Synthesis of a Novel Cellulose Microencapsulated Palladium Nanoparticle and Its Catalytic Activities in Suzuki鈥揗iyaura and Mizoroki鈥揌eck Reactions

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• 作者：Feiran Chen ; Mingming Huang ; Yiqun Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：May 21, 2014
• 年：2014
• 卷：53
• 期：20
• 页码：8339-8345
• 全文大小：347K
• 年卷期：v.53,no.20(May 21, 2014)
• ISSN：1520-5045

文摘

Palladium nanoparticles microencapsulated by cellulose (CelMcPd⁰) were, for the first time, developed via reduction of Pd(OAc)₂ or PdCl₂ in a cellulosic ionic liquid solvent, in which the Pd^II species were synchronously reduced to Pd⁰ nanoparticles in situ with the ionic liquid itself or with NaBH₄, followed by enveloping the Pd⁰ cores with cellulosic films using anhydrous ethanol as a coagulant. The as-prepared novel hybrid material CelMcPd⁰ proved to be a versatile and highly catalytically efficient, recyclable, and robust catalyst for a range of phosphine-free crossing Suzuki鈥揗iyaura and Mizoroki鈥揌eck reactions under mild aerobic conditions. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements have been used to characterize the catalysts. The results revealed that the palladium particles are mostly spherical in shape and estimated to be range of 5鈥?0 nm in CelMcPd⁰-1, 5鈥?0 nm in CelMcPd⁰-2, and 3鈥?5 nm in CelMcPd⁰-3. Moreover, homogeneous catalysis in Suzuki鈥揗iyaura couplings catalyzed by CelMcPd⁰-1 was evidenced from CS₂ poisoning tests. After the completion of the reaction, catalyst separation could be easily achieved by simple filtration, and the catalyst could be recycled at least six times without any loss of its high catalytic activity.