Computer-modelling studies on MgCl2-supported Ziegler–Natta catalysts

Abstract

Computer-modelling techniques based on a Born-model representation of the polar solid and a shell-model description of ionic polarizability have been used to simulate the bulk and surface structures of the β-MgCl₂ crystal. Mott–Littleton techniques have been applied to the study of the energetics of solution of TiCl₂, TiCl₃ and TiCl₄ into the bulk and onto the surfaces of the material. We also investigate the structures and energetics of adsorbed TiCl₂, TiCl₃ and TiCl₄ complexes at different surfaces and demonstrate the possible active sites of MgCl₂ supported catalysts. Finally, we calculate the activation energies for the surface diffusion of TiCl₄ and the surface dissociation energies of TiCl₄ and TiCl₃ with dissociation of Cl^–.