Influence of ammonium salt formation on the activity and selectivity of the 12-molybdophosphate heteropolyacid catalyst prepared by solid-solid interaction in the ammoxidation of 2-methylpyrazine

The ammonium salt of 12-molybdophosphoric acid has been prepared by the sol id-state interaction of the ammonium salts of molybdenum and phosphorus. Th e catalysts obtained by pretreatment of the precursor at various temperatur es, have been characterized by nitrogen adsorption, X-ray diffraction (XRD) , Fourier-transformed infrared (FTIR) spectroscopy and temperature-programm ed decomposition (TPD) of the catalysts. Ammoxidation of 2-methylpyrazine h as been carried out on these catalysts. The amount of ammonium salt present in the catalyst has been correlated with the activity and selectivity of t he catalysts.