Structure Determination of the δ-MgCl<sub>2</sub> Support in Ziegler-Natta Catalysts

δ-MgCl2 support is an essential component of highly active Ziegler-Natta catalysts. The microstructure of δ-MgCl2 in modern industrial catalysts is extremely disordered, so is hard to determine using only powder X-ray diffraction (PXRD). Several structural models have been proposed, such as nano-sized platelet crystallites and one-dimensional chain-like structures. We used atomic pair distribution function (PDF) based on total X-ray scattering and simulations with nanoparticle models in addition to PXRD to investigate the detailed structure of δ-MgCl2. We found that δ-MgCl2 in modern catalysts consists of nano-sized platelet crystallites with stacking disorder, regardless of the preparation protocol. Here, we review our recent findings of the structure determination of δ-MgCl2.