Vibrational Spectra of Zeolite Y as a Function of Ion Exchange

Król, Magdalena; Koleżyński, Andrzej; Mozgawa, W.

doi:10.3390/molecules26020342

Cited by 22 publications

(9 citation statements)

References 34 publications

(47 reference statements)

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“…The Si/Al ratios for the initial, 5th, and 10th reuse catalysts of XZ-Na and XZ-K measured by EDX were 1.40, 1.39, 1.38, and 1.40, 1.40, 1.41, respectively (Figure S5 and Table S1). The IR peak position corresponding to Si/Al was obtained consistent with the previously reported experimental results and theoretical calculations [34][35][36]. Therefore, it appears that the rather large shift of the IR peak in reused XZ-K catalysts is due to the difference of mesopores rather than the altered the Si/Al ratio.…”

Section: Resultssupporting

confidence: 88%

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Tuning the Catalytic Activity of Recyclable Heterogeneous Catalysts for the Direct Etherification Reaction of Glycerol Using Antagonistic Additives

et al. 2022

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Using zeolite as a heterogeneous catalyst, the reaction conditions were optimized to increase the yield and selectivity of diglycerol (DG) and triglycerol (TG) in the direct etherification reaction of glycerol. By the addition of weakly acidic alkali metal-based inorganic salts (NaHSO4 and KHSO4), the selectivities and yields of DG and TG increased. Although the conversion of glycerol was lowered due to the role of the additive as an inhibitor, the reaction conditions were optimized by controlling the amounts and reaction times of the additives to increase the yields of DG and TG. Under the optimized condition, the glycerol conversion was as high as 85.4%, and the highest yields of DG and TG were observed as 54.1% and 21.3%, respectively. The recyclability of the catalysts was much enhanced by the influence of the additives suppressing the formation of oligomers.

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Section: Resultssupporting

confidence: 88%

“…S1). The IR peak position corresponding to Si/Al was obtained consistent with the previously reported experimental results and theoretical calculations [34][35][36]. Therefore, it appears that the rather large shift of the IR peak in reused XZ-K catalysts is due to the difference of mesopores rather than the altered the Si/Al ratio.…”

Section: Resultssupporting

confidence: 88%

Tuning the Catalytic Activity of Recyclable Heterogeneous Catalysts for the Direct Etherification Reaction of Glycerol Using Antagonistic Additives

et al. 2022

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“…The higher the Si/Al ratio, the more the unit cell's dimensions were increased and the more uniform the structure. Both effects were observed in experimental studies [41,42].…”

Section: Optimized X-and Y-type Faujasite Zeolitesmentioning

confidence: 66%

“…The higher the Si/Al ratio, the more the unit cell's dimensions were increased and the more uniform the structure. Both effects were observed in experimental studies [41,42]. The diameter of the central pore was considered as the length between two oxygen atoms located at opposite extremes of the pore of the optimized framework cell, as shown in Figure 5.…”

Section: Optimized X-and Y-type Faujasite Zeolitesmentioning

confidence: 98%

Computational Study of the Adsorption of Phosphates as Wastewater Pollutant Molecules on Faujasites

2021

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The adsorption of sodium dihydrogen phosphate (NaH2PO4) onto X- and Y-type faujasite zeolites was computationally studied using the Density Functional Theory (DFT) method. The structures were modeled using the Materials Studio software. The Si/Al ratios for the X- and Y-type zeolite models were 1.2 and 2.5, respectively. The central pore of the zeolite provided a more favorable coordination for adsorbing NaH2PO4. Full molecular optimization and adsorption energy calculations were performed using the VASP code. The adsorption was more effective on zeolite Y, with an adsorption energy of 161 kJ/mol, compared to the zeolite X system, with an adsorption energy of 31.64 kJ/mol. This calculated value for X-type faujasite was found in the interval of the adsorption energy of H2PO4− on hydrated Fe oxide (94.4 kJ/mol) and modified polyether sulfone (22.5 kJ/mol), and the calculated adsorption energy of the molecule on Y-type faujasite coincides with the reported value for this adsorbate on Mg/Ca-modified biochar structures. The molecular conformations of the adsorbate on the two studied models are very different, so the difference between the adsorption energy values of each type of zeolite model is comprehensible. On the one hand, the oxygen atoms of the molecule formed a bidentate complex with the hydrogen atoms of the pore in the X-type faujasite model, and the O-H distance was 1.5 Ǻ. On the other hand, an adsorbed oxygen atom of the phosphate was placed on a hydrogen atom at site II of the Y-type faujasite zeolite, and two of the hydrogen atoms of the phosphate were placed on the oxygen atoms. The Bader analysis results indicated that the negative charge of the phosphate anions was delocalized on the zeolites protons. The hydroxy groups of the phosphate form bonds between their hydrogen atoms and the oxygen atoms of the zeolite porous structure; therefore, we concluded that these sites have an alkaline character. The aim of this study was to include a computational analysis of possible phosphate adsorption mechanisms in faujasite zeolites that can be confirmed by experimental tests, and hence contribute to the generation of new technologies for capturing pollutant molecules in wastewater. The results are in agreement with the experimental information concerning the influence of pH on the adsorption activity of phosphate adsorption on zeolites.

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“…Zeolites rich in Al are attracted towards polar molecules (H 2 O) such as water, while zeolites rich in Si are attracted towards nonpolar molecules [24]. Due to all these above-mentioned features, zeolites have been widely used in wastewater treatment as an adsorbent [25], in agriculture as fertilizers [26] and as ion exchangers [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

A Short Review on the Utilization of Incense Sticks Ash as an Emerging and Overlooked Material for the Synthesis of Zeolites

Yadav¹,

Choudhary

Tirth

et al. 2021

Crystals

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The traditional hydrothermal synthesis methods are mainly performed under batch operation, which generally takes few days to weeks to yield a zeolite with the desired properties and structure. The zeolites are the backbone of the petrochemical and wastewater industries due to their importance. The commercial methods for zeolite synthesis are expensive, laborious and energy intensive. Among waste products, incense sticks ash is a compound of aluminosilicates and could act as a potential candidate for the synthesis of zeolites for daily needs in these industries. Incense sticks ash is the byproduct of religious places and houses and is rich in Ca, Mg, Al and Si. As a result, incense sticks ash can be proven to be a potential candidate for the formation of calcium-rich zeolites. The formation of zeolites from incense sticks ash is an economical, reliable and eco-friendly method. The application of incense sticks ash for zeolite synthesis can also minimize the problem related to its disposal in the water bodies, which will also minimize the solid waste in countries where it is considered sacred and generated in tons every day.

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Vibrational Spectra of Zeolite Y as a Function of Ion Exchange

Cited by 22 publications

References 34 publications

Tuning the Catalytic Activity of Recyclable Heterogeneous Catalysts for the Direct Etherification Reaction of Glycerol Using Antagonistic Additives

Tuning the Catalytic Activity of Recyclable Heterogeneous Catalysts for the Direct Etherification Reaction of Glycerol Using Antagonistic Additives

Computational Study of the Adsorption of Phosphates as Wastewater Pollutant Molecules on Faujasites

A Short Review on the Utilization of Incense Sticks Ash as an Emerging and Overlooked Material for the Synthesis of Zeolites

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