A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.