Solution Combustion Synthesis of Cr(2)O(3) Nanoparticles and the Catalytic Performance for Dehydrofluorination of 1,1,1,3,3-Pentafluoropropane to 1,3,3,3-Tetrafluoropropene

Cr(2)O(3) nanoparticles were prepared by solution combustion synthesis (SCS) with chromium nitrate as the precursor and glycine as the fuel. Commercial Cr(2)O(3) and Cr(2)O(3) prepared by a precipitation method were also included for comparison. The morphology, structure, acidity and particle size of fresh and spent Cr(2)O(3) catalysts were investigated by techniques such as XRD, SEM, TEM, BET and NH(3)-TPD. In addition, catalytic performance was evaluated for the dehydrofluorination of 1,1,1,3,3-pentafluoropropane (CF(3)CH(2)CHF(2), HFC-245fa) to 1,3,3,3-tetra-fluoropropene (CF(3)CH=CHF, HFO-1234ze). The catalytic reaction rate of Cr(2)O(3) prepared by SCS method is as high as 6 mmol/h/g, which is about 1.5 times and 2 times higher than that of precipitated Cr(2)O(3) and commercial Cr(2)O(3), respectively. The selectivity to HFO-1234ze for all the catalysts maintains at about 80%. Compared with commercial and precipitated Cr(2)O(3), Cr(2)O(3)-SCS prepared by SCS possesses higher specific surface area and acid amount. Furthermore, significant change in the crystal size of Cr(2)O(3) prepared by SCS after reaction was not detected, indicating high resistance to sintering.