HNO3 in water dissoln. of the molybdate and H3PO4 in H2O, kept at 333-343 K, pouring HNO3 into the soln. after cooling, pptn.; drying at 393 K overnight, then at 423 K for 14 h and at 453 K for 5 h, slowly heating (50°/h) to the final calcination temp. (640 K), detn. by X-ray diffraction and ionic chromy., elem. anal.;

NH4HCO3 in 1,4-dioxane; water stirring for 2 h; solid was filtered off, washed with cold water, dried at 120°C for 1 h; elem. anal.;

in neat (no solvent) direct reaction with excess of gaseous NH3 at 0°C followed by heating at 100°C; XRD, elem. anal.;

in solid heating at 200-400°C; monitoring by Raman spectroscopy;