Pd₃ cluster catalysis: Compelling evidence from in operando spectroscopic, kinetic, and density functional theory studies

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• 作者：Chunlin Lv ; Hao Cheng ; Wei He ; Muhammad Ishaq Ali Shah ; Congqiao Xu…
• 关键词：metal cluster catalysis ; operando studies ; active species ; cycloisomerization ; palladium
• 刊名：Nano Research
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：9
• 期：9
• 页码：2544-2550
• 全文大小：1,582 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chinese Library of Science
  Chemistry
  Nanotechnology
  
• 出版者：Tsinghua University Press, co-published with Springer-Verlag GmbH
• ISSN：1998-0000
• 卷排序：9

文摘

Identification of metal cluster catalysis is a topic that is being investigated since a long time. Here, we report a Pd3 metal cluster catalytic reaction investigated by means of operando studies. We discovered that atomically defined tri-nuclear palladium (Pd₃) is a surprisingly active catalyst for the cycloisomerization of 2-phenylethynylaniline. Operando 1H NMR spectroscopy and X-ray extended absorption fine structure (EXAFS) measurements have indicated that the structural integrity of such a catalyst remains intact throughout the reaction, which has also been confirmed by an ex situ X-ray photoelectron spectroscopy (XPS) study and catalyst recycling experiments. Kinetic data derived from operando IR spectroscopy measurements have shown that Pd₃ is the active catalytic species. Density functional theory calculations have revealed a reaction pathway consistent with the kinetic data, further supported by NMR titration and X-ray crystal structure studies. Overall, the present study presents a clear example of metal cluster catalysis.