Catalytic Descriptors for the Design of Ziegler-Natta Catalysts Re-vealed by the Investigation of the Cl-Ti(0001) Interaction by Densi-ty of States Calculations

ABSTRACT: The deposition of MgCl2 on Ti(0001) followed by annealing above 450 oC has been previously reported to result in the desorption of the Mg atoms, the formation of a Cl/Ti(0001) interface and a new contribution at Binding Energy (BE) 3.5 eV. We present Density of States results from DFT calculations obtained for the Cl/Ti(0001) interface and compare them with reported spectra obtained by photoelectron spectroscopy with synchrotron radiation. Our results suggest that the new contribution at BE 3.5 eV is a Cl3p peak originating from Cl atoms relaxing at long dis-tances from the surface, whereas the Cl3p peak at BE 7.0 eV should be attributed only to Cl atoms strongly adsorbed at either one of the hollow sites of the Ti(0001) surface. Our calculations also support an interpretation for published ex-perimental observations on the valence band of TiCl4 adsorbed on a Au surface. The comparisons of DFT calculations with experimental results highlight significant features of the Ti-Cl interaction at dista...