This proposal is concerned with determining the active species of the polymerisation catalyst comprising ansa-bridged indenyl zirconium complexes supported with MAO on silica and Layered Double Hydroxides (LDHs). This in-depth analysis of the supported catalyst is a challenge but is required to deepen our understanding of the polymerisation process. The results from this proposal are predicted to be interesting, not only at an academic level, but also to the industrial users of this technology.