Unraveling the Catalytic Synergy between Ti3+ and Al3+ Sites on a Chlorinated Al2O3: A Tandem Approach to Branched Polyethylene
| Autor: | Alessandro Piovano, K. S. Thushara, Mario Chiesa, Elena Groppo, Elena Morra |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Ethylene
Tandem 010405 organic chemistry operando FT-IR spectroscopy Chemistry (all) tandem catalysis General Chemistry General Medicine Polyethylene Heterogeneous catalysis 010402 general chemistry 01 natural sciences Ti3+ sites Catalysis 0104 chemical sciences chemistry.chemical_compound chemistry Polymer chemistry Coordination polymerization Ziegler–Natta catalysts Lewis acids and bases EPR spectroscopy Bifunctional |
| Popis: | An original step-by-step approach to synthesize and characterize a bifunctional heterogeneous catalyst consisting of isolated Ti(3+) centers and strong Lewis acid Al(3+) sites on the surface of a chlorinated alumina has been devised. A wide range of physicochemical and spectroscopic techniques were employed to demonstrate that the two sites, in close proximity, act in a concerted fashion to synergistically boost the conversion of ethylene into branched polyethylene, using ethylene as the only feed and without any activator. The coordinatively unsaturated Al(3+) ions promote ethylene oligomerization through a carbocationic mechanism and activate the Ti(3+) sites for the traditional ethylene coordination polymerization. |
| Databáze: | OpenAIRE |
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