A Kinetic study of the reaction of nitrogen dioxide with tetrafluoroethylene

Abstract

AbstractThe reaction of NO2 with C2F4 was studied at 30°, 68°, 114°, and 157°C by in situ monitoring the infrared absorption bands of the products. The major primary products of the reaction are O2NCF2CFO and FNO. Smaller amounts of CF2O (and presumably NO) are also produced. There was no evidence for other primary products, though they may have been produced in minor amounts. The rate laws for the production of both O2NCF2CFO and CF2O are first order in both [NO2] and [C2F4]. CF2O production is at least partly heterogeneous as demonstrated by packing the quartz reaction vessel with Pyrex beads and by using a Monel cell. The homogeneous rate constant obtained from the high‐temperature results gives a rate constant of 3.4 × 108 exp (minus;17000/RT) M−1sec−1 for CF2O production. Actually these Arrhenius parameters represent lower limits, since the heterogeneous reaction may still be playing a significant role. The production rate of O2NCF2CFO is not much affected by changing the nature of the surface or the surface to volume ratio. However the reaction may be heterogeneous, since the rate constant for its formation of 1.3 × 104 e×p (−7500/RT) M−1sec−1 has an abnormally low pree×ponential factor. E×periments in the presence of NO indicate that the mechanism for O2NCF2CFO formatlon is The intermediate can also react with NO: with k13/k12 = 1.3.