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Porous Materials as Catalysts and Sorbents

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

Deadline for manuscript submissions: closed (31 July 2024) | Viewed by 15592

Special Issue Editors


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Guest Editor
Department of Inorganic and Organic Chemistry, University of Barcelona, 08028 Barcelona, Spain
Interests: gas storage; CO2, H2, and CH4 gas adsorption; gas selectivity; carbon materials, including activated carbon, graphene, and MXene; catalysis; H2 production, including photocatalysis/thermocatalysis
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Guest Editor
Department of Catalytic and Sorbent Materials Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
Interests: methane; carbon dioxide; carbon materials; adsorption; nanotubes
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Porous materials find various applications due to their diversity and the possibility of tailoring properties to specific applications. This Special Issue, “Porous Materials as Catalysts and Sorbents”, aims to publish original research and review papers on microporous and mesoporous materials, e.g., activated carbons, z mesoporous silica, zeolites, organic metal frameworks, and molecular sieves suitable for catalysis and separation applications in gaseous and liquid phases. Topics of interest include such materials’ production and modification methods, their characterization via chemical and physical methods, and theoretical modeling.

Dr. Jarosław Serafin
Prof. Dr. Beata Michalkiewicz
Guest Editors

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Keywords

  • microporous materials
  • mesoporous materials
  • composites materials
  • adsorption
  • absorption
  • catalyst
  • catalysis

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Published Papers (10 papers)

