Synthesis of 2,3,3,3-tetrafluoropropene by catalytic dehydrofluorination of 1,1,1,3,3-pentafluoropropane over Ni-Cr2O3 catalyst

摘要

2,3,3,3-Tetrafluoropropene (HFO-1234yf) has been synthesized from 1,1,1,3,3-pentafluoropropane (HFC-245fa) by dehydrofluorination over a series of Ni-Cr2O3 catalysts. HFC-245fa could be readily dehydrofluorinated to HFO-1234yf and 1,3,3,3-tetrafluoropropene (HFO-1234ze) over these catalysts. Characterization results reveal that the Ni species in the catalysts is mainly metallic. Ammonia temperature-programmed desorption results indicate that the surface acidity is enhanced with increasing Ni contents in the catalysts, which is responsible for the increased selectivity towards HFO-1234yf. The formation of carbon during the reaction led to the coverage of surface acidic sites, which accounted for the decrease of the selectivity to HFO-1234yf.