Atmospheric Chemistry of Benzyl Alcohol: Kinetics and Mechanism of Reaction with OH Radicals

摘要

The atmospheric oxidation of benzyl alcohol has been investigated using smog chambers at ICARE, FORD, and EUPHORE. The rate coefficient for reaction with OH radicals was measured and an upper limit for the reaction with ozone was established; k_(OH) = (2.8 ± 0.4) × 10~(-11) at 297 ± 3 K (averaged value including results from Harrison and Wells) and k_(O3) ＜ 2 × 10~(-19) cm~3 molecule~(-1) s~(-1) at 299 K. The products of the OH radical initiated oxidation of benzyl alcohol in the presence of NO_X were studied. Benzaldehyde, originating from H-abstraction from the -CH_2OH group, was identified using in situ FTIR spectroscopy, HPLC-UV/FID, and GC-PID and quantified in a yield of (24 ± 5) %. Ring retaining products originating from OH-addition to the aromatic ring such as o- hydroxybenzylalcohol and o-dihydroxybenzene as well as ring-cleavage products such as glyoxal were also identified and quantified with molar yields of (22 ± 2)%, (10 ± 3)%, and (2.7 ± 0.7)%, respectively. Formaldehyde was observed with a molar yield of (27 ± 10)%. The results are discussed with respect to previous studies and the atmospheric oxidation mechanism of benzyl alcohol.