High catalytic activity of SBA-15-supported metallocene toward ethylene polymerization: The effect of the ordered porous structure of the support
The catalytic activity of the (nBuCp)2ZrCl2 metallocene supported on ordered SBA-15 mesoporous silica and on traditional amorphous silica toward the polymerization of ethylene is studied. High activity values were obtained with the SBA-15-supported catalyst (6953–8407 kg mol−1 Zr bar−1 h−1), which were significantly higher than those presented by the catalyst supported on amorphous silica (959–4234 kg mol−1 Zr bar−1 h−1). The highly ordered mesoporous structure of SBA-15 affords a more homogeneous distribution of the metallocene on the support surface and improves accessibility during metallocene activation and monomer insertion. Polyethylene (PE) synthesized with the SBA-15-supported catalyst retains the molecular weight distribution of the PE produced with the single-site homogeneous metallocene, making the SBA-15-supported catalyst a promising heterogeneous metallocene system.
Journal: Catalysis Communications - Volume 10, Issue 6, 15 February 2009, Pages 995–1001