The objective of this work is to understand the influence of small amount of Mo=O (1, 3 and 5wt.% MoO₃) impregnated on FePO₄ and its resultant effect on the acidity was studied for the ammoxidation of 2-methyl pyrazine (2-MP) to 2-cyano pyrazine (2-CP) in the temperature range of 380–420°C. The Mo/FeP catalyst characteristics were evaluated by XRD, HAADF-EDS, TPR and NH₃-TPD techniques. Primarily, quartz-type XRD phase was observed for the iron phosphate (FeP). The Mo/FeP exhibits MoO₃ and quartztype iron phosphate phase. The interface between Mo particles (20 nm) and FeP was clearly established by HR-TEM in 3Mo/FeP. Furthermore, the average atomic composition revealed by HAADF/EDS for 3Mo/FeP as Fe 30.0%, P 40.0% and Mo 1.6% with Fe/Mo surface XPS ratio 6. The greater 2-CP yield of 68.0% on 3Mo/FeP was attributed to enhanced, moderate acid sites coming from MoO₃ and cooperation between Mo and FeP at the interface in terms of oxygen and electron transfer to the reactant (2-MP).