To combine a Ziegler–Natta catalyst and the metallocene ofrac-CH2(3-t-Bu-1-Ind)2ZrCl2to form a bimetallic catalyst with-out much changing their catalytic performances, it is essential tofind an intermediate that could react both with the Ziegler–Nattacatalyst and with the metallocene while does not significantlyalter their structures/compositions. In this context, MAO, with theinevitable trimethylaluminum (TMA) depleted as exhaustive as possible, may best serve this goal. MAO is an activator of met-allocene, which, with its oft-quoted cage structure, will complexwith the latter in its own capsule. Moreover, internal electrondonors such as phthalates and 1,3-diethers are known to haveacid-base complex interaction with alkylaluminums [23]. How-ever, conventional phthalates tend to be displaced from the catalystby this interaction. 1,3-diethers, on the other hand, show theunique property of virtually not being removed at all by alkyla-luminums. With the above knowledge in mind, we have rationallydesigned a way of incorporating rac-CH2(3-t-Bu-1-Ind)2ZrCl2intoZiegler–Natta catalyst forming a bimetallic “two-in-one” catalystthat, with a granular whole piece, contains two discrete catalystspecies, based on a spherical-shaped MgCl2/TiCl4catalyst bearing9,9-bis(methoxymethyl)fluorene (BMMF) internal electron donorand MAO-treated (protected) rac-CH2(3-t-Bu-1-Ind)2ZrCl2, as illus-trated in Scheme 1.The procedure to prepare the MgCl2/TiCl4/BMMF catalyst is typ-ical of a MgCl2/TiCl4supported catalyst preparation (see Section 2).This preparation gives a Ti content of 3.57 wt% and BMMF contentof 16.2 wt%, respectively, which are both in the normal ranges ofthose elements in a typical 1,3-diether-containing 4th generationZiegler–Natta catalyst [23]. Moreover, the catalyst exudes sphericalparticles of slightly porous architectures, as shown in Fig. 1. Treat-ing this precursory MgCl2/TiCl4/BMMF catalyst with a mixture ofrac-CH2(3-t-Bu-1-Ind)2ZrCl2and MAO gives rise to the adsorption