Process for Preparing Catalysts and Catalysts Made Thereby

Abstract

A process for preparing a catalyst comprising (A) selecting a catalyst support selected from the group consisting of gels of silica, silica alumina, alumina, aluminum phosphate, aluminaphospate, and combinations of two or more thereof; (B) mixing the catalyst support with one or more chromium containing compound, wherein the chromium containing compound is selected from the group consisting of chromium containing compounds which are oxidizable to a Cr +6 state and chromium containing compounds wherein the chromium is in a Cr +6 state; (C) mixing the catalyst support with one or more transition metal catalyst component; (D) calcining the catalyst support; and (E) optionally for the chromium containing compound which is oxidizable to a Cr +6 state, converting the chromium in the chromium containing compound to Cr +6 ; and (F) spray drying the catalyst support to form catalyst particles; wherein steps (B)-(F) may occur separately in any order or wherein any one or more of steps (B)-(F) may be combined together; and wherein the catalyst support gels are characterized by a surface area greater than 50 m 2 /gram and a pore volume greater than 0.5 cc/gram at the time of mixing the catalyst support gels with the chromium containing compound is provided.

1 .- 16 . (canceled) 
     
     
         17 . A catalyst produced according to a process comprising:
 (A) selecting a catalyst support selected from the group consisting of gels of silica, silica alumina, alumina, aluminum phosphate, aluminaphosphate, and combinations of two or more thereof;   (B) mixing the catalyst support with one or more chromium containing compound, wherein the chromium containing compound is selected from the group consisting of chromium containing compounds which are oxidizable to a Cr +6  state and chromium containing compounds wherein the chromium is in a Cr +6  state;   (C) mixing the catalyst support with one or more transition metal catalyst component;   (D) calcining the catalyst support while continuously agitating to prevent agglomeration;   (E) optionally for the chromium containing compound which is oxidizable to a Cr +6  state, converting the chromium in the chromium containing compound to Cr +6 ; and   (F) spray drying the catalyst support to form catalyst particles;   wherein steps (B)-(F) may occur separately in any order or wherein any one or more of steps (B)-(F) may be combined together; and   wherein the catalyst support gels are characterized by a surface area greater than 50 m 2 /gram and a pore volume greater than 0.5 cc/gram at the time of mixing the catalyst support gels with the chromium containing compound.   
     
     
         18 . The catalyst according to  claim 17 , wherein steps (B) and (D) are conducted sequentially. 
     
     
         19 . The catalyst according to  claim 17 , wherein step (B) occurs prior to steps (C)-(F) and steps (D) and (E) occur simultaneously. 
     
     
         20 . The catalyst according to  claim 17 , wherein the catalyst support selected in step (A) comprises gels larger than 50 micron characterized by a surface area greater than 50 m 2 /gram and a pore volume greater than 0.5 cc/gram, and wherein step (D) occurs following step (A) and is followed by comminution of the catalyst support gels to form gels characterized by a surface area greater than 50 m 2 /gram and a pore volume greater than 0.5 cc/gram prior to step (B) and an average particle size less than 15 micron. 
     
     
         21 . The catalyst according to  claim 17 , wherein steps (A), (B) and (D) occur in order to form a chromium compound impregnated, calcined catalyst support gels, and further comprising suspension of the chromium compound impregnated, calcined catalyst support gels in a solvent containing a binder to form a suspension. 
     
     
         22 . The catalyst according to  claim 21 , wherein the binder is selected from the group consisting of methylalumoxane, polystyrene, polystyrene-ethylene copolymers, polysytrene allyl alcohol copolymers, polyvinylchloride, polyisoprene, polybutadiene, partially hydrogenated polyisoprene, modified methylalumoxane, polyvinylacetate, isobutylalumoxane, and trialkylaluminum compounds having the formula AlR 3  where R is a saturated alkyl group having more than 12 carbons and is soluble in aromatic solvents. 
     
     
         23 . The catalyst according to  claim 17 , wherein the chromium containing compound is selected from bis(triarylsilyl)chromates, and compounds characterized by the formula R b   2 Cr where R b  is a substituted or unsubstituted indenyl or cyclopentadienyl and wherein the two R b  may be the same or different. 
     
     
         24 . The catalyst according to  claim 17 , wherein the chromium containing compound is selected from the group consisting of chromium containing compounds having a Cr+3 state which are water and/or alcohol soluble. 
     
     
         25 . The catalyst according to  claim 17 , wherein the chromium containing compound is characterized by the formula Cr(NO 3 ) 3  and/or the formula Cr(CO 2 ) 3 . 
     
     
         26 . The catalyst according to  claim 17 , wherein the chromium containing compound is bis(triphenylsilyl)chromate. 
     
     
         27 . The catalyst according to  claim 17 , wherein the chromium containing compound is selected from the group consisting of bis-cyclopentadienylchromium, bis-indenylchromium, bis-pentamethycyclopentadienylchromium, and combinations of two or more thereof. 
     
     
         28 . The catalyst according to  claim 17 , wherein step (F) results in particles having a particle size of greater than 5 microns. 
     
     
         29 . The catalyst according to  claim 28 , wherein the resulting particles have a (volume or weight average) particle size of from 10 to 75 microns. 
     
     
         30 . The catalyst according to  claim 28 , wherein the resulting particles have a (volume or weight average) particle size of from 5 to 59 microns.