Bimetallic catalysts with higher activity

Methods of preparing bimetallic catalysts are disclosed. The methods include the steps of providing a supported non-metallocene catalyst, contacting a slurry of the supported non-metallocene catalyst in a non-polar hydrocarbon with a solution of a metallocene compound and an alumoxane, and drying the contact product to obtain a supported bimetallic catalyst. The supported non-metallocene catalyst is prepared by dehydrating a particulate support material at a temperature of greater than 600° C., preparing a slurry of the dehydrated support in a non-polar hydrocarbon, contacting the slurry with an organomagnesium compound and an alcohol, contacting the resulting slurry with a non-metallocene compound of a Group 4 or Group 5 transition metal, and drying the contact product to obtain a supported non-metallocene catalyst as a free-flowing powder. The bimetallic catalysts show increased activity relative to catalysts prepared using support materials dehydrated at lower temperatures.