Improvement of the conventional preparation methods in Co/BEA zeolites: Characterization and ethane ammoxidation

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

doi:10.1016/j.solidstatesciences.2019.04.008

Cited by 13 publications

(28 citation statements)

References 45 publications

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“…only reactions in Eqs. (10), (12) and (14) occur). However, the solid issued from ZSM-5 (Si/Al = 26) stabilized very high amounts of monomeric Mo (340 μmolg -1 ) and dimeric Mo (80 μmolg -1 ), i.e.…”

Section: Moocl 4 and Mocl 5 Issued Catalystsmentioning

confidence: 98%

“…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%

“…The S BET and S micro values do not follow a particular trend. Using Rouquerol conditions (for S BET ) and Harkns-Jura equation (for external area), suitable values were obtained with Co/BEA solids [12] . Nevertheless, remarkable values were observed in Table 5; the low S BET and V p of BEA(Mo 7 O 24 ).…”

Section: + -Zsm-5 (26) Exchanged With Moocl 4 Mocl 5 Mo(co) 6 Mmentioning

confidence: 99%

“…Over Z26(MoCl 3 ) solid, only reactions (10), (12) and (13) occur since no [Mo 7 O 24 ] 6species were formed. However, in the case of BEA(MoCl 3 ), only reactions (10), (12) and (14) take place. Seemingly, the condensation of monomeric Mo into [Mo 7 O 24 ] 6over an Al-poor zeolite, i.e.…”

Section: Mocl3 Issued Catalystsmentioning

confidence: 99%

“…However, the solid issued from ZSM-5 (Si/Al = 26) stabilized very high amounts of monomeric Mo (340 μmolg -1 ) and dimeric Mo (80 μmolg -1 ), i.e. reactions (12) and (13) are predominant.…”

Section: Moocl 4 and Mocl 5 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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Section: Moocl 4 and Mocl 5 Issued Catalystsmentioning

confidence: 98%

Section: Will the World Have Enough Ethane?mentioning

confidence: 99%

Section: + -Zsm-5 (26) Exchanged With Moocl 4 Mocl 5 Mo(co) 6 Mmentioning

confidence: 99%

Section: Mocl3 Issued Catalystsmentioning

confidence: 99%

Section: Moocl 4 and Mocl 5 Issued Catalystsmentioning

confidence: 99%

See 3 more Smart Citations

Acetonitrile Synthesis via Ammoxidation: Mo/zeolites Catalysts Screening

Ayari

Mannei

Asedegbega–Nieto

et al. 2020

Fine Chemical Engineering

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Evaluation of Co/SSZ‐13 Zeolite Catalysts Prepared by Solid‐Phase Reaction for NO‐SCR by Methane

et al. 2020

Self Cite

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Co/SSZ‐13 zeolites were prepared by heating the finely dispersed mixture of NH4‐SSZ‐13 and different cobalt salts up to 550 °C. Investigations by thermogravimetry – differential scanning calorimetry – mass spectrometry provided new insight into details of the solid‐state reaction. Formation of Co carrying hydrate melt or volatile species was shown to proceed from chloride, nitrate, or acetylacetonate Co precursor salts upon thermal treatment. This phase change allows the transport of the Co species into the zeolite pores. The reaction of the NH4+ or H+ zeolite cations and the mobile Co precursors generates vapor or gas products, readily leaving the zeolite pores, and cobalt ions in lattice positions suggesting that solid‐state ion‐exchange is the prevailing process. The obtained catalysts are of good activity and N2 selectivity in the CH4/NO‐SCR reaction. The thermal treatment of acetate or formate salts give solid intermediates that are unable to get in contact and react with the cations in the zeolite micropores. These catalysts contain mainly Co‐oxide clusters located on the outer surface of the zeolite crystallites and have poor catalytic performance.

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