反应详情

Niobic acid, Nb2O5 xH2O (60.33 g; 0.211 mole) is stirred in 85 percent phosphoric acid (602.20 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.

1. customto form a pink solution
2. temperatureupon further heating a precipitate forms
3. customthe liquid is decanted from the precipitate
4. additionWater (500 ml) is added to the precipitate
5. stirringwith stirring
6. filtrationthe precipitate is filtered
7. filtrationThe washing and filtering cycle
8. customThe filtered solid is dried at 110° C. under air for 21/2 days
9. customto yield a niobium phosphate catalyst