A Stable Polyoxometalate-Based Metal–Organic Framework as Highly Efficient Heterogeneous Catalyst for Oxidation of Alcohols

Abstract

Cu ΙΙ (pzc) 2 (pz) 4.5 {P 2 W 18 O 62 }]•6H 2 O (HENU-1, HENU = Henan University; Hpzc = pyrazine-2-carboxylic acid, pz = pyrazine), was successfully isolated by a one-step hydrothermal method. In this compound, the {P 2 W 18 } polyanion acts as a seven-connected linker bridging adjacent 2D double-layer networks, as well as a template to induce the formation of the desired 3D framework. Particularly, the pz ligands are generated from pzc ligands in situ during the reaction process. HENU-1 exhibits not only good stability in air but also tolerance to acidic and basic media. It was first employed as a highly efficient heterogeneous catalyst for the oxidation of 1-phenylethanol into acetophenone, which shows 97% yield using tert-butyl hydroperoxide as oxidant with a turnover frequency of up to 9690•h −1 , and was reused for at least five cycles without significant catalytic activity loss. No POM leaching or framework decomposition was observed in our study.

POM@MOF Hybrids: Synthesis and Applications

“…Recently, this group also prepared the PV2Mo10@NU-1000 catalyst by using the same method and the synthesized material showed a full conversion of CEES, with O2 as the oxidant. In addition to the well-known MOFs, several other POM@MOF hybrid materials, including [Co(BBPTZ)3][HPMo12O40]•24H2O and [Cu I 6(trz)6(PW12O40)2], have been synthesized and applied for ODS [88], the oxidation of aryl alkenes [89,90], alkylbenzenes [91], and alcohols [92] (see Table 2).…”

“…Accordingly, the ZIF-8@PW12 material was insoluble in hydrophilic solvents. The ZIF- [88], the oxidation of aryl alkenes [89,90], alkylbenzenes [91], and alcohols [92] (see Table 2).…”

Polyoxometalate‐Based Metal Organic Frameworks: Recent Advances and Challenges

“…[36][37][38][39][40] However, the disadvantages of POMs, Such an open framework realizes the good dispersion of POMs and exposes more active sites for heterogeneous catalysis of the selective oxidation of aryl alkenes to aldehydes. [33] Reprinted (adapted) with permission from Ref. [33] Copyright 2018 American Chemical Society.…”

“…For these reasons, the synthesis of POM‐based MOF, could enable a strategy for building multiphase catalysis. Ma et al [33] . synthesized two new POM‐based MOFs by hydrothermal method with the chemical formulae [Co(BBTZ) 2 ][H 3 BW 12 O 40 ] ⋅ 10H 2 O ( 1 ) and [Co 3 (H 2 O) 6 (BBTZ) 4 ][BW 12 O 40 ] ⋅ NO 3 ⋅ 4H 2 O ( 2 ), (BBTZ=1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzo), which were used for the selective oxidation of olefins to aldehydes (Figure 4).…”

Crystal Structure and Reversible Photochromism of Pb(II)‐N,N‐Dimethylformamide Modified Keggin‐Type Polyoxometalates

“…In recent years, photochromic materials have attracted much attention of researchers because of their potential applications in many fields, such as optical switching, information storage, nano machines, ink‐free printing, chemical sensors, and even biology . Polyoxometalates (POMs), as metal oxide clusters formed by self‐assembly of early transitional metal (e.g., W, Mo, V, Nb, and Ta) salt at different pH solutions, can be widely used in medicine, catalysis, electrochemistry, and sensors, due to their redox properties, acidity, and diversity in composition and structures . It is worth mentioning here that POMs, as inorganic materials, have also been applied in the study of solid‐state photochromic materials .…”