Process for production of adipic acid from 1,6-hexanediol

1. A process for preparing an adipic acid product, the process comprising chemocatalytically converting 1,6-hexanediol to the adipic acid product by a method comprising reacting the 1,6-hexanediol with oxygen in the presence of a heterogenous catalyst comprising gold and platinum on a support, wherein the support is selected from the group consisting of silica, carbon, zirconia, titania, metal oxide-composite and mixtures thereof.

2. A process for preparing an adipic acid product, the process comprising reacting 1,6-hexanediol and oxygen in the presence of a heterogeneous catalyst comprising gold on a support, wherein the support is selected from the group consisting of silica, carbon, zirconia, titania, alumina, metal oxide-composite and mixtures thereof, and wherein the weight percent of gold to the total weight of the finished catalyst is from about 0.1 wt % to about 10 wt %.

3. The process of claim 1 , wherein the heterogeneous catalyst comprises a support, the outer surfaces of the support comprising a material selected from the group consisting of zirconia, stabilized zirconia, zirconia-metal or -metal oxide composites, titania, stabilized titania, titania-metal or -metal oxide composites, silica and mixtures thereof.

4. The process of claim 2 , wherein the surface area of the support is equal to or less than about 220 m 2 /g and the average pore diameter is at least about 5 nm.

5. The process of claim 3 , wherein the support is a zirconia or stabilized zirconia support and further comprises tungsten.

6. The process of claim 1 , wherein the heterogeneous catalyst comprises a support selected from the group consisting of zirconia, stabilized zirconia, stabilized zirconia-metal or zirconia-metal oxide composite, titania, stabilized titania, stabilized titania-metal or titania-metal oxide composite, and mixtures thereof.

7. The process of claim 5 , wherein the tungsten is present in an amount ranging from about 1 wt % to about 15 wt % of the total weight of the support.

8. The process of claim 6 , wherein the support has a surface area equal to or less than about 220 m 2 /g and an average pore diameter of at least about 5 nm.

9. The process of claim 6 , wherein the support has a surface area equal to or less than about 100 m 2 /g and an average pore diameter of at least about 10 nm.

10. The process of claim 1 , wherein reacting the 1,6-hexanediol with oxygen in the presence of the heterogeneous catalyst comprises:

a) combining the 1,6-hexanediol and the heterogeneous catalyst, and optionally a solvent; and

b) contacting the combined 1,6-hexanediol and heterogeneous catalyst, and optionally the solvent, with oxygen.

11. The process of claim 1 , wherein reacting the 1,6-hexanediol with oxygen in the presence of the heterogeneous catalyst and, optionally a solvent comprises:

a) combining the 1,6-hexanediol and the heterogeneous catalyst, and optionally a solvent, at a temperature equal to or less than about 120° C. ; and

b) contacting with oxygen the combined 1,6-hexanediol and heterogeneous catalyst, and optionally the solvent.

12. The process of claim 1 , wherein reacting the 1,6-hexanediol with oxygen in the presence of the heterogeneous catalyst comprises:

a) combining the 1,6-hexanediol and a solvent;

b) contacting the combined 1,6-hexanediol and solvent with a heterogeneous catalyst; and

c) contacting the combined 1,6-hexanediol, solvent, and heterogeneous catalyst with oxygen.

13. The process of claim 11 , wherein the solvent is selected from the group consisting of water, alcohols, ethers, and mixtures thereof.

14. The process of claim 1 , wherein reacting the 1,6-hexanediol with oxygen in the presence of the heterogeneous catalyst and water comprises:

a) contacting the 1,6-hexanediol with water;

b) contacting the 1,6-hexanediol and water with the heterogeneous catalyst; and,

c) contacting the combined 1,6-hexanediol, water, and heterogeneous catalyst with oxygen.

15. The process of claim 3 , wherein the reaction is conducted under a partial pressure of oxygen ranging from about 50 psi to about 2000 psi.

16. The process of claim 3 , wherein the partial pressure of oxygen ranges from about 50 psig to about 1000 psig.

17. The process of claim 1 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature ranging from about 100° C. to about 180° C.

18. The process of claim 4 , wherein the reacting the 1,6-hexanediol with oxygen in the presence of a heterogeneous catalyst is carried out at a temperature ranging from about 135° C. to about 165° C.

19. The process of claim 1 , wherein the catalyst further comprises palladium.

20. The process of claim 1 , wherein the ratio of platinum to gold is from about 10:1 to about 1:1.

21. The process of claim 1 , wherein the total weight percent of platinum and gold is from about 0.2 wt % to about 5 wt % of the total weight of the catalyst.

22. The process of claim 1 , wherein the total weight percent of platinum and gold is equal to or less than about 4 wt % of the total weight of the catalyst.

23. The process of claim 2 , wherein the total weight percent of gold is from about 0.2 wt % to about 5 wt % of the total weight of the catalyst.

24. The process of claim 2 , wherein the total weight percent of gold is equal to or less than about 4 wt % of the total weight of the catalyst.

25. The process of claim 1 , wherein the support is selected from the group consisting of silica, carbon and zirconia.

26. The process of claim 2 , wherein the support is selected from the group consisting of silica, carbon and zirconia.

27. The process of claim 11 , wherein the solvent is water.