Effect of cobalt location in Keggin-type heteropoly catalysts on aerobic oxidation of cyclooctane: Experimental and theoretical study

Karcz, Robert; Niemiec, Piotr; Pamin, Katarzyna; Połtowicz, Jan; Kryściak-Czerwenka, Joanna; Napruszewska, Bogna D.; Michalik-Zym, A.; Witko, Małgorzata; Tokarz-Sobieraj, Renata; Serwicka, Ewa M.

doi:10.1016/j.apcata.2017.05.035

Cited by 29 publications

(22 citation statements)

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“…Heteropolyoxometalate compounds (HPCs) as a rich class of early transition metal oxide clusters have been studied in terms of surface chemistry and catalytic properties . Among the various structures of HPCs, Keggin‐type anions with the unique features of strong intrinsic acidity and redox potentials have gained considerable popularity in the area of oxidation catalysis . The high solubility of HPCs in aqueous and oxygen‐containing organic solvents leads to difficulties in respect of their separation and recovery .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Rezvani

Khandan

2018

Applied Organom Chemis

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A new nanocomposite (FeW 11 V@CTAB-MMT) was designed on the basis of vanadium-substituted tungstoferrate (FeW 11 V) and cetyltrimethylammonium bromide-modified montmorillonite (CTAB-MMT) as an efficient nanocatalyst for oxidative desulfurization (ODS) of gasoline. The synthesized catalyst was characterized using various techniques. To evaluate the catalytic activity of FeW 11 V@CTAB-MMT, ODS was carried out using a mixture of aqueous acetic acid and hydrogen peroxide solution as an oxidant and acetonitrile solvent as an extractant. The ODS results revealed that the removal efficiencies of thiophene, benzothiophene and dibenzothiophene were more than 97% in the presence of the FeW 11 V@CTAB-MMT catalyst at 35°C after 1 h. Kinetics of the catalytic ODS reactions was found to be pseudo-first-order. The prepared heterogeneous catalyst was found to be reusable for five runs without a discernible decrease in its activity. The current research provides insight into a new catalytic system for the ODS process for the deep removal of hazardous sulfur molecules from gasoline.

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Rezvani

Khandan

2018

Applied Organom Chemis

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“…This splitting was the consequence of the vacancy resulting of the removal of one W–O unit, that leads to a decrease in the symmetry of the central unit PO 4 . Therefore, this is evidence that the lacunar salt was formed …”

Section: Resultsmentioning

confidence: 72%

Cesium‐Exchanged Lacunar Keggin Heteropolyacid Salts: Efficient Solid Catalysts for the Green Oxidation of Terpenic Alcohols with Hydrogen Peroxide

2020

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In this work, an innovative and green oxidative process to convert renewable and abundant raw material to more value‐added fine chemicals was developed. Hydrogen peroxide, an environmentally benign oxidant, was used in Cs–exchanged lacunar Keggin heteropolyacid salts‐catalyzed oxidation reactions of the terpenic alcohols (i. e., nerol was the model molecule). The activity of most outstanding catalyst (Cs8SiW11O39) was compared with various catalysts. Epoxides and aldehydes, which are an attractive feedstock for fragrance and pharmaceutical industries were selectively obtained. Lacunar Keggin heteropolyacid salts containing cesium as the counter ion (i. e., Cs7PW11O39, Cs7PMo11O39 and Cs8SiW11O39) were easily synthesized and characterized by infrared spectroscopy, powdered X‐rays diffraction, X‐rays dispersive spectroscopy, scanning electronic microscopy, thermal analysis, porosimetry analyses, diameter and pores distribution. The influences of the main reaction variables such as catalyst concentration, the stoichiometry of the reactants and reaction temperature were evaluated. The reaction scope was successfully extended to the other terpenic alcohols. The Cs8SiW11O39 was the most active and selective lacunar salt. After five cycles of successive reuse, no loss of catalytic activity or selectivity was observed.

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“…For the studied systems, several lower-lying electronic states, as well as a vibrational analysis, were calculated. In our previous calculations [42], the effect of cobalt location in Keggin-type heteropoly acts as a catalyst for the aerobic oxidation of cyclooctane.…”

Section: Introductionmentioning

confidence: 98%

“…3− HPA causes a significant increase in its oxidizing power, whereas the same cation introduced into the PMo 12 O 40 3− system minimally increases its oxidizing abilities. Karcz et al [42] compared heteropolyacid systems, modified by a cobalt cation in the position of the central ion and addenda atom, which showed that both cobalt locations and the chemical character of other addenda atoms factor into the catalytic activity of the aerobic liquid-phase oxidation of cyclooctane. In recent years, the ability of heteropoly systems, modified by transition metal, to form complexes with CO 2 has been studied.…”

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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Effect of cobalt location in Keggin-type heteropoly catalysts on aerobic oxidation of cyclooctane: Experimental and theoretical study

Cited by 29 publications

References 57 publications

Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Cesium‐Exchanged Lacunar Keggin Heteropolyacid Salts: Efficient Solid Catalysts for the Green Oxidation of Terpenic Alcohols with Hydrogen Peroxide

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

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Effect of cobalt location in Keggin-type heteropoly catalysts on aerobic oxidation of cyclooctane: Experimental and theoretical study

Cited by 29 publications

References 57 publications

Synthesis and characterization of a new nanocomposite (FeW11V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Synthesis and characterization of a new nanocomposite (FeW11V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Cesium‐Exchanged Lacunar Keggin Heteropolyacid Salts: Efficient Solid Catalysts for the Green Oxidation of Terpenic Alcohols with Hydrogen Peroxide

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

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Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline

Synthesis and characterization of a new nanocomposite (FeW₁₁V@CTAB‐MMT) as an efficient heterogeneous catalyst for oxidative desulfurization of gasoline