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Research

14 pages, 4432 KiB  
Article
Evaluation of Zeolite Composites by IR and NMR Spectroscopy
by Francesco Dalena, Eddy Dib, Barbara Onida, Giorgia Ferrarelli, Marco Daturi, Girolamo Giordano, Massimo Migliori and Svetlana Mintova
Molecules 2024, 29(18), 4450; https://doi.org/10.3390/molecules29184450 - 19 Sep 2024
Viewed by 788
Abstract
In this study, we assessed the quantity, strength, and acidity of zeolite composites comprising Silicalite-1 grown on ZSM-5 crystals using a combination of infrared (IR) and solid-state nuclear magnetic resonance (NMR) spectroscopy. The composites were created through the direct growth of Silicalite-1 crystals [...] Read more.
In this study, we assessed the quantity, strength, and acidity of zeolite composites comprising Silicalite-1 grown on ZSM-5 crystals using a combination of infrared (IR) and solid-state nuclear magnetic resonance (NMR) spectroscopy. The composites were created through the direct growth of Silicalite-1 crystals on ZSM-5 (P_ZSM-5), either with or without the organic structure-directing agent (OSDA) introduced into the ZSM-5 channels (samples: H_ZSM-5_Sil1 and TPA_ZSM-5_Sil1). The results revealed that Silicalite-1 grew differently when the ZSM-5 core was in the H+ form (empty pores) compared to when the OSDA was still present in the sample. This distinction was evident in the textural properties, with a decrease in the micropore surface area and an increase in the external surface area in the H_ZSM-5_Sil1 compared to the parent sample. The TPA_ZSM-5_Sil1 composite exhibited characteristics similar to the parent zeolite. These findings were further supported by 29Si NMR, which revealed a comparable local order for the parent (P_ZSM-5) and TPA_ZSM-5_Sil1 samples, along with a broadening of the Q4 peak for the H_ZSM-5_Sil1 composite. Additionally, the acid sites were preserved in the TPA_ZSM-5_Sil1 composite, while in the H+-form core, the concentration of Brønsted acid sites significantly decreased. This reduction in isolated Brønsted acid sites was further corroborated by 1H NMR. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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22 pages, 3747 KiB  
Article
Macroporous Poly(hydromethylsiloxane) Networks as Precursors to Hybrid Ceramics (Ceramers) for Deposition of Palladium Catalysts
by Jan Mrówka, Robert Kosydar, Kamil Kornaus, Janusz Partyka and Magdalena Hasik
Molecules 2024, 29(16), 3808; https://doi.org/10.3390/molecules29163808 - 11 Aug 2024
Viewed by 667
Abstract
Poly(hydromethylsiloxane) (PHMS) was cross-linked with 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (D4Vi) in water-in-oil High Internal Phase Emulsions to form macroporous materials known as polyHIPEs. It was shown that in the process of pyrolysis under Ar atmosphere at 520 °C, the obtained polyHIPEs were converted [...] Read more.
Poly(hydromethylsiloxane) (PHMS) was cross-linked with 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (D4Vi) in water-in-oil High Internal Phase Emulsions to form macroporous materials known as polyHIPEs. It was shown that in the process of pyrolysis under Ar atmosphere at 520 °C, the obtained polyHIPEs were converted to ceramers with high yields (82.8–88.0 wt.%). Structurally, the obtained ceramers were hybrid ceramics, i.e., they consisted of Si-O framework and preserved organic moieties. Macropores present in the polyHIPE precursors remained in ceramers. Ceramers contained also micro- and mesopores which resulted from the precursor’s mass loss during pyrolysis. Total pore volume and BET specific surface area related to the existence of micro- and mesopores in ceramers depended on the PHMS: D4Vi ratio applied in polyHIPE synthesis. The highest total pore volume (0.143 cm3/g) and specific surface area (344 m2/g) were reached after pyrolysis of the precursor prepared with the lowest amount of D4Vi as compared to PHMS. The composite materials obtained after deposition of PdO nanoparticles onto ceramers followed by reduction of PdO by H2 were active and selective catalysts for phenylacetylene hydrogenation to styrene. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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18 pages, 4757 KiB  
Article
Highly Porous Carbon Flakes Derived from Cellulose and Nickel Phosphide Heterostructure towards Efficient Electrocatalysis of Oxygen Evolution Reaction
by Ewa Mijowska, Karolina Pietrusewicz and Klaudia Maślana
Molecules 2024, 29(2), 352; https://doi.org/10.3390/molecules29020352 - 10 Jan 2024
Cited by 3 | Viewed by 1583
Abstract
This study delves into the pressing challenges of climate change and the escalating carbon dioxide (CO2) emissions by exploring hydrogen technology as a sustainable alternative. In particular, there is focus on nickel phosphide-based electrocatalysts, known for their promising performance in hydrogen [...] Read more.
