When CHClF 2 and CHF 3 are subjected to high-temperature, gas-phase flow pyrolysis in the presence of H 2 , they are converted, via a free radical chain mechanism, to CH 2 F 2 , CHF 2 CHF 2 , and CF 3 CH 2 F in good yield. Optimal conditions for pyrolysis of CHClF 2 involve a high conversion (92%) at 650 °C with an observed yield of products ) 18, 17, and 28%, respectively, whereas optimal conditions for CHF 3 involve a low conversion (24%) at 775 °C, but a higher yield of products (26, 6, and 39%, respectively).

The mechanism of the high-temperature, gas-phase isomerization of 1,1,2,2-tetrafluoroethane (FC-134) to 1,1,1,2-tetrafluoroethane (FC-134a) in the presence of H 2 has been explored both experimentally and computationally. Studies of the impact of temperature, H 2 /FC-134 ratio, and contact time on conversion and yield, as well as a study of deuterium incorporation when D 2 was used in place of H 2 , led to the conclusion that a free radical chain mechanism involving rearrangement of CHF 2 CF 2 ‚ to CF 3 CHF ‚ is involved.