Vanadium aluminium oxynitride catalyst for propane ammoxidation

High surface area vanadium aluminium oxynitrides (VAlON) prepared by nitridation of the amorphous oxide precursor exhibit a high acrylonitrile yield in the propane ammoxidation. It was found that their catalytic performances strongly depend on: (i) the amount of vanadium and (ii) the nitrogen content. The catalysts exhibited a remarkable activity with a maximum for V/Al of 0.25 in the presence of a molar ratio C3H8: O-2: NH3 of 1.25:3: 1. Under these conditions, the acrylonitrile selectivity and yield were 50% and 30%, respectively. These results could be explained by an optimal degree of nitridation and, further, an optimal reduction degree of vanadium.