This study delves into the pressing challenges of climate change and the escalating carbon dioxide (CO2) emissions by exploring hydrogen technology as a sustainable alternative. In particular, there is focus on nickel phosphide-based electrocatalysts, known for their promising performance in hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Therefore, here we have designed a facile strategy to deliver highly porous carbon flakes derived from cellulose fibers via carbonization at 850 °C, yielding highly porous structures and outstanding specific surface area (SSAcel_carb_850_act = 3164 m2/g) after activation. As-fabricated carbon was utilized as a support for Ni12P5 with an optimized mass ratio. Electrochemical testing revealed that the composite of Ni12P5 and carbon flakes with a ratio of 100:1, respectively, exhibited the most favorable kinetics for the oxygen evolution reaction (OER). Importantly, the durability tests of this sample demonstrated the most stable behavior and lowest potential change under high current density among the studied samples, making it a promising candidate in practical applications. Moreover, the analysis of electrocatalysts after an OER does not show any changes, indicating that the sample does not undergo undesired intermediate reactions and that unwanted products are not released, explaining its stable behavior. This provides a straightforward approach for creating a cellulose-derived composite with enhanced electroactivity and durability. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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13 pages, 2079 KiB  
Article
Influence of ZSM-5 Crystal Size on Methanol-to-Olefin (MTO) vs. Ethanol-to-Aromatics (ETA) Conversion
by Daniel Dittmann, Elif Kaya, Dennis Strassheim and Michael Dyballa
Molecules 2023, 28(24), 8046; https://doi.org/10.3390/molecules28248046 - 12 Dec 2023
Cited by 4 | Viewed by 1551
Abstract
Crystal size is a key parameter of zeolites applied as catalysts. Herein, ZSM-5 crystals with similar physicochemical and acid properties, few defects, and aluminum exclusively in tetrahedral coordination are synthesized and the influence of the crystal size on the MTO and ETA conversion [...] Read more.
Crystal size is a key parameter of zeolites applied as catalysts. Herein, ZSM-5 crystals with similar physicochemical and acid properties, few defects, and aluminum exclusively in tetrahedral coordination are synthesized and the influence of the crystal size on the MTO and ETA conversion is investigated. Short olefins are the main products of the MTO conversion, whereas larger olefins and aromatics dominate the products after ETA conversion. In the case of both feeds, an increased crystal size decreases the catalyst’s lifetime. The MTO conversion over larger ZSM-5 altered the product distribution, which was not the case for the ETA conversion. The reason is that the instantly available aromatics during ETA conversion lead to fast coking and zeolite crystals only active in the outer layers. Thus, the different reactivity of different-sized ZSM-5 is direct proof of a different conversion mechanism for both alcohols. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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13 pages, 9296 KiB  
Article
Mesoporous-Layered Double Oxide/MCM-41 Composite with Enhanced Catalytic Performance for Cyclopentanone Aldol Condensation
by Jinfan Yang, Ning Shang, Jiachen Wang and Huimin Liu
Molecules 2023, 28(23), 7920; https://doi.org/10.3390/molecules28237920 - 3 Dec 2023
Viewed by 1377
Abstract
Layered double oxides are widely employed in catalyzing the aldol condensation for producing biofuels, but its selectivity and stability need to be further improved. Herein, a novel MCM-41-supported Mg–Al-layered double oxide (LDO/MCM-41) was prepared via the in situ integration of a sol–gel process [...] Read more.
Layered double oxides are widely employed in catalyzing the aldol condensation for producing biofuels, but its selectivity and stability need to be further improved. Herein, a novel MCM-41-supported Mg–Al-layered double oxide (LDO/MCM-41) was prepared via the in situ integration of a sol–gel process and coprecipitation, followed by calcination. This composite was first employed to catalyze the self-condensation of cyclopentanone for producing high-density cycloalkane precursors. LDO/MCM-41 possessed large specific surface area, uniform pore size distribution, abundant medium basic sites and Bronsted acid sites. Compared with the bulk LDO, LDO/MCM-41 exhibited a higher selectivity for C10 and C15 oxygenates at 150 °C (93.4% vs. 84.6%). The selectivity for C15 was especially enhanced on LDO/MCM-41, which was three times greater than that on LDO. The stability test showed that naked LDO with stronger basic strength had a rapid initial activity, while it suffered an obvious deactivation due to its poor carbon balance. LDO/MCM-41 with lower basic strength had an enhanced stability even with a lower initial activity. Under the optimum conditions (50% LDO loading, 170 °C, 7 h), the cyclopentanone conversion on LDO/MCM-41 reached 77.8%, with a 60% yield of C10 and 15.2% yield of C15. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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20 pages, 2173 KiB  
Article
Removal of Methyl Red from Aqueous Solution Using Biochar Derived from Fennel Seeds
by Dorota Paluch, Aleksandra Bazan-Wozniak, Robert Wolski, Agnieszka Nosal-Wiercińska and Robert Pietrzak
