Embodiments of the present disclosure directed towards polymerization catalysts having improved ethylene enchainment. As an example, the present disclosure provides a polymerization catalyst having improved ethylene enchainment, the polymerization catalyst comprising a zirconocene catalyst of Formula (I) where R1 is a C1 to C20 alkyl, aryl or aralkyl group, wherein R2 is an C1 to C20 alkyl, aryl or aralkyl group, and where R3 is a C1 to C20 alkyl or a hydrogen, and where each X is independently a halide, C1 to C20 alkyl, aralkyl group or hydrogen.