Synthetic methods for the preparation of propylene ammoxidation catalysts

1. A process for producing a catalyst material, the catalyst material comprising

a metal oxide catalyst in an amount in the range of at least about 25 wt %, the metal oxide catalyst having the formula Mo x Bi y Fe z A a B b C c D d O v , wherein

x is in the range of 10 to 14;

y is in the range of 0.05 to 5;

z is in the range of 0.2 to 5;

A is at least one element selected from Ni and Co;

a is in the range of 1 to 10;

B is at least one element selected from the lanthanides, Mg, Cr, Mn, Zn and Ca;

b is in the range of 0.01 to 6;

C is at least one element selected from W, Sn, V, Ti, Zr, Ga, Hf, Nb, Ta, In and Al;

c is in the range of 0 to 8;

D is at least one element selected from Li, Na, K, Rb and Cs;

d is in the range of 0.02 to 2; and

v is the number of oxygen atoms required to satisfy the valence requirements of the other component elements Mo, Bi, Fe, A, B, C, and D,

the process comprising:

providing a suspension or slurry of an inert carrier in a metal oxide precursor fluid, the inert carrier having an average particle size less than about 10 microns, the metal oxide precursor fluid comprising a solvent in admixture with a plurality of metal oxide precursors, the plurality of metal oxide precursors comprising at least

a molybdenum oxide precursor,

a bismuth oxide precursor, and

an iron oxide precursor,

wherein less than about 5 wt % of each of the molybdenum oxide precursor, the bismuth oxide precursor, and the iron oxide precursor is not dissolved in the solvent;

spray drying the suspension or slurry of the inert carrier in the metal oxide precursor fluid to obtain a spray-dried precursor material; and

heating the spray-dried precursor material to obtain the catalyst material.

2. The process of claim 1 , wherein each of the molybdenum oxide precursor, the bismuth oxide precursor, and the iron oxide precursor are essentially completely dissolved in the solvent.

3. The process of claim 1 , wherein the catalyst material further comprises an inert carrier, and wherein the inert carrier is combined with the metal oxide precursor fluid to provide a suspension or slurry of the inert carrier in the metal oxide precursor fluid.

4. The process of claim 1 , wherein less than about 1 wt % of each of the molybdenum oxide precursor, the bismuth oxide precursor, and the iron oxide precursor is not dissolved in the solvent.

5. The process of claim 1 , wherein the molybdenum oxide precursor is provided as a heptamolybdate.

6. The process of claim 1 , wherein the solvent is an aqueous organic acid selected from glycolic acid, acetic acid, lactic acid and mixtures thereof, at a concentration in the range of 45-90 wt %.

7. The process of claim 1 , wherein providing a metal oxide precursor fluid comprises:

dissolving a molybdenum oxide precursor and a bismuth oxide precursor in the solvent to obtain a clear solution; and

adding the iron oxide precursor and optionally one or more metal oxide precursors to the clear solution.

8. The process of claim 1 , wherein heating includes calcination in the presence of air at a temperature of about 200° C. to about 700° C.

9. The process of claim 1 , wherein the inert carrier and the metal oxide catalyst are together present in the catalyst material in an amount of at least about 90 wt %.

10. The process of claim 1 , wherein the inert carrier is selected from SiO 2 , Al 2 O 3 , ZrO 2 , Nb 2 O 5 , TiO 2 , HfO 2 , Ta 2 O 5 , Sb 2 O 5 , and their mixed oxides.

11. The process of claim 1 , wherein x is 12.

12. The process of claim 1 , wherein

A is Ni, or A is Co, or A is a combination of Ni and Co;

B is at least one element selected from Ce, Mg, Cr, Mn, Zn and Ca;

C is at least one element selected from Sn, V, Ti, Zr, Ga, Hf, Nb, Ta, In and Al; and

D is at least one element selected from Li, K and Cs, and

wherein the material does not include W.

13. The process of claim 1 , wherein c is substantially zero.

14. The process of claim 1 , wherein the metal oxide catalyst has the formula Mo x Bi y Fe z Ni a Ce b1 Mg b2 Mn b3 K d1 Cs d2 O y , in which x is in the range of 12 to 14, y is in the range of 0.05 to 0.4, z is in the range of 1 to 2.5, a is in the range of 5 to 7, b1 is in the range of 0.2 to 0.6, b2 is in the range of 1 to 3, b3 is in the range of 0.1 to 1.0, d1 is in the range of 0.01 to 0.15, and d2 is in the range of 0.01 to 0.8.

15. The process of claim 1 , wherein the catalyst material has an attrition resistance of less than 0.6.

16. The process of claim 1 , wherein, of the crystalline content of the catalyst material, no more than 10% is Fe 2 (MoO 4 ) 3 .

17. A catalyst material prepared by the process according to claim 1 .

18. A process for the conversion of propylene, isobutylene, or a mixture thereof to acrylonitrile, methacrylonitrile, or a mixture thereof, the process comprising reacting the propylene, isobutylene, or the mixture thereof with ammonia and oxygen in the vapor phase in contact with a catalyst material according to claim 17 .

19. A process for the conversion of propylene, isobutylene, or a mixture thereof to acrolein, methacrolein, or a mixture thereof, the process comprising reacting the propylene, isobutylene, or the mixture thereof with oxygen in the vapor phase in contact with a catalyst material according to claim 17 .

20. The process of claim 1 , wherein

the solvent is an aqueous organic acid selected from glycolic acid, acetic acid, lactic acid and mixtures thereof, at a concentration in the range of 45-90 wt %; and

less than about 1 wt % of each of the molybdenum oxide precursor, the bismuth oxide precursor, and the iron oxide precursor is not dissolved in the solvent.

21. The process of claim 20 , wherein the inert carrier has an average particle size less than about 1 microns.