Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
6.8
3.8
Journals
Catalysts
Special Issues
Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes
share announcement

Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Catalytic Materials".

Deadline for manuscript submissions: closed (30 June 2023) | Viewed by 35838

Special Issue Editors

Prof. Dr. Roman Dziembaj

E-Mail Website
Guest Editor
Jagiellonian University in Kraków, Faculty of Chemistry, Chemical Technology Department, (Emeritus), Gronostajowa 2, 30-387 Kraków, Poland
Interests: transition metal oxides as catalytic and energy storage materials; nano-structured catalysts—synthesis, activation, and deactivation; functionalization of carbon and inorganic porous materials; green chemistry processes; environmental catalysis
Prof. Dr. Lucjan Chmielarz

E-Mail Website
Guest Editor
Faculty of Chemistry, Jagiellonian University in Kraków, Gronostajowa 2, 30-387 Kraków, Poland
Interests: heterogeneous catalysis for environmental applications; zeolites and their functionalization for catalysis and adsorption; clay minerals—intercalation and acid modifications; mesoporous silica materials for catalytic applications; layered double hydroxides and their calcined forms for environmental applications
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Nano-porous materials, especially those with ordered and well defined porous structures, have been known as catalytic supports and catalysts of various chemical reactions, including industrial chemical processes and pollution control technologies. Recent trends in studies of such nano-porous materials for catalysis are focused, among others, on the synthesis of catalysts with dual micro-mesoporous porosity, crystalline mesoporous aluminosilicates, as well as deposition of catalytically active components in uniform and stable forms. Progress in these studies has opened new perspectives for more effective catalytic systems with improved activity, selectivity, and stability. The design of new technologies as well as the retrofitting of existing technologies must fulfil requirements of green chemistry principles, such as limitation of waste production, use of reactants with no or limited environmental impact, processes with decreased energy consumption, use of renewable feedstock, and the preferential role of catalytic reagents over stoichiometric reagents. Meeting these requirements can be supported by application of advanced catalytic systems based on nano-porous materials implemented with nano-sized transition metal species. Thus, the main goal of this Special Issue is to present progress in the synthesis of advanced catalysts for green chemistry processes based on nano-porous materials.

Submissions to this Special Issue, “Nano-Porous Materials in Green Chemistry Processes”, are welcome in the form of original research papers or short reviews reflecting upon the knowledge in the field of nano-porous materials and their applications in green chemistry processes. These include, but are not limited to, zeolites, mesoporous silicas, modified clay minerals, nano-sized transition metals oxide species, active carbons, carbon nanotubes and their applications in green chemistry processes, environmental catalysis, eco-friendly synthesis of fuels and chemicals, and biomass valorization.

Prof. Dr. Roman Dziembaj
Prof. Dr. Lucjan Chmielarz
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 submissions that pass pre-check are 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. Catalysts is an international peer-reviewed open access monthly 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 2200 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

  • Zeolites
  • Mesoporous silicas
  • Modified clay minerals
  • Nano-structured catalysts
  • Nano-sized transition metal oxide species
  • Functional carbon materials
  • Green chemistry processes
  • Environmental and sustainable catalysis
  • Eco-friendly synthesis of fuels and chemicals
  • Biomass valorization

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (11 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

12 pages, 5302 KiB  
Article
Three-Dimensional Hierarchical Hydrotalcite–Silica Sphere Composites as Catalysts for Baeyer–Villiger Oxidation Reactions Using Hydrogen Peroxide
by Daniel Cosano, Dolores Esquivel, Francisco J. Romero-Salguero, César Jiménez-Sanchidrián and José Rafael Ruiz
Catalysts 2022, 12(6), 629; https://doi.org/10.3390/catal12060629 - 8 Jun 2022
Cited by 2 | Viewed by 1942
Abstract
The development of effective, environmentally friendly catalysts for the Baeyer–Villiger reaction is becoming increasingly important in applied catalysis. In this work, we synthesized a 3D composite consisting of silica spheres coated with Mg/Al hydrotalcite with much better textural properties than its 2D counterparts. [...] Read more.
The development of effective, environmentally friendly catalysts for the Baeyer–Villiger reaction is becoming increasingly important in applied catalysis. In this work, we synthesized a 3D composite consisting of silica spheres coated with Mg/Al hydrotalcite with much better textural properties than its 2D counterparts. In fact, the 3D solid outperformed a 2D-layered hydrotalcite as catalyst in the Baeyer–Villiger reaction of cyclic ketones with H2O2/benzonitrile as oxidant. The 3D catalyst provided excellent conversion and selectivity; it was also readily filtered off the reaction mixture. The proposed reaction mechanism, which involves adsorption of the reactants on the hydrotalcite surface, is consistent with the catalytic activity results. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Figure 1