Molecules 2023, 28(23), 7786; https://doi.org/10.3390/molecules28237786 - 26 Nov 2023
Cited by 8 | Viewed by 1437
Abstract
In this study, fennel (Foeniculum vulgare) seeds were used as a precursor to obtain carbon adsorbents through physical activation with carbon dioxide and chemical activation by impregnating the precursor with sodium carbonate. The physical activation involved the carbonization of the precursor [...] Read more.
In this study, fennel (Foeniculum vulgare) seeds were used as a precursor to obtain carbon adsorbents through physical activation with carbon dioxide and chemical activation by impregnating the precursor with sodium carbonate. The physical activation involved the carbonization of the precursor at a temperature of 600 °C for 60 min and activation at a temperature of 800 °C for 30 min with carbon dioxide. Chemical activation included impregnation of the precursor with sodium carbonate at a mass ratio of a precursor to activator of 1:2. The mixture was activated in a nitrogen atmosphere with a flow rate at a temperature of 700 °C for 45 min. The resulting biochar samples were washed with 5% hydrochloric acid and subsequently rinsed with boiling distilled water. The biochar adsorbents were characterized using low-temperature nitrogen adsorption–desorption isotherms, Boehm titration, and pH measurements of their aqueous extracts. The specific surface area of the obtained adsorbents ranged from 89 to 345 m2/g. Biochar adsorbents exhibit a predominance of acidic groups over basic groups on their surfaces. The sorption capacities of the obtained samples towards an aqueous solution of methyl red range from 26 to 135 mg/g. Based on adsorption studies, it was found that the adsorption of the dye on the obtained biochar materials follows a pseudo-second-order model. The Freundlich isotherm best describes the studied process, indicating the formation of a multilayer of adsorbate on the adsorbent surface. The efficacy of adsorption in aqueous solutions of methyl red was found to increase with the elevation of the process temperature. Moreover, thermodynamic studies have shown that the adsorption process is spontaneous and endothermic. Consequently, this work provides a description of the physicochemical parameters of two biochars obtained by physical and chemical activation of a little-studied precursor—fennel seeds—and studies on their potential use as adsorbents for contaminants from the aqueous phase. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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18 pages, 5137 KiB  
Article
Nanoshaped Cerium Oxide with Nickel as a Non-Noble Metal Catalyst for CO2 Thermochemical Reactions
by Jarosław Serafin and Jordi Llorca
Molecules 2023, 28(7), 2926; https://doi.org/10.3390/molecules28072926 - 24 Mar 2023
Cited by 7 | Viewed by 2246
Abstract
Four different nanoshapes of cerium dioxide have been prepared (polycrystals, rods, cubes, and octahedra) and have been decorated with different metals (Ru, Pd, Au, Pt, Cu, and Ni) by incipient wetness impregnation (IWI) and ball milling (BM) methods. After an initial analysis based [...] Read more.
Four different nanoshapes of cerium dioxide have been prepared (polycrystals, rods, cubes, and octahedra) and have been decorated with different metals (Ru, Pd, Au, Pt, Cu, and Ni) by incipient wetness impregnation (IWI) and ball milling (BM) methods. After an initial analysis based on oxygen consumption from CO2 pulse chemisorption, Ni-like metal, and two forms of CeO2 cubes and rods were selected for further research. Catalysts were characterized using the Brunauer-Emmett-Teller formula (BET), X-ray spectroscopy (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–visible spectrophotometry (UV-Vis), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR) and CO2 pulse chemisorption, and used to reduce of CO2 into CO (CO2 splitting). Adding metals to cerium dioxide enhanced the ability of CeO2 to release oxygen and concomitant reactivity toward the reduction of CO2. The effect of the metal precursor and concentration were evaluated. The highest CO2 splitting value was achieved for 2% Ni/CeO2-rods prepared by ball milling using Ni nitrate (412 µmol/gcat) and the H2 consumption (453.2 µmol/gcat) confirms the good redox ability of this catalyst. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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14 pages, 2835 KiB  
Article
Synthesis of Pillar[5]arene- and Phosphazene-Linked Porous Organic Polymers for Highly Efficient Adsorption of Uranium
by Xiaoxiao Zhao, Ziyi Liu, Shuguang Zhang, Mehdi Hassan, Chunxin Ma, Zhenzhong Liu and Weitao Gong
Molecules 2023, 28(3), 1029; https://doi.org/10.3390/molecules28031029 - 19 Jan 2023
Cited by 4 | Viewed by 2309
Abstract
It is crucial to design efficient adsorbents for uranium from natural seawater with wide adaptability, effectiveness, and environmental safety. Porous organic polymers (POPs) provide superb tunable porosity and stability among developed porous materials. In this work, two new POPs, i.e., HCCP-P5-1 and HCCP-P5-2 [...] Read more.
