Catalyst for producing n-substituted carbamates, and the preparation and application of the same

Abstract

The present invention relates to a novel catalyst for producing N-substituted carbamates, the preparation of the catalyst and an improved method for producing N-substituted carbamates from these novel catalysts. The active component of the catalyst is a heteropoly acid and the catalyst support comprises a metal oxide or a metalloid oxide. The catalyst can be used to promote the reaction of carbamate and amine, thereby generating N-substituted carbamates with high yield. In the presence of the catalyst, the reaction conditions are relatively mild, the catalytic activity and selectivity of the reaction are high, and the reaction time is relatively short. Furthermore, the catalyst can be conveniently separated from the reaction system and recycled, therefore, the catalyst can be used to facilitate the further scale-up test and commercial application.

1 - 12 . (canceled) 
     
     
         13 . A catalyst for preparing a N-substituted carbamate, wherein the active component of the catalyst comprises a heteropoly acid and the component of the catalyst support comprise a metal oxide or metalloid oxide. 
     
     
         14 . The catalyst of  claim 13 , wherein the heteropoly acid is a Keggin type heteropoly acid. 
     
     
         15 . The catalyst of  claim 14 , wherein the heteropoly acid is selected from the group consisting of H 3 PW 12 O 40 .nH 2 O, H 3 PMo 12 O 40 .nH 2 O, H 4 SiW 12 O 40 .nH 2 O and H 4 SiMo 12 O 40 .nH 2 O. 
     
     
         16 . The catalyst of  claim 13 , wherein the catalyst support component comprising a metal oxide or a metalloid oxide is selected from the group consisting of zirconium oxide, titanium oxide, zinc oxide, silicon oxide, magnesium oxide, calcium oxide, tin oxide, barium oxide, cerium oxide, lanthanum oxide, vanadium pentoxide, aluminium oxide and mixtures thereof. 
     
     
         17 . The catalyst of  claim 16 , wherein the metal oxide is selected from the group consisting of a vanadium pentoxide, an aluminium oxide and mixtures thereof. 
     
     
         18 . The catalyst of  claim 13 , wherein the load of the active component of the catalyst is from 0.1 to 20 wt. %, based on 100 wt. % of the catalyst support. 
     
     
         19 . A method for preparing the catalyst of  claim 13 , comprising
 (1) impregnating (i) a catalyst support into (ii) a heteropoly acid solution comprising one or more heteropoly acids to form a catalyst precursor, and   (2) calcinating said catalyst precursor at a temperature of from 150 to 1000° C. to obtain a catalyst.   
     
     
         20 . The method of  claim 19 , wherein said heteropoly acid is selected from the group consisting of H 3 PW 12 O 40 .nH 2 O, H 3 PMo 12 O 40 . nH 2 O, H 4 SiW 12 O 40 .nH 2 O and H 4 SiMo 12 O 40 .nH 2 O. 
     
     
         21 . The method of  claim 19 , wherein said metal oxide or said metalloid oxide is selected from the group consisting of zirconium oxide, titanium oxide, zinc oxide, silicon oxide, magnesium oxide, calcium oxide, tin oxide, barium oxide, cerium oxide, lanthanum oxide, vanadium pentoxide, aluminium oxide and mixtures thereof. 
     
     
         22 . The method of  claim 21 , wherein said metal oxide is selected from the group consisting of a vanadium pentoxide, an aluminium oxide and mixtures thereof. 
     
     
         23 . The method of  claim 19 , wherein the load of the active component of the catalyst is from 0.1 to 20 wt. %, based on 100 wt. % of the catalyst support. 
     
     
         24 . The method of  claim 19 , additionally comprising a drying step after (1) said impregnating step and before (2) said calcinating step, wherein the temperature of the drying step is less than or equal to 140° C.