TiO<sub>2</sub>-Modified Montmorillonite-Supported Porous Carbon-Immobilized Pd Species Nanocomposite as an Efficient Catalyst for Sonogashira Reactions
Yuli Chen,
Kailang Sun,
Taojun Zhang,
Jie Zhou,
Yonghong Liu,
Minfeng Zeng,
Xiaorong Ren,
Ruokun Feng,
Zhen Yang,
Peng Zhang,
Baoyi Wang,
Xingzhong Cao
Affiliations
Yuli Chen
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Kailang Sun
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Taojun Zhang
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Jie Zhou
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Yonghong Liu
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Minfeng Zeng
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Xiaorong Ren
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Ruokun Feng
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Zhen Yang
Research Center of Advanced Catalytic Materials and Functional Molecular Synthesis, Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
Peng Zhang
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
Baoyi Wang
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
Xingzhong Cao
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
In this study, a combination of the porous carbon (PCN), montmorillonite (MMT), and TiO2 was synthesized into a composite immobilized Pd metal catalyst (TiO2-MMT/PCN@Pd) with effective synergism improvements in catalytic performance. The successful TiO2-pillaring modification for MMT, derivation of carbon from the biopolymer of chitosan, and immobilization of Pd species for the prepared TiO2-MMT/PCN@Pd0 nanocomposites were confirmed using a combined characterization with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption–desorption isotherms, high-resolution transition electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. It was shown that the combination of PCN, MMT, and TiO2 as a composite support for the stabilization of the Pd catalysts could synergistically improve the adsorption and catalytic properties. The resultant TiO2-MMT80/PCN20@Pd0 showed a high surface area of 108.9 m2/g. Furthermore, it exhibited moderate to excellent activity (59–99% yield) and high stability (recyclable 19 times) in the liquid–solid catalytic reactions, such as the Sonogashira reactions of aryl halides (I, Br) with terminal alkynes in organic solutions. The positron annihilation lifetime spectroscopy (PALS) characterization sensitively detected the development of sub-nanoscale microdefects in the catalyst after long-term recycling service. This study provided direct evidence for the formation of some larger-sized microdefects during sequential recycling, which would act as leaching channels for loaded molecules, including active Pd species.
