Highly Efficient Activation, Regeneration, and Active Site Identification of Oxide-Based Olefin Metathesis Catalysts

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• 作者：Kunlun Ding ; Ahmet Gulec ; Alexis M. Johnson ; Tasha L. Drake ; Weiqiang Wu ; Yuyuan Lin ; Eric Weitz ; Laurence D. Marks ; Peter C. Stair
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：September 2, 2016
• 年：2016
• 卷：6
• 期：9
• 页码：5740-5746
• 全文大小：456K
• 年卷期：0
• ISSN：2155-5435

文摘

Supported metal oxide based olefin metathesis catalysts are widely used in the chemical industry. In comparison to their organometallic catalyst cousins, the oxide catalysts have much lower activity due to the very small fraction of active sites. We report that a simple pretreatment of MoO₃/SiO₂ and WO₃/SiO₂ under an olefin-containing atmosphere at elevated temperatures leads to a 100–1000-fold increase in the low-temperature propylene metathesis activity. The performance of these catalysts is comparable with those of the well-defined organometallic catalysts. Unprecedentedly, the catalyst can be easily regenerated by inert gas purging at elevated temperatures. Furthermore, using UV resonance Raman spectroscopy and electron microscopy, we provide strong evidence that the active sites for MoO₃/SiO₂ are derived from monomeric Mo(═O)₂ dioxo species.