Journal ArticleDOI
A green process for the epoxidation of dicyclopentadiene with aqueous H2O2 over highly efficient and stable HPW-NH2-SBA-15
TLDR
In this paper, Dicyclopentadiene dioxide (2) was synthesized using an economic and green reaction by the direct oxidation of DCPD with aqueous H2O2 over tungstic acid and aminopropyl-immobilized phosphotungstic acid on SBA-15, which was successfully obtained by the immobilization of the supported heteropolyacid (HPW) on the surface of the ordered mesoporous silica.Abstract:
Dicyclopentadiene dioxide (2) was synthesized using an economic and green reaction by the direct oxidation of dicyclopentadiene (DCPD) with aqueous H2O2 over tungstic acid and aminopropyl-immobilized phosphotungstic acid on SBA-15, which was successfully obtained by the immobilization of the supported heteropolyacid (HPW) on the surface of the ordered mesoporous silica, SBA-15, by means of chemical bonding to aminosilane groups. The as-obtained materials were characterized by N2 sorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), 31P-magic angle spinning (MAS) NMR and Raman spectroscopy. The 16% HPW-NH2-SBA-15 is highly efficient in the reaction with a DCPD conversion of 100% and (2) selectivity up to 97%. It is interesting that this material could be reused six times without any significant loss of activity and selectivity. The good stability can be attributed to the strong interaction between the amino groups on the surface of SBA-15 and HPW anions.read more
Citations
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Journal ArticleDOI
Clean transesterification process for biodiesel production using heterogeneous polymer-heteropoly acid nanocatalyst
Nabel A. Negm,Nabel A. Negm,Mohamed A. Betiha,Mohamed A. Betiha,Mosaed S. Alhumaimess,Hassan M.A. Hassan,Abdelrahman M. Rabie +6 more
TL;DR: In this paper, new hetrogeneous catalysts, in which phosphotungstic acid is chemically bonded to hydrophobic highly crosslinked poly(4-divinylbenzene-co-vinylbenzyl chloride) via a soft linker, were used in the transesterification of castor oil process.
Journal ArticleDOI
H3PW12O40 Grafted on CeO2: A High-Performance Catalyst for the Selective Catalytic Reduction of NOx with NH3
TL;DR: In this paper, tungstophosphoric acid (H3PW12O40) with a high acidic strength was grafted on CeO2 by the adsorption of HPW in a HPW solution.
Journal ArticleDOI
Graphene Oxide as Support for the Immobilization of Phosphotungstic Acid: Application in the Selective Oxidation of Benzyl Alcohol
TL;DR: In this paper, the effects of catalyst parameters and reaction conditions on the oxidation reaction of benzyl alcohol are systematically investigated, and the mechanism of deactivation was testified using the SEM images and the XPS spectrums in c (inset) and d (inet).
Journal ArticleDOI
Efficiency of Polyoxometalate-Based Mesoporous Hybrids as Covalently Anchored Catalysts.
Faiza Bentaleb,Faiza Bentaleb,Ourania Makrygenni,Ourania Makrygenni,Dalil Brouri,Dalil Brouri,Cristina Coelho Diogo,Ahmad Mehdi,Anna Proust,Anna Proust,Franck Launay,Franck Launay,Richard Villanneau,Richard Villanneau +13 more
TL;DR: It is shown that the best distribution and loading in POMs have been reached with SBA-15 functionalized with aminopropyl groups, as well as recycling tests together with catalyst filtration experiments during the reaction allowed us to preclude the hypothesis of a significant leaching of the supported catalyst.
Journal ArticleDOI
Covalent immobilization of a polyoxometalate in a porous polymer matrix: a heterogeneous catalyst towards sustainability
TL;DR: In this paper, a polyoxometalate (POM) catalyst was shown to achieve high selectivity by direct covalent immobilization in polymer matrices with uniform macropores and high specific surface areas.
References
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Journal ArticleDOI
Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores
Dongyuan Zhao,Jianglin Feng,Qisheng Huo,Nicholas A. Melosh,Glenn H. Fredrickson,Bradley F. Chmelka,Galen D. Stucky +6 more
TL;DR: Use of amphiphilic triblock copolymers to direct the organization of polymerizing silica species has resulted in the preparation of well-ordered hexagonal mesoporous silica structures (SBA-15) with uniform pore sizes up to approximately 300 angstroms.
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Vibrational investigations of polyoxometalates. 2. Evidence for anion-anion interactions in molybdenum(VI) and tungsten(VI) compounds related to the Keggin structure
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Homogeneous catalysis by transition metal oxygen anion clusters
TL;DR: In this paper, a thorough discussion of homogeneous catalysis by transition metal oxygen anion clusters (polyoxometalates), with a focus on mechanism, is provided, and a general compilation of the reactions, including catalytic electrooxidations or electroreductions, reported to date is given.
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Heteropoly Acids and Related Compounds as Catalysts for Fine Chemical Synthesis
TL;DR: In this article, a wide variety of HPAs belonging to the so-called Keggin series are the most important for catalysis and they include heteropolyanions (HPANs) which have metal-oxygen octahedra as the basic structural units.
Journal ArticleDOI
Structure of the Molecule of 12-Phosphotungstic Acid
TL;DR: The structure and formulae of the 12-phosphotungstic acid have been a subject for speculation as discussed by the authors, and Pauling proposed a structure for the molecules of 12-heteropoly acids, which gave the formula of 12phosphotonemic acid as H3[PO4.W12O18(OH)36]nH2O.