molecules-logo

Journal Browser

Journal Browser

Special Issue "Zeolites and Mesoporous Materials: Properties and Applications"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Applied Chemistry".

Deadline for manuscript submissions: 15 November 2021.

Special Issue Editors

Prof. Dr. Jerzy Datka
E-Mail Website
Guest Editor
Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, Poland
Interests: IR study; quantum chemical calculations; zeolites; acid sites; transition metal cations: Cu and Co
Prof. Dr. Włodzimierz Mozgawa
E-Mail Website
Co-Guest Editor
Faculty of Materials Science and Ceramics, Department of Silicate Chemistry and Macromolecular Compounds, AGH University of Science and Technology Faculty of Material Science and Ceramics Department of Slicate Chemistry and Macromolecular Compounds, 30-059 Kraków, Poland
Interests: silicate chemistry; vibrational spectroscopy; zeolites; aluminosilicates; geopolymers; heavy metal immobilization; glassy and amorphous state; sorption processes
Dr. Dorota Rutkowska-Zbik
E-Mail Website
Co-Guest Editor
Institute of Catalysis and Surface Chemistry of the Polish Academy of Sciences, Krakow, Poland
Interests: computational chemistry; Density Functional Theory (DFT); heterogeneous catalysis; bioinorganic chemistry

Special Issue Information

Dear Colleagues,

Zeolites and mesoporous materials are important from the scientific and application research point of view. The main applications of zeolites and mesoporous materials span such fields as heterogeneous catalysts in the petrochemical and other industry; biomass upgrading and the production of fine chemicals; water softening and purification; environmental pollution control; gas separation, purification and storage; agriculture and aquaculture; medicine and biotechnology; deactivation and immobilization of hazardous substances; as well as nano-photonic and nano-sensor devices. The reasons for such versatile applications in many industrial processes are the unique properties of microporous zeolites and nanoporous materials, such as channel system, uniform pore dimensions, shape selectivity, resistance to coke formation, chemical, thermal and hydrothermal stability. Zeolites are also very interesting subject of fundamental research due to crystalline structure and of well defined structure. Therefore the structural, spectroscopic studies and quantumchemical calculations are possible for these materials.

Research reports making a relevant contribution to any of these (or related) fields will be welcome in this Special Issue of Molecules. Also welcome are reports on novel methods of synthesis, which could be needed to obtain materials in a specific form, optimize particle size, crystallinity or dimensionality for some specialized applications of zeolites. The papers concerning the structural, and spectroscopic studies as well as of quantuchemical calculations are also welcomed.

Prof. Jerzy Datka
Prof. Dr. Włodzimierz Mozgawa
Prof. Dorota Rutkowska-Zbik
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Crystalline aluminosilicates
  • zeolites
  • Mesoporous materials
  • Synthesis
  • Structure
  • Catalysis Spectroscopy (IR, NMR etc.)
  • Modeling

Published Papers (11 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
Structural Studies of Aluminated form of Zeolites—EXAFS and XRD Experiment, STEM Micrography, and DFT Modelling
Molecules 2021, 26(12), 3566; https://doi.org/10.3390/molecules26123566 - 10 Jun 2021
Viewed by 424
Abstract
In this article, the results of computational structural studies on Al-containing zeolites, via periodic DFT + D modelling and FDM (Finite Difference Method) to solve the Schrödinger equation (FDMNES) for XAS simulations, corroborated by EXAFS (Extended X-ray Absorption Fine Structure) spectroscopy and PXRD [...] Read more.
In this article, the results of computational structural studies on Al-containing zeolites, via periodic DFT + D modelling and FDM (Finite Difference Method) to solve the Schrödinger equation (FDMNES) for XAS simulations, corroborated by EXAFS (Extended X-ray Absorption Fine Structure) spectroscopy and PXRD (powder X-ray diffractometry), are presented. The applicability of Radial Distribution Function (RDF) to screen out the postulated zeolite structure is also discussed. The structural conclusions are further verified by HR-TEM imaging. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Graphical abstract

