Hierarchical aluminophosphates as catalysts for the beckmann rearrangement

Abstract

Methods for producing lactams from oximes by performing a Beckmann rearrangement using a hierarchical porous aluminophosphate catalyst having interconnected microporous and mesoporous networks are provided. Exemplary catalysts include a plurality of weak Brønsted acid active sites, including silicon-containing aluminophosphates having the IZA framework code AFI, such as SAPO-5, CHA, such as SAPO-34, and FAU, such as SAPO-37.

What is claimed is: 
     
         1 . A method of performing a Beckmann rearrangement reaction comprising the step of:
 reacting an oxime in the presence of a catalyst to produce a lactam, said catalyst comprising a hierarchical porous aluminophosphate comprising a microporous framework and a mesoporous framework.   
     
     
         2 . The method of  claim 1 , wherein the mesoporous framework has a pore diameter from 15 Å to 50 Å. 
     
     
         3 . The method of  claim 2 , wherein the microporous framework has a pore diameter from 3 Å to 10 Å. 
     
     
         4 . The method of  claim 1 , wherein the catalyst is a hierarchical porous aluminophosphate catalyst isomorphously substituted with one or two metals selected from the group consisting of: manganese, iron, copper, magnesium, chromium, cobalt, copper, zinc, silicon, titanium, vanadium, and tin. 
     
     
         5 . The method of  claim 1 , wherein the catalyst is a hierarchical porous aluminophosphate catalyst isomorphously substituted with one or two metals selected from the group consisting of: cobalt, silicon, and titanium. 
     
     
         6 . The method of  claim 1 , wherein the catalyst is a hierarchical porous silicoaluminophosphate catalyst selected from the group consisting of: HP SAPO-5, HP SAPO-11, HP SAPO-18, HP SAPO-31, HP SAPO-34, HP SAPO-37, HP SAPO-41, and HP SAPO-44. 
     
     
         7 . The method of  claim 6 , wherein the catalyst is selected from HP SAPO-5, HP SAPO-34, and HP SAPO-37. 
     
     
         8 . The method of  claim 1 , wherein the catalyst is a hierarchical catalyst comprising a microporous structure having an IZA framework code selected from the group consisting of: AFI, CHA, and FAU. 
     
     
         9 . The method of  claim 1 , wherein the catalyst is a hierarchical porous aluminophosphate catalyst isomorphously substituted with one or two metals selected from the group consisting of: cobalt and titanium. 
     
     
         10 . The method of  claim 9 , wherein the catalyst is selected from the group consisting of HP Co AlPO-5, HP Ti AlPO-5, and HP Co Ti AlPO-5. 
     
     
         11 . The method of  claim 1 , wherein the oxime is selected from cyclohexanone oxime, cyclooctanone oxime, and cyclododecanone oxime. 
     
     
         12 . The method of  claim 1 , wherein said reacting is performed in the gas phase. 
     
     
         13 . The method of  claim 1 , wherein said reacting is performed in the liquid phase. 
     
     
         14 . A hierarchical porous catalyst comprising:
 an aluminophosphate framework with an IZA framework code selected from the group consisting of AFI, CHA, and FAU;   a plurality of interconnected micropores, each micropore having a pore diameter from 3 to 10 Å; and   a plurality of mesopores interconnected with the micropores, each mesopores having a pore diameter from 15 Å to 50 Å.   
     
     
         15 . The hierarchical porous catalyst of  claim 14 , wherein the catalyst is a hierarchical porous aluminophosphate catalyst isomorphously substituted with one or two metals selected from the group consisting of: cobalt, silicon, and titanium 
     
     
         16 . The hierarchical porous catalyst of  claim 14 , wherein the catalyst is a hierarchical porous silicoaluminophosphate catalyst selected from the group consisting of: HP SAPO-5, HP SAPO-34, and HP SAPO-37. 
     
     
         17 . The hierarchical porous catalyst of  claim 14 , wherein the catalyst is a hierarchical porous aluminophosphate catalyst isomorphously substituted with one or two metals selected from the group consisting of: cobalt and titanium. 
     
     
         18 . The hierarchical porous catalyst of  claim 17 , wherein the catalyst is selected from the group consisting of HP Co AlPO-5, HP Ti AlPO-5, and HP Co Ti AlPO-5. 
     
     
         19 . The hierarchical porous catalyst of  claim 14 , wherein the hierarchical porous catalyst is phase pure. 
     
     
         20 . The hierarchical porous catalyst of  claim 14 , further comprising a plurality of weak Brønsted acid active sites.