• Title/Summary/Keyword: Polyoxometalates (POMs)

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Nanohybridization of Polyoxometalate and Nanomaterials for Electrochemical Application (전기 화학 응용을 위한 폴리옥소메탈레이트와 나노물질의 나노하이브리드화)

  • Yang, MinHo;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • v.29 no.4
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    • pp.363-368
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    • 2018
  • Polyoxometalates (POMs) have outstanding properties and a great deal of potential for electrochemical applications. As POMs are highly soluble, the implementation of POMs in various functional materials is required to fully use their potential in electrochemical devices. Here, we will review the recently developed immobilization methods to incorporate POMs into conductive nanomaterials, such as nanocarbons and conducting polymers. Various immobilization strategies involve POMs entrapped in conducting polymer matrix and integration of POMs into nanocarbons using a Langmuir-Blodgett technique, a layer-by-layer self-assembly, and an electrochemical in-situ polymerization. In addition, we will review a variety of electrochemical applications including electrocatalysts for water oxidation, lithium-ion batteries, supercapacitors, and electrochemical biosensors.

Adsorption Properties of Keggin-type Polyoxometalates on Carbon Based Electrode Surfaces and Their Electrocatalytic Activities

  • Choi, Su-Hee;Kim, Jong-Won
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.810-816
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    • 2009
  • The interactions between four Keggin-type POMs (${SiW_{12}O_{40}}^{4-},\;{PW_{12}O_{40}}^{3-},\;{SiMo_{12}O_{40}}^{4-},\;and\;{PMo_{12}O_{40}}^{3-}$) and glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) surfaces are investigated in a systematic way. Electrochemical results show that molibdate series POMs adsorb relatively stronger than tungstate POMs on GC and HOPG surfaces. Adsorption of POMs on HOPG electrode surfaces is relatively stronger than on GC surfaces. ${SiMo_{12}O_{40}}^{4-}$ species exhibits unique adsorption behaviors on HOPG surfaces. Surface-confined ${SiMo_{12}O_{40}}^{4-}$ species on HOPG surfaces exhibit unique adsorption behaviors and inhibit the electron transfer from the solution phase species. The catalytic activity of the surface-confined POMs for hydrogen peroxide electroreduction is also examined, where ${PW_{12}O_{40}}^{3-}$ species adsorbed on GC surfaces exhibits the highest catalytic efficiency among the investigated POM modified electrode systems.

Aluminium Salt of Phosphomolybdic Acid Fabricated by Nanocasting Strategy: An Efficient System for Selective Oxidation of Benzyl Alcohols

  • Aliyan, Hamid;Fazaeli, Razieh;Habibollahi, Nasibeh
    • Journal of the Korean Chemical Society
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    • v.56 no.5
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    • pp.591-596
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    • 2012
  • Preparation of $AlPMo_{12}O_{40}$ (AlPMo) salts, supported on mesostructured SBA-15 silica, by the reaction deposition strategy causes the formation of isolated AlPMo nanocrystals inside the nanotubular channels. The remarkable characteristic of the SBA-15 structure is that all the cylindrical pores are connected by some small channels. This makes the whole pore system in SBA-15 three-dimensional. We have used 2D hexagonal SBA-15 silicas as hard templates for the nanofabrication of AlPMo salt nanocrystal. The oxidation of alcohols occurs effectively and selectively with $H_2O_2$ as the oxidant. AlPMo salt nanocrystal was used as the catalyst.

One-pot Synthesis of Dihydropyrimidinones Using Polyoxometalate Tri-supported Transition Metal Complexes (Polyoxometalate Tri-supported Transition Metal Complexes를 이용한 Dihydropyrimidinones의 one-pot 합성)

  • Fazaeli, Razieh;Aliyan, Hamid;Mohammadifar, Foroogh;Zamani, Amir Abbas;Bagi, Mohammad Javad
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.666-672
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    • 2011
  • The catalytic activity of an inorganic-organic complex with a vanadium-substituted polyoxometalate 1, formulated as [Cu(2,2'-bipy)]$[Cu(2,2'-bipy)_2]_2[PMo_8V_6O_{42}]{\cdot}1.5H_2O$ was studied in the Biginelli reactions. The obtained results showed that, in the one-pot synthesis of dihydropyrimidinones, the turnover frequencies (TOF) for the [Cu(2,2'-bipy)]$[Cu(2,2'-bipy)_2]_2[PMo_8V_6O_{42}]{\cdot}1.5H_2O$ catalyst were higher than the $H_3PMo_{12}O_{40}$ catalyst.