Article
In Search of Factors Determining Activity of Co3O4 Nanoparticles Dispersed in Partially Exfoliated Montmorillonite Structure
Molecules 2021, 26(11), 3288; https://doi.org/10.3390/molecules26113288 - 29 May 2021
Viewed by 516
Abstract
The paper discusses a formation of Mt–PAA composite containing a natural montmorillonite structure partially exfoliated by poly(acrylic acid) introduced through intercalation polymerization of acrylic acid. Mt–PAA was subsequently modified by controlled adsorption of Co2+ ions. The presence of aluminosilicate packets (clay) and [...] Read more.
The paper discusses a formation of Mt–PAA composite containing a natural montmorillonite structure partially exfoliated by poly(acrylic acid) introduced through intercalation polymerization of acrylic acid. Mt–PAA was subsequently modified by controlled adsorption of Co2+ ions. The presence of aluminosilicate packets (clay) and carboxyl groups (hydrogel) led to the deposition of significant amounts of Co2+ ions, which after calcination formed the Co3O4 spinel particles. The conditions of the Co2+ ions’ deposition (pH, volume and concentration of Co(NO3)2 solution, as well as a type of pH-controlling agent) were widely varied. Physicochemical characterization of the prepared materials (including X-ray fluorescence (XRF), X-ray powder diffraction (XRD), low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (H2-TPR)) revealed that the modification conditions strongly influenced the content as well as the distribution of the Co3O4 active phase, tuning its reducibility. The latter parameter was, in turn, very important from the point of view of catalytic activity in the combustion of aromatic volatile organic compounds (VOCs) following the Mars–van Krevelen mechanism. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
A Comparative Analysis of In Vitro Toxicity of Synthetic Zeolites on IMR-90 Human Lung Fibroblast Cells
Molecules 2021, 26(11), 3194; https://doi.org/10.3390/molecules26113194 - 26 May 2021
Viewed by 506
Abstract
Broad industrial application of zeolites increases the opportunity of inhalation. However, the potential impact of different types and compositions of zeolite on cytotoxicity is still unknown. Four types of synthetic zeolites have been prepared for assessing the effect on lung fibroblast: two zeolite [...] Read more.
Broad industrial application of zeolites increases the opportunity of inhalation. However, the potential impact of different types and compositions of zeolite on cytotoxicity is still unknown. Four types of synthetic zeolites have been prepared for assessing the effect on lung fibroblast: two zeolite L (LTL-R and LTL-D), ZSM-5 (MFI-S), and faujasite (FAU-S). The cytotoxicity of zeolites on human lung fibroblast (IMR-90) was assessed using WST1 cell proliferation assay, mitochondrial function, membrane leakage of lactate dehydrogenase, reduced glutathione levels, and mitochondrial membrane potential were assessed under control. Intracellular changes were examined using transmission electron microscopy (TEM). Toxicity-related gene expressions were evaluated by PCR array. The result showed significantly higher toxicity in IMR-90 cells with FAU-S than LTL-R, LTL-D and MFI-S exposure. TEM showed FAU-S, spheroidal zeolite with a low Si/Al ratio, was readily internalized forming numerous phagosomes in IMR-90 cells, while the largest and disc-shaped zeolites showed the lowest toxicity and were located in submembranous phagosomes in IMR-90 cells. Differential expression of TNF related genes was detected using PCR arrays and confirmed using qRT-PCR analysis of selected genes. Collectively, the exposure of different zeolites shows different toxicity on IMR-90 cells. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
Oxidation of Ethanol in Cu-Faujasites Studied by IR Spectroscopy
Molecules 2021, 26(9), 2669; https://doi.org/10.3390/molecules26092669 - 02 May 2021
Viewed by 581
Abstract
In this study, IR studies of the coadsorption of ethanol and CO on Cu+ cations evidenced the transfer of electrons from ethanol to Cu+, which caused the lowering of the frequency of the band attributed to CO bonded to the [...] Read more.
In this study, IR studies of the coadsorption of ethanol and CO on Cu+ cations evidenced the transfer of electrons from ethanol to Cu+, which caused the lowering of the frequency of the band attributed to CO bonded to the same Cu+ cation due to the more effective π back donation of d electrons of Cu to antibonding π* orbitals of CO. The reaction of ethanol with acid sites in zeolite HFAU above 370 K produced water and ethane, polymerizing to polyethylene. Ethanol adsorbed on zeolite Cu(2)HFAU containing acid sites and Cu+exch also produced ethene, but in this case, the ethene was bonded to Cu+ and did not polymerize. C=C stretching, which is IR non-active in the free ethene molecule, became IR active, and a weak IR band at 1538 cm−1 was present. The reaction of ethanol above 370 K in Cu(5)NaFAU zeolite (containing small amounts of Cu+exch and bigger amounts of Cu+ox, Cu2+exch and CuO) produced acetaldehyde, which was further oxidized to the acetate species (CH3COO). As oxygen was not supplied, the donors of oxygen were the Cu species present in our zeolite. The CO and NO adsorption experiments performed in Cu-zeolite before and after ethanol reaction evidenced that both Cu+ox and Cu2+ (Cu2+exch and CuO) were consumed by the ethanol oxidation reaction. The studies of the considered reaction of bulk CuO and Cu2O as well as zeolites, in which the contribution of Cu+ox species was reduced by various treatments, suggest that ethanol was oxidized to acetaldehyde by Cu2+ox (the role of Cu+ox could not be elucidated), but Cu+ox was the oxygen donor in the acetate formation. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
