Patent ID: 7951881

Claim:
A method comprising: (a) providing a catalyst comprising chromium and a support having a pore volume of from about 1.7 ml/g to about 3.5 ml/g and a surface area of from about 450 m 2 /g to about 700 m 2 /g; (b) oxidizing the catalyst at a temperature of from about 500° C. to about 900° C. for a period of time of from about 1 hour to about 12 hours in an oxidizing atmosphere comprising from about 5 mol. % to about 100 mol. % oxygen to form an oxidized catalyst; (c) reducing the oxidized catalyst at a temperature of from about 700° C. to about 900° C. for a period of time of from about 1 hour to about 12 hours in a reducing atmosphere comprising from about 5 mol. % to abut 100 mol. % carbon dioxide to form an oxidized reduced catalyst; (d) oxidizing the oxidized reduced catalyst at a temperature of from about 500° C. to about 900° C. for a period of time of from about 1 hour to about 10 hours in an oxidizing atmosphere comprising from about 5 mol. % to about 100 mol. % oxygen to form an activated catalyst; (e) contacting the activated catalyst with an olefin under conditions suitable to form a polyolefin; and (f) recovering the polyolefin, wherein the polyolefin has a density of greater than about 0.960 g/cc and a melt index of from about 1.3 g/10 min. to about 2.8 g/10 min.