An FT-Raman study of solid-state ion exchange in zeolites

Huang, Yining; Paroli, Ralph M.; Delgado, Ana H.; Richardson, Troy A.

doi:10.1016/s1386-1425(98)00035-3

Cited by 13 publications

(15 citation statements)

References 7 publications

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“…The bands around 500 cm −1 are associated to zeolites with even-number rings [54], in this case W zeolite structure possess 8-member rings. The variation in the frequency of the bands is due to the nature of cations [55]. Additionally to these bands, in Fe-modified W zeolite new bands at 615 and 671 cm −1 were detected, they could be associated to the presence of the iron in the zeolite, considering that the only difference between the pristine and the modified zeolites is the chemical composition.…”

Section: Characterization Techniquesmentioning

confidence: 90%

“…The Raman spectra (Figure 1b) of the pristine and the modified W zeolites shows the characteristic peaks of the zeolitic materials. The most intense bands correspond to the region of 300-600 cm −1 [54,55]. The band [54] at 295 cm −1 is associated to motion of an oxygen atom in a perpendicular plane to T-O-T bonds (T = Si or Al) while the bands at 414 and 423 cm −1 corresponding to vibration mode of tetrahedral in the network [56].…”

Section: Characterization Techniquesmentioning

confidence: 99%

“…Water 2019, 11, 281 6 of 17 characteristic peaks of the zeolitic materials. The most intense bands correspond to the region of 300-600 cm −1 [54,55].The band [54] at 295 cm −1 is associated to motion of an oxygen atom in a perpendicular plane to T-O-T bonds (T = Si or Al) while the bands at 414 and 423 cm −1 corresponding to vibration mode of tetrahedral in the network [56]. The bands around 500 cm −1 are associated to zeolites with even-number rings [54], in this case W zeolite structure possess 8-member rings.…”

Section: Fe-modified W Zeolite Characterizationmentioning

confidence: 99%

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Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite

Medina-Ramírez

Gamero‐Melo²,

Ruiz-Camacho

et al. 2019

Water

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The high toxicity of arsenite and the difficulty to remove it is one of the main challenges for water treatment. In the present work the surface of a low cost zeolite was modified by chemical treatment with a ferrous chloride to enhance its arsenite adsorption capacity. The effect of pH, ions coexistence, concentration, temperature and dosage was studied on the adsorption process. Additionally, the Fe-modified W zeolite was aged by an accelerated procedure and the regeneration of the exhausted zeolite was demonstrated. The Fe-modified W zeolite was stable in the pH range of 3 to 8 and no detriment to its arsenite removal capacity was observed in the presence of coexisting ions commonly found in underground water. The studies showed that the adsorption of As (III) on Fe-modified W zeolite is a feasible, spontaneous and endothermic process and it takes place by chemical bonding. The exhausting process proved the adsorption of 0.20 mg g−1 of As (III) by the Fe-modified W zeolite and this withstand at least five aging cycles without significant changes of its arsenite adsorption capacity. Fe-modified W zeolite prepared from fly ash might be a green and low-cost alternative for removal of As (III) from groundwater.

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Section: Characterization Techniquesmentioning

confidence: 90%

Section: Characterization Techniquesmentioning

confidence: 99%

Section: Fe-modified W Zeolite Characterizationmentioning

confidence: 99%

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Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite

Medina-Ramírez

Gamero‐Melo²,

Ruiz-Camacho

et al. 2019

Water

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“…4 presents the Raman spectra of CrNaY support and the homologous catalysts prepared with the three different ligands. Although the spectra are dominated by the intrinsic background fluorescence of calcined zeolitic samples [38], it is possible to identify peaks at 1360 and 942 cm À1 in [CrL 1a ]NaY and [CrL 1b ]NaY. The spectrum of [CrL 1c ]NaY is similar to the one of CrNaY.…”

Section: Preparation and Characterization Of The Heterogeneous Cr-faumentioning

confidence: 94%

Oxidation of cyclohexanol and cyclohexene with triazenido complexes of chromium immobilized in biosorption FAU supports

Figueiredo

Silva

Kuźniarska‐Biernacka

et al. 2014

Chemical Engineering Journal

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“…Vibrational spectroscopy is one of the most important experimental methods used in studies of zeolite structures [3][4][5][6][7][8][9][10]. It allows various frameworks to be identified and structural deformation to be specified using the envelope and integral intensities of bands in the pseudolattice region of the spectrum (linked to characteristic ring vibrations [11]).…”

Section: Introductionmentioning

confidence: 99%

Periodic model of an LTA framework

2015

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Zeolites are a group of microporous aluminosilicate frameworks with numerous applications in, for example, catalysis and ion-exchange and sorption processes. One of the most important tools for analyzing the properties of zeolite structures is vibrational spectroscopy. However, the complexity of these structures often leads to difficulties when attempting to interpret the resulting spectra, so an additional complementary tool is required: computational methods. The aim of this study was to formulate a simplified periodic model of an LTA framework containing alkali metal cations (either Li(+), Na(+), K(+), Rb(+), or Cs(+)) and to perform a set of ab initio calculations aimed at assessing the influence of these cations on the properties of the vibrational spectra of the LTA framework. Additionally, chemical bonding was analyzed by means of electron density topology analysis. Results obtained were compared with experimental spectra for alkali metal forms of zeolite A. It was found that the vibrational spectra obtained using the proposed model agree well with the corresponding experimentally derived spectra, meaning that the model can be used to analyze real spectra in detail.

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An FT-Raman study of solid-state ion exchange in zeolites

Cited by 13 publications

References 7 publications

Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite

Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite

Oxidation of cyclohexanol and cyclohexene with triazenido complexes of chromium immobilized in biosorption FAU supports

Periodic model of an LTA framework

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