文献类型：期刊文献

英文题名：Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd-0 Nanoparticle Catalysts

作者：Shu, Guiqing[1];Zhao, Jing[1];Zheng, Xiu[1];Xu, Mengdie[1];Liu, Qi[1];Zeng, Minfeng[1]

机构：[1]Shaoxing Univ, Coll Chem & Chem Engn, Zhejiang Key Lab Alternat Technol Fine Chem Proc, Shaoxing 312000, Peoples R China

年份：2019

卷号：11

期号：5

外文期刊名：POLYMERS

收录：SCI-EXPANDED(收录号：WOS:000480531700010)、、WOS

基金：This research was funded by the National Natural Science Foundation of China (Grant No. 11875193 and 11475114), Zhejiang Provincial Fundamental Public Welfare Research Project (Grant No. LGG18E030004), and University Students' Science and Technology Innovation Activity Plan Project of Zhejiang Province (Grant No. 2018R432012).

语种：英文

外文关键词：polyethylene oxide; montmorillonite clays; Pd catalysis; catalytic composite; positron annihilation

外文摘要：In this study, montmorillonite (MMT) was modified by intercalating polyethylene oxide (PEO) macromolecules between the interlayer spaces in an MMT-water suspension system. X-ray diffraction results revealed that the galleries of MMT were expanded significantly after intercalation of different loading of PEO. MMT/PEO 80/20 composite was chosen as the support platform for immobilization of Pd species in preparing novel heterogeneous catalysts. After immobilization of Pd species, the interlayer spacing of MMT/PEO (80/20) (1.52 nm) was further increased to 1.72 nm (Pd2+@MMT/PEO) and 1.73 nm (Pd-0@MMT/PEO), confirming the well-immobilization of the Pd species in the interlayer spaces of PEO-modified MMT. High-resolution transmission electron microscopy (HR-TEM) observation results confirmed that Pd nanoparticles were confined inside the interlayer space of MMT and/or dispersed well on the outer surface of MMT. The conversion of Pd2+ to Pd-0 species was evidenced by binding energy characterization with X-ray photo electron spectroscopy (XPS). The microstructure variation caused by the Pd immobilization was sensitively detected by positron annihilation lifetime spectroscopy (PALS) studies. The prepared Pd-0@MMT/PEO (0.2/80/20) catalytic composite exhibits good thermal stability up to around 200 degrees C, and it showed high activities for Heck reactions between aryl iodides and butyl acrylates and could be recycled for five times. The correlations between the microstructure and properties of the Pd@MMT/PEO catalytic composites were discussed.