It is crucial to design efficient adsorbents for uranium from natural seawater with wide adaptability, effectiveness, and environmental safety. Porous organic polymers (POPs) provide superb tunable porosity and stability among developed porous materials. In this work, two new POPs, i.e., HCCP-P5-1 and HCCP-P5-2 were rationally designed and constructed by linked with macrocyclic pillar[5]arene as the monomer and hexachlorophosphate as the core via a macrocycle-to-framework strategy. Both pillar[5]arene-containing POPs exhibited high uranium adsorption capacity compared with previously reported macrocycle-free counterparts. The isothermal adsorption curves and kinetic studies showed that the adsorption of POPs on uranium was consistent with the Langmuir model and the pseudo-second-order kinetic model. Especially, HCCP-P5-1 has reached 537.81 mg/g, which is greater than most POPs that have been reported. Meanwhile, the comparison between both HCCP-P5-1 and HCCP-P5-2 can illustrate that the adsorption capacity and stability could be adjusted by the monomer ratio. This work provides a new idea for the design and construction of uranium adsorbents from macrocycle-derived POPs. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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21 pages, 5384 KiB  
Article
Impact of TiO2 Reduction and Cu Doping on Bacteria Inactivation under Artificial Solar Light Irradiation
by Piotr Rychtowski, Oliwia Paszkiewicz, Maria Carmen Román-Martínez, Maria Ángeles Lillo-Ródenas, Agata Markowska-Szczupak and Beata Tryba
Molecules 2022, 27(24), 9032; https://doi.org/10.3390/molecules27249032 - 18 Dec 2022
Cited by 2 | Viewed by 1537
Abstract
Preparation of TiO2 using the hydrothermal treatment in NH4OH solution and subsequent thermal heating at 500–700 °C in Ar was performed in order to introduce some titania surface defects. The highest amount of oxygen vacancies and Ti3+ surface defects [...] Read more.
Preparation of TiO2 using the hydrothermal treatment in NH4OH solution and subsequent thermal heating at 500–700 °C in Ar was performed in order to introduce some titania surface defects. The highest amount of oxygen vacancies and Ti3+ surface defects were observed for a sample heat-treated at 500 °C. The presence of these surface defects enhanced photocatalytic properties of titania towards the deactivation of two bacteria species, E. coli and S. epidermidis, under artificial solar lamp irradiation. Further modification of TiO2 was targeted towards the doping of Cu species. Cu doping was realized through the impregnation of the titania surface by Cu species supplied from various copper salts in an aqueous solution and the subsequent heating at 500 °C in Ar. The following precursors were used as a source of Cu: CuSO4, CuNO3 or Cu(CH3COO)2. Cu doping was performed for raw TiO2 after a hydrothermal process with and without NH4OH addition. The obtained results indicate that Cu species were deposited on the titania surface defects in the case of reduced TiO2, but on the TiO2 without NH4OH modification, Cu species were attached through the titania adsorbed hydroxyl groups. Cu doping on TiO2 increased the absorption of light in the visible range. Rapid inactivation of E. coli within 30 min was obtained for the ammonia-reduced TiO2 heated at 500 °C and TiO2 doped with Cu from CuSO4 solution. Photocatalytic deactivation of S. epidermidis was greatly enhanced through Cu doping on TiO2. Impregnation of TiO2 with CuSO4 was the most effective for inactivation of both E. coli and S. epidermidis. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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12 pages, 3279 KiB  
Article
W-SBA-15 as an Effective Catalyst for the Epoxidation of 1,5,9-Cyclododecatriene
by Marcin Kujbida, Agnieszka Wróblewska, Grzegorz Lewandowski, Piotr Miądlicki and Beata Michalkiewicz
Molecules 2022, 27(24), 8769; https://doi.org/10.3390/molecules27248769 - 10 Dec 2022
Viewed by 1243
Abstract
The results of a study on the epoxidation of 1,5,9-cyclododecatriene (CDT) on a W-SBA-15 catalyst using the batch and half-periodic methods are presented. During this study, the activity of the W-SBA-15 catalyst was compared to that of the Ti-SBA-15 catalyst, and the W-SBA-15 [...] Read more.
The results of a study on the epoxidation of 1,5,9-cyclododecatriene (CDT) on a W-SBA-15 catalyst using the batch and half-periodic methods are presented. During this study, the activity of the W-SBA-15 catalyst was compared to that of the Ti-SBA-15 catalyst, and the W-SBA-15 catalyst was found to be about 20 times more active than the Ti-SBA-15 catalyst. The highest CDT conversion so far, amounting to 86 mol%, was obtained after carrying out the 4 h epoxidation process. Conducting the studied process using the semi-batch method did not result in the significant improvement in value functions describing this process (CDT conversion and selectivity of CDT transformation to ECDD), but the fastest H2O2 dosing rate (246 µL/h) allowed us to obtain 9 mol% higher CDT conversion in comparison to the batch method. Full article
(This article belongs to the Special Issue Porous Materials as Catalysts and Sorbents)
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