Catalysis Letters, Vol.83, No.3-4, 127-132, 2002
In situ synthesis of the ammonium salt of 12-molybdophosphoric acid on niobium phosphate by salt-surface interaction: The ammoxidation functionality of the catalyst in the transformation of 2-methylpyrazine to 2-cyanopyrazine
The ammonium slat of 12-molybdophosporic acid (AMPA) has been synthesized, in situ, on niobium phosphate by interacting the phosphate of the support with the molybdenum of the salt. The formation of AMPA, with the popular Keggin structure, is confirmed by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The in situ synthesized catalysts exhibited higher ammoxidation activity than the bulk AMPA, showing optimum conversion at 10 wt% Mo loading. The selectivity to nitrile increased with increasing loading.
Keywords:ammonium salt of 12-molybdophosphoric acid;ammoxidation of methylpyrazine;salt-surface interaction