Zeolite MCM-22 supported heterogeneous chromium catalyst for ethylene polymerization

• Published in: Catalysis letters Vol. 88; no. 3-4; pp. 227 - 229
• Main Authors: VARKEY, Saji P, LOBO, Raul F, THEOPOLD, Klaus H
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.06.2003; Springer Nature B.V
• Subjects: Applied sciences; Catalysis; Catalysts; Chromium; Composite materials; Ethylene; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polyethylenes; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Zeolites; Polyethylene; chromium; Complex catalyst polymerization; Zeolite; Complex catalyst; Experimental study; ethylene polymerization; Supported catalyst; MCM-22; Heterogeneous polymerization; Chromium Complexes; Olefin polymer; Catalyst activity
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1023/A:1024030326621

The chromium alkyl complex Cp*Cr(py)Me2 (Cp* = η5-pentamethylcyclopentadienyl, py = pyridine, Me = methyl) has been affixed to the surface of zeolite MCM-22 via methane elimination. The resulting composite material has been characterized by a variety of physical methods. The results are consistent with the presence of isolated organometallic fragments linked to the solid support by a covalent chromium–oxygen bond. Activation of this material with methylaluminoxane (MAO) yielded a highly active catalyst for the polymerization of ethylene. The polyethylene thus formed featured high molecular weights (Mw ∼ 4 × 106) and narrow molecular weight distributions (Mw/Mn ∼ 3.5).