Influence of the morphology and of the composition of chromium oxides on their catalytic activity for the gas phase fluorination of 1,1,1-trifluoro-2-chloro-ethane. Preparation of hydrofluorocarbons Original Research Article

The morphology and the oxygen content of chromium oxides used in the fluorination of CF3CH2Cl are important parameters for their catalytic activity. The oxides constituted by polyhedral particles and particles in platelet shape have a catalytic activity per surface unit greater than the chromium oxides constituted by spheric and by needle particles. An excess of oxygen compared to CrO1.5 is necessary to obtain the highest intrinsic catalytic activity but the amount of the excess seems not to be important. Chromium oxides (CrO1.7 and CrO1.9) which have not the same oxygen excess have the same intrinsic catalytic activity.