M. Boero et al., A first principles exploration of a variety of active surfaces and catalytic sites in Ziegler-Natta heterogeneous catalysis, J PHYS CH A, 105(21), 2001, pp. 5096-5105
We present a Car-Parrinello investigation of various active surfaces and ca
talytic sites in a realistic Ziegler-Natta heterogeneous system. We examine
the (100), (110), and (104) surfaces of the MgCl2 support and the related
binding of the possible mononuclear and dinuclear catalyst configurations.
Relaxation and/or reconstruction processes affect these surfaces in varying
degrees, according to the different Miller indexes. We find that TiCl4 and
Ti2Cl6 species can bind as stable adducts, depending on the morphology of
the surface considered. However, the activation and polymerization phases s
how that destabilization phenomena can affect the dinuclear species during
the catalysis reaction. This provides a new insight into the ability of the
different centers to give rise to the real polymerization process. Finally
, we present a first attempt to address the role of a typical donor phthala
te at a fully first principles level.