Phosphoric Acid → Niobium phosphate

Participants

Reaction Steps

Niobic acid, Nb2O5 ·xH2O (60.33 g; 0.211 mole) is stirred in 85 percent phosphoric acid (600 g; 5.22 moles) at 150° C. The niobium oxide dissolves to form a pink solution, and upon further heating a precipitate forms. The precipitate is boiled in the phosphoric acid solution for about 2 hours with stirring. The mixture is cooled to room temperature, and the liquid is decanted from the precipitate. Water (500 ml) is added to the precipitate with stirring, and the precipitate is filtered. The washing and filtering cycle is repeated five times. The filtered solid is dried at 110° C. under air for 21/2 days to yield a niobium phosphate catalyst. The elemental analysis of the catalyst is consistent with the composition NbOPO4.

Provenance & Evidence