US Patent 9068027 Methods of preparing a polymerization catalyst

A method comprising contacting a silica support material with a sulfating agent to form a sulfated silica support material comprising sulfate anions; thermally treating the sulfated silica support material to form a thermally treated sulfated silica support material; contacting the thermally treated sulfated silica support material with a chromium-containing compound to form a mixture; and thermally treating the mixture to form a polymerization catalyst. A method comprising thermally treating a silica support material to form a thermally-treated silica support material; contacting the thermally-treated silica support material with a sulfating agent to form a thermally treated sulfated silica support material; thermally treating the thermally treated sulfated silica support material to form a processed silica support material; contacting the processed silica support material with a chromium-containing compound to form a precursor polymerization catalyst; and thermally treating the precursor polymerization catalyst to form a polymerization catalyst.