Influence of the cobalt salt precursors on the cobalt speciation and catalytic properties of H-ZSM-5 modified with cobalt by solid-state ion exchange reaction

Mhamdi, Mourad; Khaddar-Zine, Sihem; Ghorbel, Abdelhamid

doi:10.1016/j.apcata.2008.12.036

Cited by 83 publications

(51 citation statements)

References 53 publications

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“…It was argued that it is highly improbable that bare Co 3+ ions could neutralize three distant negative charges of the zeolite having high framework Si to Al ratio (>15). The oxygen-carrying Co 3+ was expected to get reduced at lower temperature than the Co 2+ ions [10,11,25,27,28]. The H 2 -TPR results, however, showed that our Co IE ,H-ZSM-5 sample contains only a minor amount of cobalt species reducible below 1073 K ( (2) and (3)) proceed on these samples.…”

Section: Catalytic Resultsmentioning

confidence: 65%

“…The Co-species in the Co-form zeolites are quite well described [3,11,[22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

“…1 Table 2). The Co 2+ cations of zeolites were shown to become reduced only over about 1073 K [10,11,25,27,28]. The low intensity peaks in between 723 and 823 K indicate that some Cooxo species were also formed during preparation of the ion-exchanged Co-zeolite samples, which were most probably located within the zeolite pores [28].…”

Section: H 2 -Tprmentioning

confidence: 99%

See 2 more Smart Citations

Mechanism of NO-SCR by methane over Co,H-ZSM-5 and Co,H-mordenite catalysts

Lónyi

Solt

Pászti

et al. 2014

Applied Catalysis B: Environmental

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Section: Catalytic Resultsmentioning

confidence: 65%

“…The Co-species in the Co-form zeolites are quite well described [3,11,[22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism of NO-SCR by methane over Co,H-ZSM-5 and Co,H-mordenite catalysts

Lónyi

Solt

Pászti

et al. 2014

Applied Catalysis B: Environmental

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show abstract

“…Since previous research has focused on catalysis itself and location and state of Co (Khodakov et al, 2007;Park et al, 2004;Mhamdi et al, 2009;Dědečk and Wichterlová, 1999;Dědečk et al, 2000;Dědečk et al, 2002) using mainly spectroscopic techniques, the ion exchange isotherms have hardly been studied (Guczi and Kiricsi, 1999). Therefore, this work aimed to determine the maximum content of cobalt ions that can be incorporated into the protonic zeolites Beta, Mordenite, USY and ZSM-5 by ion exchange.…”

Section: Introductionmentioning

confidence: 99%

Determination of the maximum retention of cobalt by ion exchange in h-zeolites

Zola

Barros

Sousa-Aguiar

et al. 2012

Braz. J. Chem. Eng.

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-This work aimed to determine the maximum content of cobalt that can be incorporated by ion exchange in zeolites H-USY, H-Beta, H-Mordenite, and H-ZSM-5. To reach this goal, batch isotherms at 75ºC were constructed after addition of zeolite samples in flasks filled with cobalt nitrate solution. The equilibrium data were fitted to Langmuir, Freundlich, and Tóth adsorption isotherm models. Langmuir was the best model for zeolites H-Beta, H-Mordenite, and H-ZSM-5, whereas experimental data for H-USY were better fitted to the Freundlich isotherm model. From the isotherms, it was possible to determine the maximum cobalt exchange level (q max ) that can be incorporated in each zeolite through ion exchange. In this sense, H-USY presented the highest q max value (2.40 meq/g zeol ), while H-ZSM-5 showed the lowest one (0.64 meq/g zeol ).These results also show the influence of the zeolite framework related to the channel system, pore opening, presence of cavities and secondary porosity and SiO 2 /Al 2 O 3 ratio (SAR) on the maximum capacity and behavior of cobalt ion exchange in protonic zeolites.

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“…5, and the amounts of NH 3 desorbed from per unit area of catalysts are calculated in Table 4. The desorption peak of NH 4+ bound to weak Brφnsted acid sites is detected at low temperature, whereas the peak at high temperature is thought to be caused by NH 3 desorption from medium acid sites (Mhamdi et al, 2009;Shen et al, 2013). We could notice that the profile of …”

Section: Nh 3 -Tpdmentioning

confidence: 99%

Selective Catalytic Reduction of NO over Cu-Mn/OMC Catalysts: Effect of Preparation Method

Cao

Zhu

et al. 2017

Aerosol Air Qual. Res.

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Ordered mesoporous carbon (OMC) was used as support for CuO x and MnO x , and the effects of preparation method on selective catalytic reduction (SCR) of NO with NH 3 were investigated. The Cu-Mn/OMC prepared by solvent evaporation-induced self-assembly method, named as self-assembly synthesis (S), exhibited higher NO conversion and N 2 selectivity than the catalyst prepared by ultrasound-assisted impregnation (I) or mechanical mixing (M). The structural and surface properties of catalysts were characterized by various techniques. XRD and TEM results showed good dispersion of active phases on Cu-Mn/OMC(S). XPS analysis suggested that the surface of Cu-Mn/OMC(S) had the maximum amount of O-C=O groups and chemisorbed O. The strongest acidity and largest amount of oxidative species were further illustrated by NH 3 -TPD and H 2 -TPR profiles, which were consistent with the XPS results. Accordingly, these favorable properties may be the main reasons for the outstanding performance of Cu-Mn/OMC(S) in NH 3 -SCR reaction. Thus, selfassembly synthesis can be considered an effective method for the preparation of OMC-supported catalysts.

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Influence of the cobalt salt precursors on the cobalt speciation and catalytic properties of H-ZSM-5 modified with cobalt by solid-state ion exchange reaction

Cited by 83 publications

References 53 publications

Mechanism of NO-SCR by methane over Co,H-ZSM-5 and Co,H-mordenite catalysts

Mechanism of NO-SCR by methane over Co,H-ZSM-5 and Co,H-mordenite catalysts

Determination of the maximum retention of cobalt by ion exchange in h-zeolites

Selective Catalytic Reduction of NO over Cu-Mn/OMC Catalysts: Effect of Preparation Method

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