Cr 2 O 3 catalysts were prepared by a precipitation method and tested for vapor phase fluorination of HCFC-1233xf (2-chloro-3,3,3-trifluoropropene) to HFC-1234yf (2,3,3,3-tetrafluoropropene) to investigate the effect of calcination temperature on the catalytic performance. The catalysts were characterized by XRD, Raman, NH 3 -TPD, and BET techniques. The results show, with increasing calcination temperature, the crystallite size of the catalyst increased while the surface acid sites decreased. It was found that the catalyst calcined at 500 °C exhibited the highest catalytic activity, with a HCFC-1233xf conversion of 63.3% and selectivies to HFC-1234yf and HFC-245eb (1,1,1,2,3-pentafluoropropane) of 59 and 38%, respectively, at a reaction temperature of 320 °C. Moreover, it was found that the carbon deposit on the surface was responsible for the deactivation of the catalyst during the reaction.

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Amorphous Cr2O3 materials with high surface areas were prepared via a precipitation process with CrCl3 · 6H2O as the raw material, (NH4)2CO3, NH3 · H2O, and KOH as precipitating agents. Calcination of Cr(OH)3 precipitation at low temperatures (300–400 °C) resulted in amorphous Cr2O3 materials with high surface areas, while high‐temperature calcination (500–600 °C) led to crystalline Cr2O3. The hydrogen‐adsorption phenomenon was clearly observed in a hydrogen atmosphere on the amorphous Cr2O3 materials with high surface area. The adsorbed hydrogen desorbed at about 550 °C due to the phase transition from amorphous to crystalline. However, this phenomenon was not observed for crystalline Cr2O3.