文献类型：期刊文献

英文题名：Microstructure and catalytic performances of chitosan intercalated montmorillonite supported palladium (0) and copper (II) catalysts for Sonogashira reactions

作者：Liu, Qi[1];Xu, Mengdie[1];Zhao, Jing[1];Yang, Zhen[1];Qi, Chenze[1];Zeng, Minfeng[1];Xia, Rui[1];Cao, Xingzhong[2];Wang, Baoyi[2]

机构：[1]Shaoxing Univ, Coll Chem & Chem Engn, 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：2018

卷号：113

起止页码：1308

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：SCI-EXPANDED(收录号：WOS:000432503100150)、、Scopus(收录号：2-s2.0-85044153885)、WOS

基金：The authors acknowledge the financial support from the National Natural Science Foundation of China (grant number: No. 11475114 and 11575117), and Zhejiang Province Fundamental Public Welfare Research Project (grant number: No. LGG18E030004). Professor Y. Lin (Institute of Materials Science and Department of Chemistry, University of Connecticut) is appreciated for his valuable suggestions and discussions.

语种：英文

外文摘要：In this study, an efficient heterogeneous catalytic material including Pd-0 nanoparticles and Cu2+ cations supported on montmorillonite/chitosan (MMT/CS) composite was prepared by solution intercalation and complexion methods. The valence states of Pd (both Pd(0) and Pd(II) coexisting) and Cu (mainly Cu(II)) of the Pd/Cu2+@MMT/CS catalyst were confirmed by the X-ray photoelectron spectroscopy (XPS) characterization. The d(001) spacing was enlarged from 1.25 nm (MMT) to 1.94 nm (Pd-0/Cu2+@MMT/CS). Pd-0/Cu2+CMMT/CS catalyst had obviously bigger specific surface area (S-BET) and total pore volume (V-p) than pure MMT. High resolution transmission electron microscopy (HR-TEM) observation of the Pd-0/Cu2+CMMT/CS catalyst showed that separated Pd nanoparticles sized below 3 nm dispersed well both in the interlayer space and surface of MMT layers. The positron annihilation lifetime spectroscopy (PALS) was very sensitive to the microstructure changes caused by the formation of nano particles Pd after reduction of Pd2+/Cu2+@MMT/CStoPd(0)/Cu2+@MMT/CS. The prepared Pd-0/Cu2+@MMT/CS catalysts are highly active for the Sonogashira reactions of aromatic halides and alkynes in H2O/ether solution, and can be recycled 6 times. The leaching of Cu species is much quicker than Pd species during recycling, which should be the main reason for the decrease in efficiency of the recycled Pd-0/Cu2+@MMT/CS catalysts. (C) 2018 Published by Elsevier B.V.