Ammoxidation of 3-picoline over V2O5/MgF2 catalysts: Correlations between nicotinonitrile yield and O2 and NH3 chemisorption properties

V2O5/MgF2 catalysts with varying vanadia contents (V/Mg = 0.02–0.13) were prepared by impregnation and tested towards ammoxidation of 3-picoline to nicotinonitrile. The solids were characterised by BET-surface area determination, high temperature oxygen chemisorption and ammonia chemisorption. Both the O2 and NH3 uptakes were found to increase continuously with increase in V/Mg molar ratio of the catalysts. The catalytic activity changes in a similar fashion, while the nicotinonitrile selectivity is varied over a small range. Thus, direct correlations between the yield of nicotinonitrile and O2 and NH3 uptakes could be obtained. The catalyst with the highest V/Mg molar ratio displayed the best result giving 96% selectivity of nicotinonitrile at 91% conversion of 3-picoline.