Phosphoric Acid → Niobium phosphate

Temperature

150 °C

A mixture is prepared containing niobic acid, Nb2O5.xH2O, (60.33 g; 0.211 moles; Niobium Products Company, AD-460) 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 heating a precipitate forms. The precipitate is boiled in the phosphoric acid for about 2 hours. The boiled mixture is cooled to room temperature, and the liquid phase is decanted from the precipitate. The precipitate is washed by stirring with 500 ml of water, after which the aqueous 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 pattern of the catalyst are consistent with the composition NbOPO4. The P/Nb mole ratio, as determined by neutron activation analysis and X-ray fluorescence, is 1.03.

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

ORD record

ord-7f3b3d102ba04151a36fda8246789459

Source dataset

uspto-grants-1991_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05011999