated acetate esters in the troposphere, during both daytime and nighttime.