17 pages, 4938 KiB  
Article
Conversion of Weathered Coal into High Value-Added Humic Acid by Magnetically Recoverable Fe3O4/LaNiO3 Nanocatalysts under Solid-Phase Grinding Conditions
by Manrong Song, Gang Wang, Yanli Suo, Zhiqiang Wu, Haijuan Zhan and Wanyi Liu
Catalysts 2022, 12(4), 392; https://doi.org/10.3390/catal12040392 - 31 Mar 2022
Cited by 9 | Viewed by 2543
Abstract
The Fe3O4/LaNiO3 composite, synthesised with the sol-gel method, is considered to be an excellent nanocatalyst for the production of high value-added humic acids from oxidised weathered coal under solid phase milling process conditions. Under optimum process conditions (1% [...] Read more.
The Fe3O4/LaNiO3 composite, synthesised with the sol-gel method, is considered to be an excellent nanocatalyst for the production of high value-added humic acids from oxidised weathered coal under solid phase milling process conditions. Under optimum process conditions (1% catalyst, 10% activator, 60 min grinding), 48.4% of the weathered coal can be oxidised to produce humic acid. The prepared Fe3O4/LaNiO3 catalyst was characterized by HRTEM, XRD, and XPS, etc. The heterojunction structure that can promote the electron transfer between the components of the composite material was formed with the recombination of Fe3O4 and LaNiO3. The activation of surface oxygen species and adsorbed oxygen could be enhanced with the help of electron transfer between components. Compared to the blank sample or the LaNiO3 catalyst alone, the molecular weight of the humic acid produced using the Fe3O4/LaNiO3 composite catalyst was significantly lower (maximum heavy mean molecular weight decreased from 59.7 kDa to 5.5 kDa) and the number of reactive groups in humic acid increased (to seven times that of the blank sample). Oxygen-free vacuum experiments indicated that O2 has an indispensable effect on its excellent catalytic performance in the Fe3O4/LaNiO3 system. In addition, Fe3O4/LaNiO3 could be used at least six times by simple magnetic separation. The development and preparation of perovskite composite catalysts provide a promising approach to the environmentally friendly development and application of weathered coal, as well as an effective method to resolve the associated environmental pollution. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

21 pages, 3334 KiB  
Article
Effect of Reaction Time and Hydrothermal Treatment Time on the Textural Properties of SBA-15 Synthesized Using Sodium Silicate as a Silica Source and Its Efficiency for Reducing Tobacco Smoke Toxicity
by Nerea Juárez-Serrano, Desiré Berenguer, Isabel Martínez-Castellanos, Inmaculada Blasco, Maribel Beltrán and Antonio Marcilla
Catalysts 2021, 11(7), 808; https://doi.org/10.3390/catal11070808 - 30 Jun 2021
Cited by 3 | Viewed by 2091
Abstract
The synthesis of SBA-15 has been optimized using sodium silicate, an inexpensive precursor of SBA-15. In this work, the influence of synthesis times of the precipitation and the hydrothermal treatment steps, on the textural properties developed as well as for reducing the toxic [...] Read more.
The synthesis of SBA-15 has been optimized using sodium silicate, an inexpensive precursor of SBA-15. In this work, the influence of synthesis times of the precipitation and the hydrothermal treatment steps, on the textural properties developed as well as for reducing the toxic compounds generated in tobacco smoking, has been studied. The hydrothermal treatment has been proved to be necessary to obtain materials with adequate performance in this particular application. Twenty-four hours of hydrothermal treatment provide materials with the best properties. Although the reaction stage usually involves the mixing of reagents during 24 h, 40 min is enough to obtain a material with stick-like morphology and typical textural properties. Moreover, between 1 and 2 h of reaction time, the material proved to have the best performance for the purpose of reducing the toxicity of the products generated during the tobacco smoking process. These results are of great significance for an eventual scaling up to industrial scale of the SBA-15 manufacturing process. Results of a pilot plant experiment in a batch of 4 kg of SBA-15 are reported. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

