Atmospheric Chemistry of CF ₃ C(Cl)═CH ₂ (HCFO‐1233xf)

ABSTRACT 2‐chloro‐3,3,3‐trifluoropropene, CF 3 C(Cl)═CH 2 (HCFO‐1233xf), is a volatile hydrochlorofluoroolefin, commonly used in industrial synthesis of other halogenated olefins. Kinetics and reaction mechanisms for the reactions of OH radicals, Cl atoms, and O 3 with CF 3 C(Cl)═CH 2 were investigated using FTIR/smog chamber studies in 700 Torr of air/N 2 diluent at 295 ± 2 K. The rate constants k (Cl + CF 3 C(Cl)═CH 2 ) = (8.3 ± 1.1) × 10 −11 , k (OH + CF 3 C(Cl)═CH 2 ) = (3.4 ± 0.8) × 10 −12 and k (O 3 + CF 3 C(Cl)═CH 2 ) = (2.5 ± 0.1) × 10 −21 cm 3 molecule −1 s −1 , were measured. An atmospheric lifetime of 3.3 days for CF 3 C(Cl)═CH 2 was determined, dominated by reaction with OH radicals. The reaction of OH radicals and Cl atoms with CF 3 C(Cl)═CH 2 proceeds by addition to the double bond, and primary and secondary products of the reactions were quantified. Approximately 90% of Cl atoms undergo addition to the terminal carbon. We were unable to establish any preference of reaction site of the OH addition. Reaction of O 3 with CF 3 C(Cl)═CH 2 leads to the formation of Criegee intermediates that decompose yielding CF 3 C(O)Cl and HC(O)H as major products. An upper limit of < 0.3% for the yield CF 3 Cl was estimated. The integrated IR absorption cross‐section for CF 3 C(Cl)═CH 2 is (1.22 ± 0.06) × 10 −16 cm molecule −1 (600–1800 cm −1 ). The effective radiative efficiency was determined as 0.007 W m −2 ppb −1 leading to a Global Warming Potential (GWP) for the 100‐year time horizon of 0.031. The environmental impact of release of CF 3 C(Cl)═CH 2 to the atmosphere is discussed.