On the Role of Protonic Acid Sites in Cu Loaded FAU31 Zeolite as a Catalyst for the Catalytic Transformation of Furfural to Furan
Molecules 2021, 26(7), 2015; https://doi.org/10.3390/molecules26072015 - 01 Apr 2021
Viewed by 425
Abstract
The aim of the present paper is to study the speciation and the role of different active site types (copper species and Brønsted acid sites) in the direct synthesis of furan from furfural catalyzed by copper-exchanged FAU31 zeolite. Four series of samples were [...] Read more.
The aim of the present paper is to study the speciation and the role of different active site types (copper species and Brønsted acid sites) in the direct synthesis of furan from furfural catalyzed by copper-exchanged FAU31 zeolite. Four series of samples were prepared by using different conditions of post-synthesis treatment, which exhibit none, one or two types of active sites. The catalysts were characterized by XRD, low-temperature sorption of nitrogen, SEM, H2-TPR, NMR and by means of IR spectroscopy with ammonia and CO sorption as probe molecules to assess the types of active sites. All catalyst underwent catalytic tests. The performed experiments allowed to propose the relation between the kind of active centers (Cu or Brønsted acid sites) and the type of detected products (2-metylfuran and furan) obtained in the studied reaction. It was found that the production of 2-methylfuran (in trace amounts) is determined by the presence of the redox-type centers, while the protonic acid sites are mainly responsible for the furan production and catalytic activity in the whole temperature range. All studied catalysts revealed very high susceptibility to coking due to polymerization of furfural. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
Vibrational Spectra of Zeolite Y as a Function of Ion Exchange
Molecules 2021, 26(2), 342; https://doi.org/10.3390/molecules26020342 - 11 Jan 2021
Viewed by 536
Abstract
Zeolite Y is one of the earliest known and most widely used synthetic zeolites. Many experimental investigations verify the valuable ion exchange capability of this zeolite. In this study, we assessed the effects of ion exchange on its vibrational spectra. We applied classical [...] Read more.
Zeolite Y is one of the earliest known and most widely used synthetic zeolites. Many experimental investigations verify the valuable ion exchange capability of this zeolite. In this study, we assessed the effects of ion exchange on its vibrational spectra. We applied classical lattice dynamics methods for IR and Raman intensity calculations. Computed spectra of optimized zeolite Y structures with different cations were compared with experimental data. The spectra obtained in this study are in agreement with previous experimental and computational studies on zeolites from the faujasite group. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
Lights and Shadows of Gold Introduction into Beta Zeolite
Molecules 2020, 25(24), 5781; https://doi.org/10.3390/molecules25245781 - 08 Dec 2020
Cited by 1 | Viewed by 580
Abstract
Four different methods for gold deposition on Beta zeolite, namely impregnation, ion-exchange, deposition-reduction, and grafting on (3-aminopropyl)trimethoxysilane functionalized support, were applied to investigate their influence on textural/structural changes in the zeolite support and its surface acidity. The as-prepared materials were fully characterized by [...] Read more.
Four different methods for gold deposition on Beta zeolite, namely impregnation, ion-exchange, deposition-reduction, and grafting on (3-aminopropyl)trimethoxysilane functionalized support, were applied to investigate their influence on textural/structural changes in the zeolite support and its surface acidity. The as-prepared materials were fully characterized by XRD, N2 physisorption, ICP-OES, XPS, TEM, and pyridine adsorption. The obtained results indicated that bifunctional redox–acidic materials prepared within this work were characterized not only by different gold loading and gold particle size, but also different textural parameters and acidity. All these features were strongly affected by the procedure applied for gold deposition. The introduction of Au into Beta zeolite by ion exchange caused a significant decrease in the Si/Al ratio in the zeolite framework. The size of Au particles determined the textural parameters of the zeolite and the number of Lewis acid sites (LAS). The Brønsted acid sites (BAS) number was decreased if (3-aminopropyl)trimethoxysilane or NaBH4 were used in the procedure of gold deposition. The highest BAS/LAS ratio was achieved for the sample prepared by ion exchange in the ammonium form of Beta zeolite. The presented results permit making a proper choice of the gold modification procedure for the preparation of bifunctional (redox–acidic) materials, addressed to a desired application. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Graphical abstract