19 pages, 6922 KiB  
Article
Continuous 2-Methyl-3-butyn-2-ol Selective Hydrogenation on Pd/γ-Al2O3 as a Green Pathway of Vitamin A Precursor Synthesis
by Antonio J. Fernández-Ropero, Bartosz Zawadzki, Emil Kowalewski, Izabela S. Pieta, Mirosław Krawczyk, Krzysztof Matus, Dmytro Lisovytskiy and Anna Śrębowata
Catalysts 2021, 11(4), 501; https://doi.org/10.3390/catal11040501 - 15 Apr 2021
Cited by 14 | Viewed by 3102
Abstract
In this work, the effect of pretreatment conditions (10% H2/Ar flow rate 25 mL/min and 400 °C, 3 h or 600 °C, 17 h) on the catalytic performance of 1 wt.% Pd/γ-Al2O3 has been evaluated for hydrogenation of [...] Read more.
In this work, the effect of pretreatment conditions (10% H2/Ar flow rate 25 mL/min and 400 °C, 3 h or 600 °C, 17 h) on the catalytic performance of 1 wt.% Pd/γ-Al2O3 has been evaluated for hydrogenation of 2-methyl-3-butyn-2-ol in continuous-flow mode. Two palladium catalysts have been tested under different conditions of pressure and temperature and characterized using various physicochemical techniques. The catalytic performance of red(400 °C)-Pd/γ-Al2O3 and red(600 °C)-Pd/γ-Al2O3 are affected by the coexistence of several related factors like the competition between PdH and PdCx formation during the reaction, structure sensitivity, hydrogen spillover to the alumina support and presence or absence of Pd–Al species. High-temperature reduction leads to formation of Pd–Al species in addition to pure Pd. The Pd–Al species which reveal unique electronic properties by decreasing the Pdδ− surface concentration via electron transfer from Pd to Al, leading to a weaker Pd–Alkyl bonding, additionally assisted by the hydrogen spillover, are the sites of improved semi-hydrogenation of 2-methyl-3-butyn-2-ol towards 2-methyl-3-buten-2-ol (97%)—an important intermediate for vitamin A synthesis. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

18 pages, 2149 KiB  
Article
Insight into Active Centers and Anti-Coke Behavior of Niobium-Containing SBA-15 for Glycerol Dehydration
by Katarzyna Stawicka, Maciej Trejda and Maria Ziolek
Catalysts 2021, 11(4), 488; https://doi.org/10.3390/catal11040488 - 11 Apr 2021
Cited by 4 | Viewed by 2431
Abstract
Niobium containing SBA-15 was prepared by two methods: impregnation with different amounts of ammonium niobate(V) oxalate (Nb-15/SBA-15 and Nb-25/SBA-15 containing 15 wt.% and 25 wt.% of Nb, respectively) and mixing of mesoporous silica with Nb2O5 followed by heating at 500 [...] Read more.
Niobium containing SBA-15 was prepared by two methods: impregnation with different amounts of ammonium niobate(V) oxalate (Nb-15/SBA-15 and Nb-25/SBA-15 containing 15 wt.% and 25 wt.% of Nb, respectively) and mixing of mesoporous silica with Nb2O5 followed by heating at 500 °C (Nb2O5/SBA-15). The use of these two procedures allowed obtaining materials with different textural/surface properties determined by N2 adsorption/desorption isotherms, XRD, UV-Vis, pyridine, and NO adsorption combined with FTIR spectroscopy. Nb2O5/SBA-15 contained exclusively crystalline Nb2O5 on the SBA-15 surface, whereas the materials prepared by impregnation had both metal oxide and niobium incorporated into the silica matrix. The niobium species localized in silica framework generated Brønsted (BAS) and Lewis (LAS) acid sites. The inclusion of niobium into SBA-15 skeleton was crucial for the achievement of high catalytic performance. The strongest BAS were on Nb-25/SBA-15, whereas the highest concentration of BAS and LAS was on Nb-15/SBA-15 surface. Nb2O5/SBA-15 material possessed only weak LAS and BAS. The presence of the strongest BAS (Nb-25/SBA-15) resulted in the highest dehydration activity, whereas a high concentration of BAS was unfavorable. Silylation of niobium catalysts prepared by impregnation reduced the number of acidic sites and significantly increased acrolein yield and selectivity (from ca. 43% selectivity for Nb-25/SBA-15 to ca. 61% for silylated sample). This was accompanied by a considerable decrease in coke formation (from 47% selectivity for Nb-25/SBA-15 to 27% for silylated material). Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

