Microporous catalyst and method for hydrogenating aromatic compounds

Abstract

The invention relates to the hydrogenation of aromatic compounds, in particular the preparation of alicyclic polycarboxylic acids or their esters by core hydrogenation of the corresponding aromatic polycarboxylic acids or their esters, and also to catalysts suitable therefor.

1 . A catalyst comprising at least one metal of the eighth transition group of the Periodic Table on or in a support material, wherein 
 the support material comprises titanium dioxide which may further comprise an alkali metal, an alkaline earth metal and/or sulfur, and has an average pore diameter of from 2 to 50 nm and over 95% of the total pore volume of the support material is accounted for by pores having a diameter of less than 50 nm.    
     
     
         2 . The catalyst as claimed in  claim 1 , wherein 
 the specific surface area of the support material is between 1 and 350 m 2 /g.    
     
     
         3 . The catalyst as claimed in  claim 1 , wherein 
 the support material consists of titanium dioxide having a content of from 1.0 to 5.5% by mass of free sulfate.    
     
     
         4 . The catalyst as claimed in  claim 1 , wherein 
 the support material consists of titanium dioxide having a content of from 1.0 to 4.0% by mass of barium.    
     
     
         5 . The catalyst as claimed in  claim 1 , wherein 
 the catalyst additionally comprises at least one metal of the first transition group of the Periodic Table.    
     
     
         6 . The catalyst as claimed in  claim 1 , wherein 
 the catalyst further comprises at least one metal of the seventh transition group of the Periodic Table.    
     
     
         7 . A process for catalytically hydrogenating an aromatic polycarboxylic and/or monocarboxylic acid compound or a derivative thereof to the corresponding alicyclic compound comprising hydrogenating said aromatic polycarboxylic and/or monocarboxylic acid compound with a hydrogen-containing gas over a catalyst which comprises at least one metal of the eighth transition group of the Periodic Table on or in a support material, wherein 
 the support material comprises titanium dioxide which may further comprise an alkali metal, an alkaline earth metal and/or sulfur, and has an average pore diameter of from 2 to 50 nm and over 95% of the total pore volume of the support materials is accounted for by pores having a diameter of less than 50 nm.    
     
     
         8 . The process as claimed in  claim 7 , wherein 
 the specific surface area of the support material is between 1 and 350 m 2 /g.    
     
     
         9 . The process as claimed in  claim 7 , wherein 
 the support material consists of titanium dioxide having a content of from 1.0 to 5.5% by mass of free sulfate.    
     
     
         10 . The process as claimed in  claim 7 , wherein 
 the support material consists of titanium dioxide having a content of from 1.0 to 4.0% by mass of barium.    
     
     
         11 . The process as claimed in  claim 7 , wherein 
 the catalyst further comprises at least one metal of the first transition group of the Periodic Table.    
     
     
         12 . The process as claimed in  claim 7 , wherein 
 the catalyst further comprises at least one metal of the seventh transition group of the Periodic Table.    
     
     
         13 . The process as claimed in  claim 7 , wherein 
 said aromatic polycarboxylic and/or monocarboxylic acid compound or said derivative thereof is a carboxylic acid of benzene, diphenyl, naphthalene, diphenyl oxide or anthracene, its anhydride and/or a corresponding ester.    
     
     
         14 . The process as claimed in  claim 13 , wherein 
 the alcohol component of the carboxylic ester is alkoxyalkyl, cycloalkyl and/or an alkyl group having from 1 to 25 carbon atoms, branched or unbranched, each the same or different.    
     
     
         15 . A hydrogenation process comprising hydrogenating a compound with the catalyst as claimed in  claim 1 .  
     
     
         16 . A hydrogenation process as claimed in  claim 15  wherein said compound is an aromatic polycarboxylic and/or monocarboxylic acid or a derivative thereof.  
     
     
         17 . A hydrogenation process as claimed in  claim 16  wherein said aromatic polycarboxylic and/or monocarboxylic acid or derivative thereof is hydrogenated to the corresponding alicylic compounds.