Immobilization of Polyoxometalate in the Metal-Organic Framework rht-MOF-1: Towards a Highly Effective Heterogeneous Catalyst and Dye Scavenger.

Jing-Wen Sun,Guang-Hui An,Guang-Ming Li,Peng-Fei Yan,Guo-Yu Yang,Jing-Quan Sha

doi:10.1038/srep25595

Abstract

A series of three remarkable complexes [PMo12O40]@[Cu6O(TZI)3(H2O)9]4·OH·31H2O (H3TZI = 5-tetrazolylisophthalic acid; denoted as HLJU-1, HLJU = Heilongjiang University), [SiMo12O40]@[Cu6O(TZI)3(H2O)9]4·32H2O (denoted as HLJU-2), and [PW12O40]@[Cu6O(TZI)3(H2O)6]4·OH·31H2O (denoted as HLJU-3) have been isolated by using simple one-step solvothermal reaction of copper chloride, 5-tetrazolylisophthalic acid (H3TZI), and various Keggin-type polyoxometalates (POMs), respectively. Crystal analysis of HLJU 1−3 reveals that Keggin-type polyoxoanions have been fitted snuggly in the cages of rht-MOF-1 (MOF: metal−organic framework) with large cell volume in a range of 87968−88800 Å3 and large pore volume of about 68%. HLJU 1–3 exhibit unique catalytic selectivity and reactivity in the oxidation of alkylbenzene with environmental benign oxidant under mild condition in aqueous phase as well as the uptake capacity towards organic pollutants in aqueous solution.

Highlights

Polyoxometalates (POMs), as a species of significant metal oxide clusters with high negative charge and abundant topologies, have been employed in many research fields, such as catalysis, optics, magnetism, and biological medicine[1,2,3,4,5,6,7,8,9,10]
Catalytic experiments reveal that HLJU 1− 3 exhibit unique catalytic selectivity and reactivity in the oxidation of alkylbenzene under mild condition with environmental benign oxidant in aqueous phase as well as the uptake capacity towards organic pollutants in aqueous solution
X-ray diffraction analysis reveals that HLJU 1− 3 are isomorphous crystallizing in a highly symmetric space group of Fm3 m with large cell volume in the range of 87968− 88800 Å3

Summary

Introduction

Polyoxometalates (POMs), as a species of significant metal oxide clusters with high negative charge and abundant topologies, have been employed in many research fields, such as catalysis, optics, magnetism, and biological medicine[1,2,3,4,5,6,7,8,9,10]. Immobilizing POMs in porous solid materials, such as silica and activated carbon is a promising approach to stabilize POMs and optimize their catalytic performance[12,13,14,15] Among these solid supports, porous metal-organic frameworks (MOFs) offer significant advantages of high surface area and porosity over the traditional solid supports[16,17,18,19,20,21,22,23,24,25,26,27,28,29]. Catalytic experiments reveal that HLJU 1− 3 exhibit unique catalytic selectivity and reactivity in the oxidation of alkylbenzene under mild condition with environmental benign oxidant in aqueous phase as well as the uptake capacity towards organic pollutants in aqueous solution

Methods

Results

Conclusion