Atmospheric chemistry of perfluoronitriles: Environmental impact and experimental evidence related to N2O and NO formation

The atmospheric chemistry of perfluoronitriles, the proposed replacement gases of SF₆, has been investigated using an atmospheric reaction chamber. N₂O formation was first observed following the reaction between perfluoronitriles and OH radicals, then NO formation was verified through experimentation. COF₂, CF₃C(O)F, and CO₂ generation was observed, and a revised oxidation mechanism for perfluoronitriles in the atmosphere is proposed. Additionally, the rate coefficients related to OH radicals were measured for the perfluoronitriles of CF₃CN, CF₃CF₂CN, CF₃CF₂CF₂CN, and (CF₃)₂CFCN: their atmospheric lifetimes were 6.6, 10, 12, and 54 years, their radiative efficiencies were evaluated to be 0.188, 0.223, 0.317, and 0.231 W m^-2 ppb^-1, and their 100-year time horizon GWPs were 212, 374, 633, and 1705, respectively. The findings contained in this study indicate that perfluoronitriles present an insulating gas replacement option with a comparatively low environmental impact.