Formation of zirconium hydrides in supported organozirconium catalysts and their role in ethylene polymerization

Abstract On the basis of the IR-study of polymerization catalysts obtained by the interaction of tetrakis-π-allylzirconium with silica it has been concluded that when treating these catalysts with hydrogen, surface zirconium hydrides are formed. These hydride compounds are direct precursors of the propaga- tion centres for ethylene polymerization.