Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy

doi:10.1039/c7ra12407d

	Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy
	Zhao, J; Xu, MD; Liu, Q; Cao, XZ; Zeng, MF; Qi, CZ; Wang, YD; Xia R(夏锐); Wang, BY; Xia, R
刊名	RSC ADVANCES
	2018
卷号	8 期号:6 页码:3225-3236
ISSN号	2046-2069
DOI	10.1039/c7ra12407d
文献子类	Article
英文摘要	In this study, the catalytic performances of palladium supported on chitosan (Pd@CS) membrane heterogeneous catalysts have been studied from the aspects of free volume by positron annihilation Lifetime spectroscopy (PALS). The results showed that the variation in free volume hole size of the Pd@CS membrane catalyst was closely associated with microstructure evolutions, such as increase of Pd content, valence transition of Pd by reduction treatment, solvent swelling, physical aging during catalyst recycling, and so on. The PALS resuLts showed that both the mean free volume hole size of the Pd@CS membrane in the dry or swollen state (analyzed by the LT program) and its distribution (analyzed by the MELT program) are smaller than the molecue size of the reactants and products in the catalysis reaction. However, the resuLts showed that the Pd@CS membrane catalyst has excellent catalytic activity for the Heck coupling reaction of all the reactants with different molecule size. It was revealed that the molecule transport channels of the Pd@CS membrane catalyst in the reaction at high temperature was through a number of instantaneously connected free volume holes rather than a single free volume hole. This hypothesis was powerfully supported by the catalytic activity assessment resuLts of the CS Layer sealed Pd@CS membrane catalyst. Meanwhile, it was confirmed that the Leaching of Pd nanoparticles of the reused Pd@CS membrane catalyst during the recycling process was also through such instantaneously connected free volume holes.
WOS关键词	SUPPORTED PALLADIUM CATALYST ; CROSS-COUPLING REACTIONS ; FREE-VOLUME ; HIGHLY EFFICIENT ; HETEROGENEOUS CATALYSIS ; SONOGASHIRA REACTIONS ; HYBRID MICROSPHERES ; MODEL COMPOUNDS ; CO2 SEPARATION ; HECK REACTIONS
WOS研究方向	Chemistry
语种	英语
WOS记录号	WOS:000423304700052
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/285565]
专题	高能物理研究所_多学科研究中心高能物理研究所_实验物理中心高能物理研究所_粒子天体物理中心
通讯作者	Cao XZ(曹兴忠)
作者单位	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	Zhao, J,Xu, MD,Liu, Q,et al. Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy[J]. RSC ADVANCES,2018,8(6):3225-3236.
APA	Zhao, J.,Xu, MD.,Liu, Q.,Cao, XZ.,Zeng, MF.,...&曹兴忠.(2018).Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy.RSC ADVANCES,8(6),3225-3236.
MLA	Zhao, J,et al."Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy".RSC ADVANCES 8.6(2018):3225-3236.