Methods of preparing a polymerization catalyst

A method comprising:

• thermally treating a silica support material consisting essentially of silica 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;
• thermally treating the precursor polymerization catalyst to form a polymerization catalyst;
• contacting a monomer with the polymerization catalyst under conditions suitable for the formation of a polymer;
• and
• recovering the polymer wherein the polymer has a weight average molecular weight that is decreased by from about 5% to about 99% when compared to the weight average molecular weight of a polymer obtained from an otherwise identical catalyst made in the absence of the sulfating agent.

A method comprising:

• contacting a silica support material consisting essentially of silica with a sulfating agent and a chromium-containing compound to form a mixture;
• thermally treating the mixture to form a polymerization catalyst;
• contacting a monomer with the polymerization catalyst under conditions suitable for the formation of a polymer;
• and
• recovering the polymer wherein the polymer has a weight average molecular weight that is decreased by from about 5% to about 99% when compared to the weight average molecular weight of a polymer obtained from an otherwise identical catalyst made in the absence of the sulfating agent.