文献类型：期刊文献

英文题名：Microstructure-stability relations studies of porous chitosan microspheres supported palladium catalysts

作者：Zeng, Minfeng[1];Zhang, Xin[1];Qi, Chenze[1];Zhang, Xian-Man[1]

机构：[1]Shaoxing Univ, Inst Appl Chem, Zhejiang 312000, Peoples R China

年份：2012

卷号：51

期号：5

起止页码：730

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：SCI-EXPANDED(收录号：WOS:000311196100006)、、Scopus(收录号：2-s2.0-84866537290)、WOS

基金：The authors acknowledge the financial support from the National Natural Science Foundation of China and Key Sci-Tech Innovation Team Project of Zhejiang Province, China.

语种：英文

外文关键词：Chitosan porous microsphere; Palladium catalyst; Coupling reaction; Compatibility

外文摘要：In this study, polyethylene glycol (PEG) with different molecular weight, polyvinyl pyrrolidone (PVP), and polyvinyl alcohol (PVA), are chosen as porogens for preparing chitosan base porous microsphere supported palladium catalyst for coupling reactions. The pore structure of the microspheres was controlled by the compatibility of chitosan and counterpart polymers. The prepared porous chitosan microspheres supported palladium heterogeneous catalysts have been evaluated using the well-established Ullmann reductive homocoupling and the Heck cross-coupling reactions. The activities, stabilities and recyclability of the porous chitosan microspheres supported palladium catalysts are not only highly dependent upon the surface areas of the solid supports, but also upon the chemical properties of the water-soluble polymers. The degradation of the prepared heterogeneous palladium catalysts is mainly caused by a combination of the palladium leaching and the morphological transformation of the palladium species from the amorphous into the crystals. (C) 2012 Elsevier B.V. All rights reserved.