a process is disclosed for making cf 3 cf ═ chf . the process involves contacting at least one hexafluoropropane selected from the group consisting of cf 3 cf 2 ch 2 f and cf 3 chfchf 2 with a chromium oxyfluoride catalyst in a reactor to obtain a product mixture comprising cf 3 cf ═ chf , and recovering cf 3 cf ═ chf from the product mixture . a process is disclosed for making cf 3 ch ═ chf . the process involves contacting cf 3 ch 2 chf 2 with a chromium oxyfluoride catalyst in a reactor to obtain a product mixture comprising cf 3 ch ═ chf , and recovering cf 3 ch ═ chf from the product mixture . a process is disclosed for making cf 3 cf ═ ch 2 . the process involves contacting cf 3 cf 2 ch 3 with a chromium oxyfluoride catalyst in a reactor to obtain a product mixture comprising cf 3 cf ═ ch 2 , and recovering cf 3 cf ═ ch 2 from the product mixture .