Catalysts Studies On Fluorination From2-Chloro-3,3,3-Trifluoropropene To Tetrafluoropropene (HFC-1234yf, HFC-1234ze)

2,3,3,3-tetrafluoropropene (HFC-1234yf) has excellent environment parameters such as GWP=4and ODP=0, and less life cycle climate performance (LCCP). So, HFC-1234yf is considered as "direct substitution" economy plan for HFC-134a and could be a promising candidate for the third generation of refrigerants. In this paper, HFC-1234yf (2,3,3,3-tetrafluoropropene) was prepared by the material of HCFC-1233xf (2-chloro-3,3,3-trifluoropropene) and the products and raw materials tested by GC-MS2010. The phase structure and surface acid properties of the catalysts were characterized by XRD, Raman, NH3-TPD and BET techniques.Thermodynamics of the synthesis of2,3,3,3-tetrafluoropropene from1,1,2,3-tetrachloropropene was calculated, which was also applied to the conditions reported in published patents. The feasibility to the methord of the synthesis of2,3,3,3-tetrafluoropropene from1,1,2,3-tetrachloropropene was analysisd in this paper by thermodynamics calculate.Cr2O3catalysts 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 results show with increasing calcination temperature, the crystalline size of Cr2O3catalysts increases while the amount of surface acid sites decrease, which leads to the increase of the specific rate of fluorination of HCFC-1233xf. However, the catalyst calcined at500℃shows the highest activity, with the HCFC-1233xf conversion of63.3%, and the selectivities to HFC-1234yf and HFC-245eb of59and38%, respectively. The carbon deposit on the surface of the catalysts may be the main reason for the deactivation of the catalyst during the reaction.X-Cr2O3(Co,Ga,Mg,Fe,Zn)catalysts were prepared by co-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 promoter on the catalytic performance. The results show that the amount of surface acid sites increase while adding the promoter in catalysts, which leads to the decrease of the specific rate of fluorination of HCFC-1233xf. It was found that the additive agents of Fe-Cr2O3exhibited the highest selectivies to HFC-1234yf and HFC-245eb (1,1,1,2,3-pentafluoropropane) of71%and19.6%, respectively, at a reaction temperature of320℃. Moreover, it was found that the carbon deposit on the surface was responsible for the deactivation of the catalyst during the reaction.Because of the main products are HFC-1234ze on Ru/C catalysts and the main products are HFC-1234yf and HFC-245eb on chromium-based catalysts, the reaction mechanism on different catalysis was found.