Kinetic study of the OH and Cl-initiated oxidation, lifetimes and atmospheric acceptability indices of three halogenated ethenes.

JAVIER A. BARRERA, PABLO R. DALMASSO *, JUAN P. ARANGUREN ABRATE, RAÚL A. TACCONE, SILVIA I. LANE *

RSC Advances

Royal Society of Chemistry

Año: 2015 vol. 5 p. 73501 - 73501

2046-2069

he gas-phase kinetics for the reactions of OH radicals and Cl atoms with (E/Z)-CHCl=CHF, (E/Z)-CFCl=CFCl, and CCl2=CF2 were investigated at room-temperature and atmospheric pressure. A conventional relative-rate technique was used to determine the rate coefficients k(OH + (E/Z)-CHCl=CHF) = (6.3 ± 1.2) x 10-12, k(OH + (E/Z)-CFCl=CFCl) = (1.6 ± 0.2) x 10-12, k(OH + CCl2=CF2) = (5.0 ± 0.7) x 10-12, k(Cl + (E/Z)-CHCl=CHF) =(11 ± 2) x 10-11, k(Cl + (E/Z)-CFCl=CFCl) = (5.4 ± 1.3) x 10-11, and k(Cl + CCl2=CF2) = (6.3 ± 1.5) x 10-11 cm3 molecule-1 s-1. These rate coefficients were compared with previous literature data to analyze the effect of halogen substitution in ethenes on the reactivity towards OH and Cl, and used to estimate the global atmospheric lifetimes for the studied haloethenes. The calculated lifetimes, using average global concentrations of OH radicals and Cl atoms, indicate that the atmospheric loss of these compounds is determined by the OH-initiated oxidation. Also, the atm