Polyoxometalate and method for producing polyoxometalate
Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M x O y in which M is tungsten, molybdenum or vanadium; 4≤x≤1000; and 2.5≤y/x≤7.
1. A method for producing a polyoxometalate, comprising:
subjecting a raw material mixture comprising at least one valuable containing tungsten, molybdenum or vanadium to electrolysis using an organic electrolytic solution containing at least one alcohol amine to dissolve tungsten, molybdenum or vanadium in the electrolytic solution; and
adding a poor solvent including an alcohol, an acetone, an ether, an amine or an ester to the electrolytic solution in which tungsten, molybdenum or vanadium has been dissolved, to produce a precipitate of a polyoxometalate of tungsten, molybdenum or vanadium.
2. The method for producing the polyoxometalate according to claim 1 , wherein the at least one alcohol amine is monoethanolamine and/or triethanolamine.
3. The method for producing the polyoxometalate according to claim 1 , wherein a concentration of the alcohol amine in the electrolytic solution is from 1 to 80% by mass.
4. The method for producing the polyoxometalate according to claim 1 , wherein the raw material mixture contains from 1 to 30% by mass of at least one valuable other than tungsten, molybdenum or vanadium.
5. The method for producing the polyoxometalate according to claim 4 , wherein the raw material mixture contains from 1 to 10% by mass of at least one valuable other than tungsten, molybdenum or vanadium.
6. The method for producing the polyoxometalate according to claim 5 , wherein the raw material mixture contains from 3 to 10% by mass of at least one valuable other than tungsten, molybdenum or vanadium.
7. The method for producing the polyoxometalate according to claim 1 , wherein the electrolysis is carried out by adjusting a temperature of the electrolytic solution to 20 to 80° C.
8. The method for producing the polyoxometalate according to claim 1 , wherein the electrolytic solution has a pH of 7 or more.
9. The method for producing the polyoxometalate according to claim 1 , wherein an anode used for the electrolysis is a titanium basket provided with the raw material mixture containing the at least one valuable containing tungsten, molybdenum or vanadium.
10. The method for producing the polyoxometalate according to claim 1 , wherein the organic electrolytic solution is an organic alkaline electrolytic solution.
11. The method for producing the polyoxometalate according to claim 2 , wherein a concentration of the alcohol amine in the electrolytic solution is from 1 to 80% by mass.
12. The method for producing the polyoxometalate according to claim 1 , wherein the raw material mixture contains from 1 to 30% by mass of at least one valuable other than tungsten.
13. The method for producing the polyoxometalate according to claim 1 , wherein the raw material mixture contains from 1 to 30% by mass of at least one valuable other than molybdenum.
14. The method for producing the polyoxometalate according to claim 1 , wherein the raw material mixture contains from 1 to 30% by mass of at least one valuable other than vanadium.
15. The method for producing the polyoxometalate according to claim 2 , wherein the raw material mixture contains from 1 to 30% by mass of at least one valuable other than tungsten, molybdenum or vanadium.