Heterogeneous Catalytic Oxidation of Cyclohexane with H2O2 Catalyzed by Cs- and TBA-salts of Cu- and Mn-Polyoxotungstates on MCM-41

Trakarnpruk, Wimonrat

doi:10.7763/ijcea.2015.v6.464

Cited by 2 publications

(1 citation statement)

References 21 publications

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“…A review of the literature shows greater attention given to systems where the cobalt cation (Co 2+ ) occupies the position of the addenda atom . Modified systems, usually synthesized as various salts, as well as the comparison with systems modified by other transition metals, were tested in oxidation reactions in the presence of hydrogen peroxide [17][18][19][20][21][22], molecular oxygen [23][24][25][26][27][28], air [29][30][31][32][33], iodosylarenes [35,36], or t-butyl hydroperoxide [37,38]. Cobalt-modified Keggin heteropolyanin exhibits high catalytic activity and selectivity in processes such as oxidation of cyclohexane [26,27,35,37,38,40], esterification of n-butanol [25,39], epoxidation of olefins (cyclohexane, 1-hexene, norbornene, cyclooctene) [25], phenol oxidation [23], oxidation of methyl isobutyrate [24], oxidation of alpha-pinene [40], oxidation of alcohols 2-propanol [19] and hexanol [20], and lactonization of diols [22].…”

Section: Introductionmentioning

confidence: 99%

Oxygen Adsorption and Activation on Cobalt Center in Modified Keggin Anion-DFT Calculations

Tokarz-Sobieraj

Niemiec

2020

Catalysts

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The influence of the cobalt cation geometric environment on catalytic activity, namely, oxygen adsorption and its activation, was investigated by exploring two groups of systems. The first group was formed by cobalt cation complexes, in which the Co2+ was surrounded by water-H2O or acetonitrile-CH3CN solvent molecules. This represents heteropolyacids salts (ConH3-nPW(Mo)12O40), where the Co2+ acts as a cation that compensates for the negative charge of the Keggin anion and is typically surrounded by solvent molecules in that system. The second group consisted of tungsten or molybdenum Keggin anions (H5PW11CoO39 and H5PMo11CoO39), having the Co2+ cation incorporated into the anion framework, in the position of one addenda atom. Detailed NOCV (Natural Orbitals for Chemical Valence) analysis showed that, for all studied systems, the σ-donation and σ-backdonation active channels of the electron transfer were responsible for the creation of a single Co-OO bond. Depending on the chemical/geometrical environment of the Co2+ cation, the different quantities of electrons were flown from the Co2+ 3d orbital to the π* antibonding molecular orbitals of the oxygen ligand, as well as in the opposite direction. In molybdenum and tungsten heteropolyacids, modified by Co2+ in the position of the addenda atom, activation of O2 was supported by a π-polarization process. Calculated data show that the oxygen molecule activation changed in the following order: H5PMo11CoO39 = H5PW11CoO39 > Co(CH3CN)52+ > Co(H2O)52+.

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Section: Introductionmentioning

confidence: 99%

Oxygen Adsorption and Activation on Cobalt Center in Modified Keggin Anion-DFT Calculations

Tokarz-Sobieraj

Niemiec

2020

Catalysts

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A comprehensive and updated review of studies on the oxidation of cyclohexane to produce ketone-alcohol (KA) oil

Abutaleb

Ali

2021

Reviews in Chemical Engineering

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Oxidation of cyclohexane is an essential chemical reaction for the industrial manufacture of cyclohexanol and cyclohexanone. These two compounds, together known as ketone–alcohol (KA) oil, are the main feedstock for nylon 6 and nylon 6,6 productions. Several types of catalysts and reaction conditions have been used for cyclohexane oxidation. This paper presents a thorough literature review of catalytic materials used for cyclohexane oxidation to produce KA oil using oxygen, air and other oxidizing agents as well as utilizing different solvents. This review covers research and development reported over the years 2014–2020. This review aims to comprehend the type of catalysts, solvents, oxidants and other reaction parameters used for the oxidation of cyclohexane. Three types of cyclohexane oxidation processes namely thermocatalytic, photocatalytic and microwave-assisted catalytic have been reported. The results of the review showed that metal and metal oxide loaded silica catalysts performed excellently and provided high selectivity of KA oil and cyclohexane conversion. The use of peroxides is not feasible due to their high price compared to air and oxygen. Gold nanoparticles supported on silica performed with high selectivity and good conversion. The use of hydrochloric acid as an additive was found very effective to enhance the photocatalytic oxidation of cyclohexane. Water on the catalyst surface enhanced the reactivity of the photocatalysts since it helps in the generation of hydroxyl radicals.

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Heterogeneous Catalytic Oxidation of Cyclohexane with H2O2 Catalyzed by Cs- and TBA-salts of Cu- and Mn-Polyoxotungstates on MCM-41

Cited by 2 publications

References 21 publications

Oxygen Adsorption and Activation on Cobalt Center in Modified Keggin Anion-DFT Calculations

Oxygen Adsorption and Activation on Cobalt Center in Modified Keggin Anion-DFT Calculations

A comprehensive and updated review of studies on the oxidation of cyclohexane to produce ketone-alcohol (KA) oil

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