10.1021/ja807357r.s002
Chun-Yan Sun
Chun-Yan
Sun
Shu-Xia Liu
Shu-Xia
Liu
Da-Dong Liang
Da-Dong
Liang
Kui-Zhan Shao
Kui-Zhan
Shao
Yuan-Hang Ren
Yuan-Hang
Ren
Zhong-Min Su
Zhong-Min
Su
Highly Stable Crystalline Catalysts Based on a Microporous Metal−Organic Framework and Polyoxometalates
American Chemical Society
2009
Stable Crystalline Catalysts
activity loss
PW 12 species
acid catalyst
compound
noncoordinating guests
pore surface
hydrothermal reaction
substrate accessibility
cuboctahedral cages
copper nitrate
UV
BTC
MOF
PolyoxometalatesA series
Keggin polyanions
representative acid
Keggin polyoxometalates
TG
framework decomposition
host matrix
POM leaching
2009-02-11 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Highly_Stable_Crystalline_Catalysts_Based_on_a_Microporous_Metal_Organic_Framework_and_Polyoxometalates/2879095
A series of remarkable crystalline compounds [Cu<sub>2</sub>(BTC)<sub>4/3</sub>(H<sub>2</sub>O)<sub>2</sub>]<sub>6</sub>[H<i><sub>n</sub></i>XM<sub>12</sub>O<sub>40</sub>]·(C<sub>4</sub>H<sub>12</sub>N)<sub>2</sub> (X = Si, Ge, P, As; M = W, Mo) were obtained from the simple one-step hydrothermal reaction of copper nitrate, benzentricaboxylate (BTC), and different Keggin polyoxometalates (POMs). In these compounds, the catalytically active Keggin polyanions were alternately arrayed as noncoordinating guests in the cuboctahedral cages of a Cu-BTC-based metal−organic framework (MOF) host matrix. X-ray crystallographic analyses, TG, FT-IR, UV−vis, N<sub>2</sub> adsorption studies, and acid−base titration demonstrated their high stability and toleration for thermal and acid−base conditions. No POM leaching or framework decomposition was observed in our study. The representative acid catalytic performance of a compound containing PW<sub>12</sub> species was assessed through the hydrolysis of esters in excess water, which showed high catalytic activity and can be used repeatedly without activity loss. Moreover, catalytic selectivity, which is dependent on the molecular size of substrates, and substrate accessibility for the pore surface were observed. It is the first time that the well-defined, crystalline, MOF-supported POM compound has behaved as a true heterogeneous acid catalyst. The unique attributes of MOF and well-dispersed level of POMs prohibited the conglomeration and deactivation of POMs, which allowed for the enhancement of their catalytic properties.