Over– and low–exchanged Co/BEA catalysts: General characterization and catalytic behaviour in ethane ammoxidation

Essid, Safaa; Ayari, Faouzi; Bulánek, Roman; Vaculík, Jan; Mhamdi, Mourad; Delahay, Gérard; Ghorbel, Abdelhamid

doi:10.1016/j.cattod.2017.08.027

Cited by 11 publications

(8 citation statements)

References 42 publications

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“…These reduction maxima were assigned to the reduction of CoO x occurring outside and inside the zeolite structure. [41,42] The intensity of these reduction peaks were much greater than in the case of the sample obtained by ion-exchange indicating higher contribution of Co 3+ oxide species. Moreover, in the case of the Co/BEA/s sample, above 600 °C any reduction accrued which may suggest On the TPR profile of Fe-containing BEA three maxima appeared confirming multistep reduction of Fe 3+ in cations or oxo-cations form [41,43].…”

Section: Resultsmentioning

confidence: 80%

Design of Co, Cu and Fe–BEA Zeolite Catalysts for Selective Conversion of Lactic Acid into Acrylic Acid

et al. 2019

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Design of the catalytic properties and structure of zeolite materials play a key role in efficient transformation of biomass to sustainable chemicals. In the present study, we have designed theoretical and experimental approach for the production of acrylic acid (AA) from lactic acid (LA) over zeolite catalysts. Various BEA zeolites modified with metals (Co, Cu and Fe) were prepared using ion exchange and sonication methods. In the theoretical studies the metal M-O-M dimers have been found to be stable above oxygen bound with aluminium centers of BEA zeolite. The mechanism of direct LA dehydration over the Co-, Cu-and Fe-BEA zeolites has been proposed. Experimentally, the investigated catalysts trend in following byproduct formation: AA, propionic acid (PA), 2,3-pentanedione (2,3-PD) or acetaldehyde (AC). The best selectivity towards acrylic acid was achieved in the presence of the Co-and Cu-BEA catalysts prepared by the sonication method.

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Section: Resultsmentioning

confidence: 80%

Design of Co, Cu and Fe–BEA Zeolite Catalysts for Selective Conversion of Lactic Acid into Acrylic Acid

et al. 2019

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“…The metal species change process is that Co 3 O 4 is reduced to Co 2+ at the first two peaks. Co 2+ species are reported in the literature to be difficult to reduce [ 26 , 29 , 35 , 38 ]. Therefore, this usually occurs in the high temperature section.…”

Section: Resultsmentioning

confidence: 99%

Collaborative Purification of Tert-Butanol and N2O over Fe/Co-Zeolite Catalysts

Liu

Dai

et al. 2023

IJERPH

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N2O is a greenhouse gas and a candidate oxidant. Volatile organic pollutants (VOCs) have caused great harm to the atmospheric ecological environment. Developing the technique utilizing N2O as the oxidant to oxidize VOCs to realize the collaborative purification has significant importance and practical value for N2O emission control and VOC abatement. Therefore, the study of N2O catalytic oxidation of tert-butanol based on zeolite catalysts was carried out. A series of molecular sieves, including FER, MOR, ZSM-5, Y, and BEA, were selected as the catalyst objects, and the 1.5% wt Fe and Co were, respectively, loaded on the zeolite catalysts via the impregnation method. It was found that the catalytic performance of BEA was the best among the molecular sieves. Comparing the catalytic performance of Fe-BEA under different load gradients (0.25~2%), it was found that 1.5% Fe-BEA possessed the best catalytic activity. A series of characterization methods showed that Fe3+ content in 1.5% Fe-BEA was the highest, and more active sites formed to promote the catalytic reaction. The α-O in the reaction eventually oxidized tert-butanol to CO2 over the active site. The Co mainly existed in the form of Co2+ cations over Co-BEA samples; the 2% Co-BEA possessing higher amounts of Co2+ exhibited the highest activity among the prepared Co-BEA samples.

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“…Given the fact that AN is produced as a by-product during acrylonitrile manufacture, the growing demand for acrylonitrile products has led to a severe AN shortage mainly in the pharmaceutical industry [10] . However, the unexpected AN shortages can offer the opportunity for scientists to develop novel C 2 H 6 ammoxidation catalysts [11,12] .…”

Section: Will the World Have Enough Ethane?mentioning

confidence: 99%

“…Ethane (kinetic diameter d = 4.44 Å [11] ), ethylene (d = 4.00 Å [11] ), dioxygen (d = 3.46 Å [15] ) and NH 3 (d = 2.90 Å [26] ) molecules are accessible only to the main channels and gmelinite cages of offretite. Nevertheless, CH 3 CN (d = 4.97 Å [11] ) produced during ammoxidation would be trapped inside the gmelinite cages and then oxidized into CO 2 (selectivity toward CO 2 ≥ 92%). The hydrocarbon(s) molecules (reactants or intermediate), which have no access to the hexagonal prisms and cancrinite cages, will be oxidized over amorphous MoO 3 (E g = 3.00 eV in Fig.…”

Section: Off and Fer Issued Catalystsmentioning

confidence: 99%

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Acetonitrile Synthesis via Ammoxidation: Mo/zeolites Catalysts Screening

Ayari

Mannei

Asedegbega–Nieto

et al. 2020

Fine Chemical Engineering

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Mo/zeolites catalysts were investigated in ethane and ethylene ammoxidation into acetonitrile. The catalysts were prepared either in solid‒solid or liquid‒solid interface after varying different parameters. The stabilization of Mo species upon the exchange is dependent on the hydrophilic/hydrophobic character of the zeolite and the type of Mo precursor. In fact, zeolites with low Si/Al molar ratios should be avoided due to their higher dehydration enthalpy values (Δdehyd.H). On the other hand, the use of MoOCl4, Mo(CO)6 and MoCl3 precursors and zeolites with high Si/Al ratios led to inefficient [Mo7O24]6‒ species and amorphous MoO3 which catalyzes the combustion reaction. Nevertheless, the use of MoCl5, MoO3 and MoO2(C5H7O2)2 led to promising activities. In catalysis, [MoO4]2‒ species are required to activate C2H6 into C2H4, while [MoxO3x+1]2‒ (x =1, 2) species catalyze the ammoniation of C2H4 and the ethylamine dehydrogenation into CH3CN. Interestingly, active catalysts could be obtained by humid impregnation and a simultaneous oxidative treatment. Such a treatment improves the dispersion state of crystalline MoO3, which activate ethane molecules. It is judicious to perform C2H6 oxidative dehydrogenation before ammoxidation since the interference between the different investigated parameters could be noted.

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Over– and low–exchanged Co/BEA catalysts: General characterization and catalytic behaviour in ethane ammoxidation

Cited by 11 publications

References 42 publications

Design of Co, Cu and Fe–BEA Zeolite Catalysts for Selective Conversion of Lactic Acid into Acrylic Acid

Design of Co, Cu and Fe–BEA Zeolite Catalysts for Selective Conversion of Lactic Acid into Acrylic Acid

Collaborative Purification of Tert-Butanol and N2O over Fe/Co-Zeolite Catalysts

Acetonitrile Synthesis via Ammoxidation: Mo/zeolites Catalysts Screening

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