12 pages, 2151 KiB  
Article
Structure-Catalytic Properties Relationship in Friedel Crafts Alkylation Reaction for MCM-36-Type Zeolites Obtained by Isopropanol-Assisted Pillaring
by Karolina Ogorzały, Agnieszka Węgrzyn, Aleksandra Korzeniowska, Andrzej Sławek, Andrzej Kowalczyk, Barbara Gil, Wiesław J. Roth and Wacław Makowski
Catalysts 2021, 11(3), 299; https://doi.org/10.3390/catal11030299 - 25 Feb 2021
Cited by 3 | Viewed by 3079
Abstract
MWW type zeolites are characterized by the presence of zeolitic layers of 2.5 nm thickness, containing 10-member ring sinusoidal channels inside and supercavities with 12-member ring openings located on their surfaces. Expansion and pillaring of layered zeolites increase the access to active sites and [...] Read more.
MWW type zeolites are characterized by the presence of zeolitic layers of 2.5 nm thickness, containing 10-member ring sinusoidal channels inside and supercavities with 12-member ring openings located on their surfaces. Expansion and pillaring of layered zeolites increase the access to active sites and can enable or facilitate catalytic activity towards larger reactant molecules. This goal is explored in this work reporting the pillaring of layered zeolite MCM-56 with MWW topology by tetraethylorthosilicate (TEOS) treatment with the assistance of isopropanol, aimed at obtaining hierarchical micro-mesoporous systems. MCM-56 (Si/Al = 12) was synthesized with hexamethyleneimine as a structure-directing and aniline as a structure-promoting agent. Hierarchical porous systems were obtained using two different pillaring methods: (1) with TEOS only and (2) with TEOS mixed with isopropanol. The MWW framework was preserved during swelling/pillaring in both methods. Pillared zeolites obtained via alcohol-assisted pillaring possessed unique intermediate micro-mesopores with the size of about 2 nm. IR study revealed a decrease in the concentration of accessible acid centers upon pillaring. However, the fraction of acid sites on the external surface, accessible for adsorption of large molecules, increased by up to 90%. Catalytic activity was evaluated in the Friedel-Crafts alkylation of mesitylene with benzyl alcohol. Pillaring resulted in reduction of the acid site concentrations, but the materials retained high catalytic activity. Pillaring in the presence of alcohol produced increased turnover frequency values based on the concentrations of the external acid sites. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

