Olefin metathesis catalyst containing tungsten fluorine bonds

Abstract

A catalyst for the metathesis of olefins in general and specifically for the production of propylene from ethylene and butylene has been developed. The catalyst comprises a tungsten metal compound, which contains at least one tungsten-fluoro bond, dispersed or grafted onto a support. A specific example of the catalyst is the compound WOF(CH 2 CMe 3 ) 3 grafted onto a silica support.

1 . A process for preparing a catalyst for the metathesis of olefins comprising a tungsten metal compound characterized in that it contains at least one tungsten-fluorine bond, the compound dispersed on a refractory oxide support wherein the compound is chemically bonded to the support; the process comprising contacting the tungsten metal compound with the support by a method selected from the group consisting of: 1) contacting the support with a solution of the compound at solution contacting conditions; 2) subliming the tungsten metal compound onto the support at sublimation conditions and 3) directly contacting the tungsten metal compound with the support at direct contacting conditions. 
     
     
         2 . The process of  claim 1  where the method of preparation comprises contacting a solution of a tungsten metal compound with a refractory oxide support at a temperature of about −100° to about 80° C., for a time of about 5 minutes to about 24 hours and recovering the resultant catalyst. 
     
     
         3 . The process of  claim 1  where the method of preparation comprises contacting a solution of a tungsten metal compound with a refractory oxide support at a temperature of about −75° to about 35° C., for a time of about 5 minutes to about 24 hours and recovering the resultant catalyst. 
     
     
         4 . The process of  claim 1  where the solution comprises from about 0.5 to about 25 wt-% W as the metal. 
     
     
         5 . The process of  claim 1  where the method of preparation comprises sublimation and sublimation conditions comprise subliming the tungsten metal compound onto the support under vacuum at a temperature of about 30° to about 150° C. for a time of about 1 to about 4 hours. 
     
     
         6 . The process of  claim 5  where any excess tungsten metal compound is removed from the catalyst by reverse sublimation at a temperature of about 30° to about 150° C. and condensed. 
     
     
         7 . The process of  claim 1  where the method of preparation is direct contact and direct contact conditions comprise stirring a mixture of the tungsten metal compound with the support at a temperature of about -10° to about 100° C. for a time of about 2 to about 6 hours under an inert atmosphere. 
     
     
         8 . The process of  claim 1  where the tungsten containing compound is selected from the group consisting of a WR 4 F, WOFR 3  or W(NR′)FR 3  and mixtures thereof where R is an organic group which does not have any hydrogen atoms beta to the tungsten and R′ is selected from the group consisting of H, phenyl, 2,6-dimethylphenyl and methyl. 
     
     
         9 . The process of  claim 7  where R is selected from the group consisting of neopentyl (—CH 2 CMe 3 ); methyl, 2,2-diethylpropyl (—CH 2 C(CH 2 CH 3 ) 2 Me), and 2,2-diethylbutyl (—CH 2 C(CH 2 CH 3 ) 2 CH 2 CH 3 ).