Article
Catalytic Performance of Spherical MCM-41 Modified with Copper and Iron as Catalysts of NH3-SCR Process
Molecules 2020, 25(23), 5651; https://doi.org/10.3390/molecules25235651 - 30 Nov 2020
Viewed by 475
Abstract
Spherical MCM-41 with various copper and iron loadings was prepared by surfactant directed co-condensation method. The obtained samples were characterized with respect to their structure (X-ray diffraction, XRD), texture (N2 sorption), morphology (scanning electron microscopy, SEM), chemical composition (inductively coupled plasma optical [...] Read more.
Spherical MCM-41 with various copper and iron loadings was prepared by surfactant directed co-condensation method. The obtained samples were characterized with respect to their structure (X-ray diffraction, XRD), texture (N2 sorption), morphology (scanning electron microscopy, SEM), chemical composition (inductively coupled plasma optical emission spectrometry, ICP-OES), surface acidity (temperature programmed desorption of ammonia, NH3-TPD), form, and aggregation of iron and copper species (diffuse reflectance UV-Vis spectroscopy, UV-Vis DRS) as well as their reducibility (temperature programmed reduction with hydrogen, H2-TPR). The spherical MCM-41 samples modified with transition metals were tested as catalysts of selective catalytic reduction of NO with ammonia (NH3-SCR). Copper containing catalysts presented high catalytic activity at low-temperature NH3-SCR with a very high selectivity to nitrogen, which is desired reaction products. Similar results were obtained for iron containing catalysts, however in this case the loadings and forms of iron incorporated into silica samples very strongly influenced catalytic performance of the studied samples. The efficiency of the NH3-SCR process at higher temperatures was significantly limited by the side reaction of direct ammonia oxidation. The reactivity of ammonia molecules chemisorbed on the catalysts surface in NO reduction (NH3-SCR) and their selective oxidation (NH3-SCO) was verified by temperature-programmed surface reactions. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
Detemplated and Pillared 2-Dimensional Zeolite ZSM-55 with Ferrierite Layer Topology as a Carrier for Drugs
Molecules 2020, 25(15), 3501; https://doi.org/10.3390/molecules25153501 - 31 Jul 2020
Cited by 1 | Viewed by 758
Abstract
The present studies were conducted to show the potential of 2D zeolites as effective and non-toxic carriers of drugs. Layered zeolites exhibit adjustable interlayer porosity which can be exploited for controlled drug delivery allowing detailed investigation of the drug release because the structure [...] Read more.
The present studies were conducted to show the potential of 2D zeolites as effective and non-toxic carriers of drugs. Layered zeolites exhibit adjustable interlayer porosity which can be exploited for controlled drug delivery allowing detailed investigation of the drug release because the structure of the carrier is known exactly. This study was conducted with model drugs ciprofloxacin and piracetam, and ZSM-55 with ca 1 nm thick layers, in detemplated and pillared forms. The release profiles differed from the commercial, crystalline forms of drugs—the release rate increased for ciprofloxacin and decreased for piracetam. To understand the dissolution mechanisms the release data were fitted to Korsmeyer-Peppas equation, showing Fickian (for pillared) and anomalous (for detemplated sample) transport. FT-IR studies showed that strong interaction carrier-drug may be responsible for the modified, slowed down release of piracetam while better solubility and faster release of ciprofloxacin was attributed to formation of the protonated form resulting in weaker interaction with the zeolite than in the pure crystalline form. Two independent tests on L929 mice fibroblasts (ToxiLight and PrestoBlue) showed that ZSM-55, in moderate concentrations may be safely used as a carrier of drug molecules, not having negative effect on the cells viability or proliferation rate. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Figure 1

