Toward a Unified Model Explaining Heterogeneous Ziegler鈥揘atta Catalysis

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• 作者：Raffaele Credendino ; Dario Liguori ; Zhiqiang Fan ; Giampiero Morini ; Luigi Cavallo
• 刊名：ACS Catalysis
• 出版年：2015
• 出版时间：September 4, 2015
• 年：2015
• 卷：5
• 期：9
• 页码：5431-5435
• 全文大小：296K
• ISSN：2155-5435

文摘

We propose a model for MgCl₂-supported Ziegler鈥揘atta catalysts, which is capable to reconcile the discrepancies emerging in the last 20 years, in which attempts have been made to rationalize experimental data by molecular models. We show that step defects on the thermodynamically more stable (104) facet of MgCl₂ can lead to sites for strong TiCl₄ adsorption. The corresponding Ti-active site is stereoeselective, and its stereoselectivity can be enhanced by coordination of Al-alkyls or Lewis bases in the close proximity. The surface energy of the step defected (104) MgCl₂ facet is clearly lower than that of the well accepted (110) facet.