Studies on the conversion of 1,1,1-trichlorotrifluoroethane, chloro-2,2,2-trifluoroethane, and 1,1,1-trifluoroethane by catalytic oxidation, hydrolysis and ammonolysis
Abstract
Catalytic hydrolysis and ammonolysis of CF3CCl3 (CFC-113a) and CF3CH2Cl (HCFC-133a) and oxidation of CF3CH3 (HFC-143a) were studied as possible routes to produce trifluoroacetic acid (TFA), trifluoroethanol (TFE) or trifluoroethylamine (TFEA), respectively. Catalysts employed in this study included oxides/halides of Fe, Pd, Cs, Cu, Sn, supported on carbon, Al2O3, ZrO2, TiO2, sulfated zirconia and fluoride supports like β-AlF3, and MgF2, as well as modified lanthanum phosphates. The reaction temperatures were varied from 100 to 450 °C, under these conditions CF3CCl3 and CF3CH2Cl could be hydrolysed giving trifluoroacetic acid or trifluoroethanol, respectively, in moderate yields, however all other reactions yielded predominantly CF2CHCl. Optimum conditions were identified for obtaining TFA over Fe/C catalyst by hydrolysis of CFC-113a, and for TFE by hydrolysis of HCFC-133a over alkaline modified lanthanum phosphate.