High-valent cationic metal–organic macrocycles as novel supports for immobilization and enhancement of activity of polyoxometalate catalysts

Developing a new strategy for preparing highly active and recyclable heterogeneous polyoxometalate (POM) catalysts has attracted much attention in the past decades. In this work, we prepared hexagonal terpyridine-cadmium metal–organic macrocycles ( Cd-MOMs ) with a dodeca-valent positive charge, and...

Full description

Saved in:
Bibliographic Details
Published in:Catalysis science & technology 2016-01, Vol.6 (24), p.8540-8547
Main Authors: Duan, Yunpeng, Wei, Wei, Xiao, Fei, Xi, Yaru, Chen, Shi-Lu, Wang, Jin-Liang, Xu, Yanqing, Hu, Changwen
Format: Article
Language:English
Subjects:
Acetal resins
Catalysis
Catalysts
Conversion
Epoxidation
Heterogeneity
Macrocyclic compounds
Polyoxometallates
Selectivity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Developing a new strategy for preparing highly active and recyclable heterogeneous polyoxometalate (POM) catalysts has attracted much attention in the past decades. In this work, we prepared hexagonal terpyridine-cadmium metal–organic macrocycles ( Cd-MOMs ) with a dodeca-valent positive charge, and subsequently employed them as new catalyst supports for immobilizing mono-transition-metal-substituted Keggin-type HPW 11 MO 39 4− ( PW 11 M , M = Ni, Co, Cu, Zn) polyoxometalates. Because of strong electrostatic interactions, the obtained polyoxometalate-metal–organic macrocycle ( PW 11 M-Cd-MOM or POM-MOM ) catalysts exhibit high thermal stability and insolubility in common solvents. The composite catalysts were found effective for the epoxidation of cyclooctene and sulfide oxidation with hydrogen peroxide. In the epoxidation reaction of cyclooctene, PW 11 Ni-Cd-MOM shows the highest catalyst performance with 96.4% conversion and 95.7% selectivity for epoxide. Compared with homogeneous POM and non-cyclic hybrid analogue catalysts, the conversion and selectivity of POM-MOM catalysts are both enhanced enormously, showing remarkable synergistic reactivity. Moreover, leaching tests confirmed the heterogeneity of POM-MOM catalysts and they can be recycled at least four times with no significant loss of activity.
ISSN:2044-4753
2044-4761
DOI:10.1039/C6CY02062C