Article
Opening up ZSM-5 Hierarchical Zeolite’s Porosity through Sequential Treatments for Improved Low-Density Polyethylene Cracking
Molecules 2020, 25(12), 2878; https://doi.org/10.3390/molecules25122878 - 22 Jun 2020
Cited by 1 | Viewed by 755
Abstract
An adequately tuned acid wash of hierarchical ZSM-5 zeolites offers a levelling up in the catalytic cracking of low-density polyethylene. Identification of crucial and limiting factors governing the activity of the zeolite was extended with studies about the accessibility of acid sites, nature [...] Read more.
An adequately tuned acid wash of hierarchical ZSM-5 zeolites offers a levelling up in the catalytic cracking of low-density polyethylene. Identification of crucial and limiting factors governing the activity of the zeolite was extended with studies about the accessibility of acid sites, nature of the realuminated layer and role of Lewis acid sites. The sequential treatment of a ZSM-5 zeolite offered enhanced activity in low-density polyethylene (LDPE) cracking at low and high conversions, as confirmed by a decrease in the temperatures needed to reach 20% and 80% conversion (T20 and T80, respectively). A linear dependence of the T80 on the coupled IHF (indexed hierarchy factor) and AFB (accessibility factor) highlighted the importance of the textural and acidic parameters in the catalytic cracking of LDPE. Operando FT-IR-GC studies confirmed a higher fraction of short-chain hydrocarbons (C3–C5) in the product distribution of hierarchical catalysts resulting from the effective polymer cracking in easily accessible pores. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Graphical abstract

Review

Jump to: Research

Review
Zeolites at the Molecular Level: What Can Be Learned from Molecular Modeling
Molecules 2021, 26(6), 1511; https://doi.org/10.3390/molecules26061511 - 10 Mar 2021
Viewed by 908
Abstract
This review puts the development of molecular modeling methods in the context of their applications to zeolitic active sites. We attempt to highlight the utmost necessity of close cooperation between theory and experiment, resulting both in advances in computational methods and in progress [...] Read more.
This review puts the development of molecular modeling methods in the context of their applications to zeolitic active sites. We attempt to highlight the utmost necessity of close cooperation between theory and experiment, resulting both in advances in computational methods and in progress in experimental techniques. Full article
(This article belongs to the Special Issue Zeolites and Mesoporous Materials: Properties and Applications)
Show Figures

Graphical abstract

Back to TopTop