Characterization and catalytic properties of molybdenum oxide catalysts supported on ZrO2-γ-Al2O3 for ammoxidation of toluene

Molybdenum oxide catalysts with MoO3 loadings ranging from 6.6 to 25 wt% supported on ZrO2-gamma-Al2O3 (1 : 1 wt%) mixed oxide were prepared by a wet impregnation method. The catalytic behavior of catalysts in the toluene ammoxidation reaction was investigated in a lab-scale tube reactor at 400 degrees C. The catalytic performance of MoO3/ZrO2-gamma-Al2O3 was dependent on the catalyst compositions and reaction temperature. MoO3 (20.0 wt%) ZrO2-gamma-Al2O3 exhibited a good toluene oxidation; over this catalyst, the selectivity to benzonitrile reached 67.0% with a toluene conversion of 68.5% at 400 degrees C, while the selectivity to benzaldhyde was 24.4% with a toluene conversion of 68.5% at 400 degrees C. The catalysts were characterized by various techniques, such as N-2 sorption, FTIR, SEM and XRD.