Phosphoric Acid → Niobium phosphate

Temperature

150 °C

A mixture is prepared containing niobic acid, Nb2O5.xH2O, (60.33 g; 0.211 moles) and 85% phosphoric acid (602.20 g; 5.22 moles). The mixture is heated to 150° C. with stirring. The niobium oxide dissolves to form a pink solution, and upon further heating a precipitate forms. The precipitate is boiled in the phosphoric acid for about 2 hours. The mixture is cooled to room temperature, and the liquid is decanted from the precipitate. The precipitate is washed by adding 500 ml of water with stirring, after which the mixture 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 catalyst of niobium phosphate. The elemental analysis and X-ray diffraction spectrum of the catalyst are consistent with the composition NbOPO4.

1. customA mixture is prepared
2. additioncontaining niobic acid, Nb2O5
3. customto form a pink solution
4. temperatureupon further heating a precipitate forms
5. temperatureThe mixture is cooled to room temperature
6. customthe liquid is decanted from the precipitate
7. washThe precipitate is washed
8. additionby adding 500 ml of water
9. stirringwith stirring
10. filtrationafter which the mixture is filtered
11. filtrationThe washing and filtering cycle
12. customThe filtered solid is dried at 110° C. under air for 21/2 days

ORD record

ord-8ca0d0e1fc8c4cdab6a365133739765f

Source dataset

uspto-grants-1990_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04973569