A method of preparing a hydrolyzed pre-catalyst comprising: a) drying a silica support by heating the silica support to a temperature in a range of from about 150 °C to about 250 °C and maintaining the temperature of the silica support in the range of from about 150 °C to about 250 °C for a time period of from about 1 hour to about 24 hours to form a dried support; b) contacting the dried support and a titanium alkoxide to form a titanated support; c) drying the titanated support by heating the titanated support to a temperature in a range of from about 50 °C to about 200 °C and maintaining the temperature of the titanated support in the range of from about 50 °C to about 200 °C for a time period of from about 30 minutes to about 6 hours to form a dried titanated support; d) contacting the dried titanated support and an aqueous alkaline solution comprising from about 3 wt. % to about 20 wt. % of a nitrogen-containing compound for a time period of from about 10 minutes to about 6 hours to form a mixture comprising a hydrolyzed titanated support wherein a weight ratio of the amount of aqueous alkaline solution to the amount of titanium alkoxide in the dried titanated support is from about 30:1 to about 3:1; and e) removing the hydrolyzed titanated support from the mixture comprising the hydrolyzed titanated support and drying the hydrolyzed titanated support by heating the hydrolyzed titanated support to a temperature in a range of from about 50 °C to about 200 °C and maintaining the temperature of the hydrolyzed titanated support in the range of from about 50 °C to about 200 °C for a time period of from about 30 minutes to about 6 hours to form the hydrolyzed pre-catalyst. a) drying a silica support by heating the silica support to a temperature in a range of from about 150 °C to about 250 °C and maintaining the temperature of the silica support in the range of from about 150 °C to about 250 °C for a time period of from about 1 hour to about 24 hours to form a dried support; b) contacting the dried support and a titanium alkoxide to form a titanated support; c) drying the titanated support by heating the titanated support to a temperature in a range of from about 50 °C to about 200 °C and maintaining the temperature of the titanated support in the range of from about 50 °C to about 200 °C for a time period of from about 30 minutes to about 6 hours to form a dried titanated support; d) contacting the dried titanated support and an aqueous alkaline solution comprising from about 3 wt. % to about 20 wt. % of a nitrogen-containing compound for a time period of from about 10 minutes to about 6 hours to form a mixture comprising a hydrolyzed titanated support wherein a weight ratio of the amount of aqueous alkaline solution to the amount of titanium alkoxide in the dried titanated support is from about 30:1 to about 3:1; and e) removing the hydrolyzed titanated support from the mixture comprising the hydrolyzed titanated support and drying the hydrolyzed titanated support by heating the hydrolyzed titanated support to a temperature in a range of from about 50 °C to about 200 °C and maintaining the temperature of the hydrolyzed titanated support in the range of from about 50 °C to about 200 °C for a time period of from about 30 minutes to about 6 hours to form the hydrolyzed pre-catalyst.