Catalysts for the hydration of nitriles to amides

Abstract

Copper, copper oxide, copper-chromium oxide, copper-molybdenum oxide or mixtures thereof have been found to be excellent heterogeneous catalysts for the conversion of nitriles in the presence of water to the corresponding amides. Using one such catalyst in a continuous flow reactor, acrylonitrile was almost 100% converted to acrylamide during more than six weeks of continuous operation.

We claim: 
     
       1. In the process for converting a nitrile to the corresponding amide, the improvement comprising: reacting by contacting an .[.aliphatic nitrile.]. .Iadd.olefinic nitrile of 3 to 6 carbon atoms .Iaddend.in the presence of water with a heterogeneous, cupreous catalyst consisting essentially of copper prepared by reducing copper oxide, copper oxide, copper-chromium oxide, copper-molybdenum oxide or mixtures thereof. 
     
     
       2. The process of claim 1 wherein the catalyst is copper prepared by reducing copper oxide, copper oxide or copper-chromium oxide. 
     
     
       3. The process of claim 1 wherein the catalyst is essentially 10 to 90% by weight of copper oxide and 10 to 90% of chromium oxide or molybdenum oxide. 
     
     
       4. The process of claim 1 wherein the copper oxide, copper-chromium oxide or copper-molybdenum oxide catalyst is reduced by contact with a reducing agent prior to the conversion of the nitrile to the corresponding amide. 
     
     
       5. The process defined in claim 4 wherein the reducing agent is elemental hydrogen. 
     
     
       6. The process of claim 4 wherein the catalyst is reduced at a temperature of about 50° to about 500° C. 
     
     
       7. The process of claim 6 wherein the catalyst is reduced at a temperature of about 100° to about 300° C. 
     
     
       8. The process of claim 1 wherein at least 50% of the copper content of the catalyst is cuprous oxide. 
     
     
       9. The process of claim 1 wherein the copper content of the catalyst is essentially cuprous oxide containing a minor amount of copper metal. .[.10. The process of claim 1 wherein the nitrile is an aliphatic hydrocarbon nitrile of up to 20 carbon atoms..]. .[.11. The process of claim 10 wherein the nitrile is an olefinic nitrile of 3 to 6 carbon 
     
     
        atoms..]. 12. The process of claim .[.11.]. .Iadd.1 .Iaddend.wherein the 
     
     
        nitrile is acrylonitrile. 13. The process of claim 1 wherein the 
     
     
        temperature is about 0° to about 400° C. 14. The process of claim 13 wherein the temperature is about 25° to about 200° 
     
     
        C. 15. The process of claim 1 wherein the reaction is run in the liquid 
     
     
        phase. 16. In the process for converting a nitrile to the corresponding amide by contacting .[.the nitrile.]. .Iadd.an olefinic nitrile of 3 to 6 carbon atoms .Iaddend.in the presence of water with a heterogeneous catalyst, the improvement comprising using a cupreous catalyst consisting essentially of reduced copper oxide, reduced copper-chromium oxide, reduced copper-molybdenum oxide, unreduced copper-molybdenum oxide or 
     
     
        mixtures thereof. 17. The process of claim 16 wherein the catalyst is 
     
     
        reduced copper oxide or reduced copper-chromium oxide. 18. The process of claim 17 wherein the catalyst is a reduced copper-chromium oxide which contained 10 to 90% copper oxide and 10 to 90% chromium oxide before 
     
     
        reduction. 19. The process of claim 17 wherein the catalyst was reduced by 
     
     
        elemental hydrogen. 20. The process of claim 17 wherein the catalyst was 
     
     
        reduced at a temperature of about 50° to about 500° C. 21. The process of claim 17 wherein the catalyst was reduced at a 
     
     
        temperature of about 100° to about 300° C. 22. The process of claim 17 wherein at least 50% of the copper content of the catalyst is 
     
     
        cuprous oxide. 23. The process of claim 17 wherein the copper content of the catalyst is cuprous oxide containing a minor amount of copper metal. .[.24. The process of claim 16 wherein the nitrile is an aliphatic or aromatic hydrocarbon nitrile of up to about 20 carbon atoms..]. .[.25. The process of claim 24 wherein the nitrile is an olefinic nitrile of 3 to 6 
     
     
        carbon atoms..]. 26. The process of claim .[.25.]. .Iadd.16 
     
     
        .Iaddend.wherein the nitrile is acrylonitrile. 27. The process of claim 16 
     
     
        wherein the temperature is about 0° to about 400° C. 28. The process of claim 27 wherein the temperature is about 25° to about 
     
     
        200° C. 29. The process of claim 16 wherein the reaction is conducted in the liquid phase.