Article Title

Pd embedded in porous carbon (Pd@CMK-3) as an active catalyst for Suzuki reactions: Accelerating mass transfer to enhance the reaction rate

Authors

Zhencai Wang, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Wei Chen, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Zhenliang Han, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Jie Zhu, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Na Lu, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Yun Yang, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Dekun Ma, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China
Ying Chen, ARC Centre of Excellence for Functional Nanomaterials, Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia
Shaoming Huang, Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325027, China

Keywords

Pd, CMK-3, porous catalyst, Suzuki reactions, mass transfer

Abstract

Heterogeneous catalysts are promising candidates for use in organic reactions due to their advantages in separation, recovery, and environment compatibility. In this work, an active porous catalyst denoted as Pd embedded in porous carbon (Pd@CMK-3) has been prepared by a strategy involving immersion, ammonia- hydrolysis, and heating procedures. Detailed characterization of the catalyst revealed that Pd(0) and Pd(II) species co-exist and were embedded in the matrix of the porous carbon (CMK-3). The as-prepared catalyst has shown high activity toward Suzuki reactions. Importantly, if the reaction mixture was homogenized by two minutes of ultrasonication rather than magnetic stirring before heating, the resistance to mass transfer in the pore channels was significantly reduced. As a result, the reactions proceeded more rapidly and a four-fold increase in the turnover frequency (TOF) could be obtained. When the ultrasonication was employed throughout the entire reaction process, the conversion could also exceed 90% even without the protection of inert gas, and although the reaction temperature was lowered to 30 °C. This work provides a method for fabricating highly active porous carbon encapsulated Pd catalysts for Suzuki reactions and proves that the problem of mass transfer in porous catalysts can be conveniently resolved by ultrasonication without any chemical modification being necessary.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-014-0488-x

Publisher

Tsinghua University Press

Recommended Citation

Zhencai Wang,Wei Chen,Zhenliang Han,Jie Zhu,Na Lu,Yun Yang,Dekun Ma,Ying Chen,Shaoming Huang, Pd embedded in porous carbon (Pd@CMK-3) as an active catalyst for Suzuki reactions: Accelerating mass transfer to enhance the reaction rate. NanoRes.2014, 7(9): 1254–1262