Index Geophysics

Atmospheric degradation of 3-methylfuran: kinetic and products study

A study of the kinetics and products obtained from the reactions of 3-methylfuran with the main atmospheric oxidants has been performed. The rate coefficients for the gas-phase reaction of 3-methylfuran with OH and NO₃ radicals have been determined at room temperature and atmospheric pressure (air and N₂ as bath gases), using a relative method with different experimental techniques. The rate coefficients obtained for these reactions were (in units cm³ molecule⁻¹ s⁻¹) <i>k</i>_OH = (1.13 &plusmn; 0.22) &times; 10⁻¹⁰ and <i>k</i>_NO₃ = (1.26 &plusmn; 0.18) &times; 10⁻¹¹. Products from the reaction of 3-methylfuran with OH, NO₃ and Cl atoms in the absence and in the presence of NO have also been determined. The main reaction products obtained were chlorinated methylfuranones and hydroxy-methylfuranones in the reaction of 3-methylfuran with Cl atoms, 2-methylbutenedial, 3-methyl-2,5-furanodione and hydroxy-methylfuranones in the reaction of 3-methylfuran with OH and NO₃ radicals and also nitrated compounds in the reaction with NO₃ radicals. The results indicate that, in all cases, the main reaction path is the addition to the double bond of the aromatic ring followed by ring opening in the case of OH and NO₃ radicals. The formation of 3-furaldehyde and hydroxy-methylfuranones (in the reactions of 3-methylfuran with Cl atoms and NO₃ radicals) confirmed the H-atom abstraction from the methyl group and from the aromatic ring, respectively. This study represents the first product determination for Cl atoms and NO₃ radicals in reactions with 3-methylfuran. The reaction mechanisms and atmospheric implications of the reactions under consideration are also discussed.

Tapia, A.

Villanueva, F.

Salgado, M. S.

Cabañas, B.

Martínez, E.

Martín, P.

2018-01-15

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10.5194/acp-11-3227-2011

https://acp.copernicus.org/articles/11/3227/2011/

eISSN: 1680-7324

eng