摘要 |
An improved chromium oxide-based catalyst supported on a granular or microspherical refractory oxide for the gas phase polymerization of at least one alpha olefin containing from 2 to 12 carbon atoms, wherein the supported chromium oxide-based catalyst has been subjected to a sole calcination/activation step consisting of a single thermal treatment performed at a temperature ranging from 200° to 450° C. under an oxygen containing atmosphere, and an olefin polymerization process employing such catalyst. |