Sandwich-type tungstophosphates in the catalytic oxidation of cycloalkanes with hydrogen peroxide

Santos, Isabel C.M.S.; Gamelas, José A. F.; Balula, Salete S.; Simões, Mário M. Q.; Neves, Maria G. P. M. S.; Cavaleiro, José A. S.; Cavaleiro, Ana M. V.

doi:10.1016/j.molcata.2006.08.051

Cited by 36 publications

(4 citation statements)

References 44 publications

(68 reference statements)

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“…and 5 h of reaction does not change significantly. This behaviour is different from other previous studies [13][14][15] what may be related to the copper center as the active center (Figure 1). The copper substituted POMs showed lower conversion data the cyclooctene oxidation.…”

Section: Resultscontrasting

confidence: 99%

Catalytic Performance of Copper-Substituted Polyoxotungstate Materials and X-Ray Structure of a New Sandwich-Type Compound

Balula

Cunha‐Silva

Santos

et al. 2008

MSF

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Mono-substituted and sandwich-type copper substituted polyoxoanions ([PW11CuO39]5− and [Cu4(H2O)2(PW9O34)2]10−) were studied as catalysts for the epoxidation of cyclooctene and geraniol, using the green oxidant H2O2, with the results suggesting good efficiency at room temperature. High selectivity and reasonable conversion data were found after the first minutes of reaction. The copper centre may be responsible for this performance and our on-going research focuses in the preparation of new materials incorporating copper into polyoxometalates (POMs). In this context, we have also isolated a new crystalline dimeric sandwich-type polyoxocoppertungstate {H7.05[Cu3WO(H2O)(CuW9O34)(Cu0.6W9O34)]}7.75−. This compound was isolated as potassium salt and structurally characterized by FTIR and single-crystal X-ray diffraction (XRD). The polyoxoanion is composed by the [CuW9O34]12− and [Cu0.6W9O34]12.8− anionic fragments, joined together by a rhomb-like arrangement of three Cu2+ and one W6+ metallic centres, all exhibiting octahedral coordination geometries.

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Section: Resultscontrasting

confidence: 99%

Catalytic Performance of Copper-Substituted Polyoxotungstate Materials and X-Ray Structure of a New Sandwich-Type Compound

Balula

Cunha‐Silva

Santos

et al. 2008

MSF

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“…Most of the homogeneous oxidation of cyclohexane catalyzed by polyoxometalates (POMs) was performed in acetonitrile solvent with H 2 O 2 , e.g. tetrabutylammonium salts of [XW 11 O 39 ] nand [XW 11 MO 39 ] (n-m)-(X = P, Si, B and M III = Fe, Mn), [5], [M 4 (H 2 O) 2 (PW 9 O 34 ) 2 ] 10-, M II = Co, Mn and M III = Fe where [Fe 4 (H 2 O) 2 (PW 9 O 34 ) 2 ] 6showed higher conversion of cyclohexane but the main product was cyclohexyl hydroperoxide [6]. Heteropolytungstic acid or HPW supported on MCM-41 [7][8][9][10] finds its place in catalysis over many organic reactions owing to the typical characteristics of the mesoporous materials of the MCM-41 type with highly ordered mesoporosity (pore size 2-10 nm) [11], large surface area, and high hydrothermal stability and acidity, making these materials as efficient catalysts in the synthesis and conversion of organic molecules.…”

Section: Introductionmentioning

confidence: 99%

Acidic and cesium salts of polyoxometalates with and without vanadium supported on MCM-41 as catalysts for oxidation of cyclohexane with H2O2

Trakarnpruk

Jatupisarnpong

2013

Appl Petrochem Res

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Acidic and cesium salts of polyoxometalate (POM) with and without vanadium supported on MCM-41 were synthesized and their catalytic activities were investigated in the oxidation of cyclohexane with H 2 O 2 under solvent-free condition. The products are cyclohexanol and cyclohexanone. The catalytic activity order is: CsV-POM/MCM [ HVPOM/MCM [ CsPOM/MCM * HPOM/ MCM [ CsVPOM [ CsPOM catalysts. High conversion and selectivity to cyclohexanone over the supported catalysts are due to redox property and high surface area. These heterogeneous catalysts can be reused.

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“…Santos et al 166 synthesized sandwich type tungstophosphates with different transition metals as an active material. Among them [Fe 4 (H 2 O) 2 (PW 9 O 34 ) 2 ] n − catalyst was found to be the most active and selective for cyclohexane oxidation reaction.…”

Section: Applications Of the Selective Oxidationsmentioning

confidence: 99%

Advances and future trends in selective oxidation catalysis: a critical review

Yadav

Mewada

Wagh

et al. 2022

Catal. Sci. Technol.

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Sandwich-type tungstophosphates in the catalytic oxidation of cycloalkanes with hydrogen peroxide

Cited by 36 publications

References 44 publications

Catalytic Performance of Copper-Substituted Polyoxotungstate Materials and X-Ray Structure of a New Sandwich-Type Compound

Catalytic Performance of Copper-Substituted Polyoxotungstate Materials and X-Ray Structure of a New Sandwich-Type Compound

Acidic and cesium salts of polyoxometalates with and without vanadium supported on MCM-41 as catalysts for oxidation of cyclohexane with H2O2

Advances and future trends in selective oxidation catalysis: a critical review

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