Ethylene polymerization with metallocene and trimethylaluminumtreated silica

To prepare supported catalyst for ethylene polymerization, silica was treated with trialkylaluminum (AIR3) followed by supporting Cp2ZrCl2. Partially hydrated silica (H‐SiO2) was chosen for reaction with AIR3 to prepare catalyst precursor. The H‐SiO2/ AIR3 / Metallocene catalyst system could effectively catalyse ethylene polymerization even with common alkylaluminums as cocatalyst. The catalytic activity of supported catalyst depended on H2O content of silica. H2O/(CH3) 3Al ratio, metallocene and cocatalyst. The analysis data of silica surface by BET and CP MAS 13C NMR revealed that the catalyst precursor prepared from the reaction between H‐SiO2 and (CH3) 3Al was methylaluminoxane (PMAO) supported on silica with high surface area and reduced pore size.