Review

Jump to: Research

21 pages, 403 KiB  
Review
Synthesis and Specific Properties of the Ceria and Ceria-Zirconia Nanocrystals and Their Aggregates Showing Outstanding Catalytic Activity in Redox Reactions—A Review
by Roman Dziembaj, Marcin Molenda and Lucjan Chmielarz
Catalysts 2023, 13(8), 1165; https://doi.org/10.3390/catal13081165 - 29 Jul 2023
Cited by 5 | Viewed by 2159
Abstract
Non-stoichiometric CeO2−y, especially in the form of nanocrystal aggregates, exhibits exceptional catalytic activity in redox reactions. It significantly improves the activity of transition metals and their oxides dispersed on/or in it, also acting as an oxygen buffer. Particularly, active oxygen species [...] Read more.
Non-stoichiometric CeO2−y, especially in the form of nanocrystal aggregates, exhibits exceptional catalytic activity in redox reactions. It significantly improves the activity of transition metals and their oxides dispersed on/or in it, also acting as an oxygen buffer. Particularly, active oxygen species (O2n−, O−) are generated at the M/CeO2−y nanoparticle interface, as well as in the surface layer of their solid-state solutions MxCe1−xO2−y. The crystal structure of CeO2, ZrO2 and (Ce, Zr)O2 and its defects are discussed in connection with the resulting specific catalytic activity. All the methods (simple precipitation and co-precipitation from mother liquors, sol–gel methods, precipitation from nanoemulsions, hydrothermal and solvothermal techniques, combustion and flame spray pyrolysis, precipitation using molecular and solid-state matrices, 3D printing and mechanochemical methods) used for the synthesis of these nanomaterials are comprehensively reviewed, describing the rules of individual procedures and preparation details. Methods of deposition of metal catalysts and their oxides on CeO2 nanoparticles, such as impregnation, washcoating and precipitation deposition, were also discussed. This review contains more than 160 references to representative papers wherein the reader can find further details on individual syntheses of effective ceria-based catalysts for redox reactions. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
28 pages, 5405 KiB  
Review
Engineering Heterostructures of Layered Double Hydroxides and Metal Nanoparticles for Plasmon-Enhanced Catalysis
by Diana Gilea, Radu G. Ciocarlan, Elena M. Seftel, Pegie Cool and Gabriela Carja
Catalysts 2022, 12(10), 1210; https://doi.org/10.3390/catal12101210 - 11 Oct 2022
Cited by 2 | Viewed by 2573
Abstract
Artificially designed heterostructures formed by close conjunctions of plasmonic metal nanoparticles (PNPs) and non-plasmonic (2D) lamellar nanostructures are receiving extensive interest. The synergistic interactions of the nanounits induce the manifestation of localized surface plasmon resonance (LSPR) in plasmonic metals in the specific environment [...] Read more.
Artificially designed heterostructures formed by close conjunctions of plasmonic metal nanoparticles (PNPs) and non-plasmonic (2D) lamellar nanostructures are receiving extensive interest. The synergistic interactions of the nanounits induce the manifestation of localized surface plasmon resonance (LSPR) in plasmonic metals in the specific environment of the 2D-light absorbing matrix, impacting their potential in plasmon enhanced catalysis. Specifically, layered double hydroxides (LDH) with the advantages of their unique 2D-layered structure, tuned optical absorption, ease of preparation, composition diversity, and high surface area, have emerged as very promising candidates for obtaining versatile and robust catalysts. In this review, we cover the available PNPs/LDH heterostructures, from the most used noble-metals plasmonic of Au and Ag to the novel non-noble-metals plasmonic of Cu and Ni, mainly focusing on their synthesis strategies toward establishing a synergistic response in the coupled nanounits and relevant applications in plasmonic catalysis. First, the structure–properties relationship in LDH, establishing the desirable features of the 2D-layered matrix facilitating photocatalysis, is shortly described. Then, we address the recent research interests toward fabrication strategies for PNPs/support heterostructures as plasmonic catalysts. Next, we highlight the synthesis strategies for available PNPs/LDH heterostructures, how these are entangled with characteristics that enable the manifestation of the plasmon-induced charge separation effect (PICS), co-catalytic effect, or nanoantenna effect in plasmonic catalysis with applications in energy related and environmental photocatalysis. Finally, some perspectives on the challenges and future directions of PNPs/LDHs heterostructures to improve their performance as plasmonic catalysts are discussed. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Figure 1

