文献类型：期刊文献

英文题名：Correlation of adsorbed and embedded palladium species in chitosan composite nanofibers with their catalytic activities for Suzuki reactions

作者：Su, Baogang[1];Zhang, Qi[1];Shao, Linjun[1];Zhou, Shujing[2];Li, Jinjing[2];Du, Yijun[1];Qi, Chenze[1,2]

机构：[1]Shaoxing Univ, Zhejiang Key Lab Alternat Technol Fine Chem Proc, Shaoxing 312000, Zhejiang Provin, Peoples R China;[2]Jiamusi Univ, Sch Pharm, Jiamusi 154007, Heilongjiang, Peoples R China

年份：2022

卷号：168

外文期刊名：JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS

收录：SCI-EXPANDED(收录号：WOS:000813012000007)、、EI(收录号：20222212179218)、Scopus(收录号：2-s2.0-85130912823)、WOS

基金：The authors acknowledge the financial support from the NationalNatural Science Foundation of China (No. 12075154 and 11905132) .

语种：英文

外文关键词：Palladium; Adsorb; Embed; Catalytic activity; PALS

外文摘要：Heterogeneous palladium catalysts play an important role in the synthetic organic chemistry. Palladium species have been adsorbed on the surface of solid matrices or embedded inside solid matrices to prepare recyclable heterogeneous catalysts. Due to the different surrounding environment, these two type palladium species had different electronic properties and catalytic performances. In this study, we fabricated three series of chitosan composite nanofibers with adsorbed and embedded palladium species. Their fiber morphologies and chemical structures were characterized by SEM and FT-IR, respectively. Positron annihilation lifetime spectra (PALS) showed that the intensities (I-3) of o-Ps annihilations were all linearly decreased with the increase of palladium contents in the chitosan composite nanofibers. Moreover, compared with the palladium adsorbed chitosan composite nanofibers, the palladium embedded chitosan composite nanofibers had stronger o-Ps annihilation ability, which could be ascribed to the stronger electron donating property of embedded palladium species and higher crosslinking of chitosan molecules by embedded palladium species. At last, the I3 values were successfully correlated with the rate constants of chitosan supported palladium composite nanofibers catalyzed Suzuki re-actions of iodobenzene with phenylboric acid. Therefore, we have developed a facile method to distinguish the adsorbed and embedded palladium species by PALS, which can be further related with their catalytic performance.