文献类型：期刊文献

英文题名：TiO2-Modified Montmorillonite-Supported Porous Carbon-Immobilized Pd Species Nanocomposite as an Efficient Catalyst for Sonogashira Reactions

作者：Chen, Yuli[1];Sun, Kailang[1];Zhang, Taojun[1];Zhou, Jie[1];Liu, Yonghong[1];Zeng, Minfeng[1];Ren, Xiaorong[1];Feng, Ruokun[1];Yang, Zhen[1];Zhang, Peng[2];Wang, Baoyi[2];Cao, Xingzhong[2]

机构：[1]Shaoxing Univ, Coll Chem & Chem Engn, Res Ctr Adv Catalyt Mat & Funct Mol Synth, Zhejiang Key Lab Alternat Technol Fine Chem Proc, Shaoxing 312000, Peoples R China;[2]Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China

年份：2023

卷号：28

期号：5

外文期刊名：MOLECULES

收录：SCI-EXPANDED(收录号：WOS:000947263000001)、、WOS

基金：This research was funded by the National Natural Science Foundation of China (Grant No. 11875193, 12175149, 11475114); the Zhejiang Provincial Fundamental Public Welfare Research Project of China (Grant No. LGG18E030004); and the Shaoxing Key Science and Technology Innovation Team Project.

语种：英文

外文关键词：Sonogashira reactions; heterogeneous catalysis; structure-performance relations; positron annihilation

外文摘要：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@Pd-0 nanocomposites were confirmed using a combined characterization with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N-2 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@Pd-0 showed a high surface area of 108.9 m(2)/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.