Gas-phase epoxidation of 3,3,3-trifluoropropylene over Au/Cusingle bondTiO2 catalysts with N2O as the oxidant

Gas-phase epoxidation of 3,3,3-trifluoropropylene (TFP) was conducted on a series of Au/Cusingle bondTiO2 catalysts with different Cu contents with N2O as the oxidant. These catalysts were effective for this reaction. The best catalytic performance was obtained on a catalyst containing 4.6 wt.% of Au and 0.9 wt.% of Cu (4.6Au/0.9Cusingle bondTiO2), with a steady-state 3,3,3-trifluoropropylene oxide (TFPO) formation rate of image, which was much higher than that on a 2.1Au/TiO2 catalyst (image). The enhancement was attributed to the higher Au content in the Cu-promoted catalyst and small Au particle size and more importantly to the complicated synergy between the Ausingle bondCusingle bondTiO2 interaction which might be the active sites for epoxidation. Also, high selectivity to TFPO up to 88% was obtained on the Cu-promoted catalyst, due to the proper electronic structure induced by the interaction between Au and low valent Cu species. Catalyst deactivation was due to the significant growth of Au particles and loss of Ausingle bondCusingle bondTiO2 interface because of the segregation of Cu species during the reaction.