title: Investigation of the Gas-Phase Photolysis and Temperature-Dependent OH Reaction Kinetics of 4-Hydroxy-2-butanone.
abstract: Hydroxyketones are key secondary reaction products in the atmospheric oxidation of volatile organic compounds (VOCs). The fate of these oxygenated VOCs is however poorly understood and scarcely taken into account in atmospheric chemistry modeling. In this work, a combined investigation of the photolysis and temperature-dependent OH radical reaction of 4-hydroxy-2-butanone (4H2B) is presented. The objective was to evaluate the importance of the photolysis process relative to OH oxidation in the atmospheric degradation of 4H2B. A photolysis lifetime of about 26 days was estimated with an effective quantum yield of 0.08. For the first time, the occurrence of a Norrish II mechanism was hypothesized following the observation of acetone among photolysis products. The OH reaction rate coefficient follows the Arrhenius trend (280-358 K) and could be modeled through the following expression: k4H2B(T) = (1.26 ± 0.40) × 10(-12) × exp((398 ± 87)/T) in cm(3) molecule(-1) s(-1). An atmospheric lifetime of 2.4 days regarding the OH + 4H2B reaction was evaluated, indicating that OH oxidation is by far the major degradation channel. The present work underlines the need for further studies on the atmospheric fate of oxygenated VOCs.
authors.affiliation: Mines Douai , Département SAGE, 59500 Douai, France.|Université de Lille , 59655 Villeneuve d'Ascq, France.
authors.forename: Hichem
authors.initials: H
authors.lastname: Bouzidi
authors.affiliation: Mines Douai , Département SAGE, 59500 Douai, France.|Université de Lille , 59655 Villeneuve d'Ascq, France.
authors.forename: Lina
authors.initials: L
authors.lastname: Aslan
authors.affiliation: Institut de Physique de Rennes (IPR-Rennes), Département de Physique Moléculaire, UMR 6251 CNRS, 35042 Rennes, France.
authors.forename: Gisèle
authors.initials: G
authors.lastname: El Dib
authors.affiliation: Mines Douai , Département SAGE, 59500 Douai, France.|Université de Lille , 59655 Villeneuve d'Ascq, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Coddeville
authors.affiliation: Université de Lille, PhysicoChimie des Processus de Combustion et de l'Atmosphère (PC2A) UMR 8522 CNRS/Lille 1, Cité scientifique, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Christa
authors.initials: C
authors.lastname: Fittschen
authors.affiliation: Mines Douai , Département SAGE, 59500 Douai, France.|Université de Lille , 59655 Villeneuve d'Ascq, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Tomas
mesh_terms: D001272:Atmosphere; D002074:Butanones / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D010782:Photolysis; D013696:Temperature; D013997:Time Factors
chemical_list: D002074:Butanones; D005740:Gases; D017665:Hydroxyl Radical; C000597994:4-hydroxy-2-butanone