Silica-supported zirconocene catalysts: Preparation, characterization and activity in ethylene polymerization

Improving the Performance of Heterogeneous Borane Cocatalysts by Pretreatment of the Silica Support with Alkylaluminum Compounds

“…Alkylaluminum is known to react with accessible OH groups of silica at room temperature to form surface Si1O1AlR 2 groups and evolve alkane, RH. [11,12] Figure 1c is the spectrum of untreated cocatalyst [CPh 3 ] + [B(C 6 F 5 ) 3 1SiO 2 ] -(1). The reduced intensity of the 3 658 cm -1 single hydroxyl peak shows that B(C 6 F 5 ) 3 is also interacting with the single hydroxyl groups of silica.…”

“…Therefore alkylaluminum compounds, which are scavengers for impurities, were used to modify the supports before preparing the supported cocatalyst system. [11] In order to improve the catalytic performance. The present work reports the preparation of supported borane cocatalyst systems by treating the silica support with the alkylaluminums TIBA, TEA and trimethylaluminium (TMA) before functionalizing the silica support with B(C 6 F 5 ) 3 and then stabilizing the resulting complex with CPh 3 Cl as shown in Scheme 2.…”

Preparation and characterization of agglomerated porous hollow silica supports for olefin polymerization catalyst

“…At present, most attentions have been paid to the use of supported metallocene complexes [4][5][6][7][8]. Many different materials such as SiO 2 , MgCl 2 , MCM-41, zeolite, carbon, SiO 2 / MgCl 2 and polymer have been used as support for metallocene catalysts in olefin polymerization [9][10][11][12][13][14][15][16][17].…”

Modified silicas as supports for single-site zirconocene catalysts

“…Such systems were shown to be active in the presence of common trialkylaluminium cocatalysts. Moroz et al [4] prepared a supported metallocene catalyst by treating a silylated silica, obtained by the reaction of dehydroxylated silica with ClSiMe 3 , with Cp 2 ZrCl 2 . The resulting material had a zirconium content of 0.1% and, in combination with MAO, was found to be an active catalyst for ethylene polymerization (55 KgPE molZr −1 h −1 bar −1 , Al/Zr = 100).…”