Parameters influencing the synergetic effect induced by vanadium incorporation on non-conventional (Al)(Ga)PO supports for the propane ammoxidation

A series of V-oxide supported catalysts (5V/AlPO₄, 5V/Al_0.5Ga_0.5PO₄, 5V/GaPO₄) were prepared in order to study their catalytic behaviour in the ammoxidation of propane. Catalysts were characterized by BET surface area, XRD, Raman spectroscopy, TPR-H₂ and XPS. The presence of vanadium induced the crystallization of the supports (AlPO₄, Al_0.5Ga_0.5PO₄ and GaPO₄). Crystalline V₂O₅ was observed on the V-based catalysts. Catalytic results showed that the impregnation of vanadium enhances the propane conversion and selectivity to acrylonitrile (ACN). At 530 °C 5V/Al_0.5Ga_0.5PO₄ exhibits the highest selectivity to ACN. One assumes that the best performance of 5V/Al_0.5Ga_0.5PO₄ in propane ammoxidation, is due to on the one hand the easiest reduction of V₂O₅ on Al_0.5Ga_0.5PO₄ and to on the other hand a certain tunability of the reduced species stabilized on Al_0.5Ga_0.5PO₄.