74 pages, 7844 KiB  
Review
Titania-Clay Mineral Composites for Environmental Catalysis and Photocatalysis
by Ewa M. Serwicka
Catalysts 2021, 11(9), 1087; https://doi.org/10.3390/catal11091087 - 9 Sep 2021
Cited by 19 | Viewed by 4355
Abstract
The use of titania-based composite materials in the field of heterogeneous catalysis and photocatalysis has a long and rich history. Hybrid structures combining titania nanoparticles with clay minerals have been extensively investigated for nearly four decades. The attractiveness of clay minerals as components [...] Read more.
The use of titania-based composite materials in the field of heterogeneous catalysis and photocatalysis has a long and rich history. Hybrid structures combining titania nanoparticles with clay minerals have been extensively investigated for nearly four decades. The attractiveness of clay minerals as components of functional materials stems primarily from their compositional versatility and the possibility of using silicate lamellae as prefabricated building blocks ready to be fitted into the desired nanoconstruction. This review focuses on the evolution over the years of synthetic strategies employed for the manufacturing of titania–clay mineral composites with particular attention to the role of the adopted preparative approach in shaping the physical and chemical characteristics of the materials and enabling, ultimately, tuning of their catalytic and/or photocatalytic performance. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Figure 1

26 pages, 3231 KiB  
Review
Modified Layered Silicas as Catalysts for Conversion of Nitrogen Pollutants in Flue Gases—A Review
by Lucjan Chmielarz and Roman Dziembaj
Catalysts 2021, 11(5), 644; https://doi.org/10.3390/catal11050644 - 19 May 2021
Cited by 11 | Viewed by 3054
Abstract
This paper is focused on the recent achievements in the studies of modified layered zeolites and cationic layered clay minerals. These materials are very promising catalysts in green chemistry processes, such as selective catalytic reduction of NOx with ammonia (NH3-SCR) [...] Read more.
This paper is focused on the recent achievements in the studies of modified layered zeolites and cationic layered clay minerals. These materials are very promising catalysts in green chemistry processes, such as selective catalytic reduction of NOx with ammonia (NH3-SCR) and selective catalytic oxidation of ammonia to dinitrogen (NH3-SCO). Special attention is paid to the roles of the micro- and mesoporous structures of the catalytic materials, the type and location of deposited transition metals, as well as surface acidity in the design of effective catalysts for the NH3-SCR and NH3-SCO processes. The majority of the presented analysis is based on the authors’ research. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

39 pages, 11070 KiB  
Review
Porous Silica-Based Organic-Inorganic Hybrid Catalysts: A Review
by Andrea Erigoni and Urbano Diaz
Catalysts 2021, 11(1), 79; https://doi.org/10.3390/catal11010079 - 8 Jan 2021
Cited by 40 | Viewed by 6199
Abstract
Hybrid organic-inorganic catalysts have been extensively investigated by several research groups in the last decades, as they allow combining the structural robust-ness of inorganic solids with the versatility of organic chemistry. Within the field of hybrid catalysts, synthetic strategies based on silica are [...] Read more.
Hybrid organic-inorganic catalysts have been extensively investigated by several research groups in the last decades, as they allow combining the structural robust-ness of inorganic solids with the versatility of organic chemistry. Within the field of hybrid catalysts, synthetic strategies based on silica are among the most exploitable, due to the convenience of sol-gel chemistry, to the array of silyl-derivative precursors that can be synthesized and to the number of post-synthetic functionalization strategies available, amongst others. This review proposes to highlight these advantages, firstly describing the most common synthetic tools and the chemistry behind sol-gel syntheses of hybrid catalysts, then presenting exemplificative studies involving mono- and multi-functional silica-based hybrid catalysts featuring different types of active sites (acid, base, redox). Materials obtained through different approaches are described and their properties, as well as their catalytic performances, are compared. The general scope of this review is to gather useful information for those approaching the synthesis of organic-inorganic hybrid materials, while providing an overview on the state-of-the art in the synthesis of such materials and highlighting their capacities. Full article
(This article belongs to the Special Issue Nano-Porous Materials for Catalytic Systems in Green Chemistry Processes)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-11
Back to TopTop