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Application of Green Catalysts in Industrial and Environmental Processes

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

Deadline for manuscript submissions: closed (28 February 2023) | Viewed by 24862

Special Issue Editor

Special Issue Information

Dear Colleagues,

The use of nanoparticles in both environmental and industrial catalyzed processes has recently undergone to a remarkable growth, considering the increasing number of published papers on these topics. In this framework, the possibility to synthetize the nano-catalysts with green-based reagents and solvents allows the producers to follow and respect the fundamental pillars of the Green Economy. Nanoparticles can be utilized directly as suspended materials and, more often, are supported by other materials. Both industrial and environmental processes, such as catalyzed methanation (Ni, Fe, and Ru-based catalysts), Fischer–Tropsch processes (Fe(0)-based nano-catalysts), heterogeneous fenton, and dehalogenation processes, can be intensified by means of nano-catalysts employment, mainly because of their peculiar properties related to the quantum size effect. In view of sustainable industrial process development, the green production of the used catalysts represents a fundamental step of the whole process.

In this Special Issue, interested researchers are invited to submit original research papers, as well as review articles, on any of the topics related to the production and/or use of green-based catalysts, with a particular focus on nano-sized catalysts.

Dr. Giorgio Vilardi
Guest Editor

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.

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 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

  • Green processes;
  • Process intensification;
  • Industrial catalysis;
  • Environmental catalysis;
  • Metallic-based catalysts;
  • Nanoparticles and microparticles;
  • Heterogeneous fenton;
  • Catalyzed methanation.

Published Papers (11 papers)

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Research

Jump to: Review

19 pages, 4413 KiB  
Article
Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions
by Álvaro Díaz-Verde, Salvador Montilla-Verdú, Verónica Torregrosa-Rivero and María-José Illán-Gómez
Molecules 2023, 28(8), 3327; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28083327 - 09 Apr 2023
Cited by 4 | Viewed by 1294
Abstract
Mixed oxides with perovskite-type structure (ABO3) are promising catalysts for atmospheric pollution control due to their interesting and tunable physicochemical properties. In this work, two series of BaxMnO3 and BaxFeO3 (x = 1 and 0.7) [...] Read more.
Mixed oxides with perovskite-type structure (ABO3) are promising catalysts for atmospheric pollution control due to their interesting and tunable physicochemical properties. In this work, two series of BaxMnO3 and BaxFeO3 (x = 1 and 0.7) catalysts were synthesized using the sol–gel method adapted to aqueous medium. The samples were characterized by μ-XRF, XRD, FT-IR, XPS, H2-TPR, and O2-TPD. The catalytic activity for CO and GDI soot oxidation was determined by temperature-programmed reaction experiments (CO-TPR and soot-TPR, respectively). The results reveal that a decrease in the Ba content improved the catalytic performance of both catalysts, as B0.7M-E is more active than BM-E for CO oxidation, and B0.7F-E presents higher activity than BF for soot conversion in simulated GDI engine exhaust conditions. Manganese-based perovskites (BM-E and B0.7M-E) achieve better catalytic performance than iron-based perovskite (BF) for CO oxidation reaction due to the higher generation of actives sites. Full article
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16 pages, 1497 KiB  
Article
A Series of Green Oxovanadium(IV) Precatalysts with O, N and S Donor Ligands in a Sustainable Olefins Oligomerization Process
by Mariusz Urbaniak, Kacper Pobłocki, Paweł Kowalczyk, Karol Kramkowski, Joanna Drzeżdżon, Barbara Gawdzik, Patrycja Świtała, Maja Miler, Daria Heleniak, Przemysław Rybiński and Dagmara Jacewicz
Molecules 2022, 27(22), 8038; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27228038 - 19 Nov 2022
Cited by 6 | Viewed by 1434
Abstract
Designing catalyst systems based on transition metal ions and activators using the principles of green chemistry is a fundamental research goal of scientists due to the reduction of poisonous solvents, metal salts and organic ligands released into the environment. Urgent measures to reduce [...] Read more.
Designing catalyst systems based on transition metal ions and activators using the principles of green chemistry is a fundamental research goal of scientists due to the reduction of poisonous solvents, metal salts and organic ligands released into the environment. Urgent measures to reduce climate change are in line with the goals of sustainable development and the new restrictive laws ordained by the European Union. In this report, we attempted to use known oxovanadium(IV) green complex compounds with O, N and S donor ligands, i.e., [VO(TDA)phen] • 1.5 H2O (TDA = thiodiacetate), (phen = 1,10-phenanthroline), oxovanadium(IV) microclusters with 2-phenylpyridine (oxovanadium(IV) cage), [VOO(dipic)(2-phepyH)] • H2O (dipic = pyridine-2,6-dicarboxylate anion), (2-phepyH = 2-phenylpyridine), [VO(dipic)(dmbipy)] • 2H2O (dmbipy = 4,4′-dimethoxy-2,2′-dipyridyl) and [VO(ODA)(bipy)] • 2 H2O (ODA = oxydiacetate), (bipy = 2,2′-bipyridine), as precatalysts in oligomerization reactions of 3-buten-2-ol, 2-propen-1-ol, 2-chloro-2-propen-1-ol and 2,3-dibromo-2-propen-1-ol. The precatalysts, in most cases, turned out to be highly active because the catalytic activity exceeded 1000 g mmol−1·h−1. In addition, the oligomers were characterized by Fourier-transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization (MALDI-TOF-MS), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Full article
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16 pages, 5823 KiB  
Article
Glycerol-Based Retrievable Heterogeneous Catalysts for Single-Pot Esterification of Palm Fatty Acid Distillate to Biodiesel
by Balkis Hazmi, Mahnoush Beygisangchin, Umer Rashid, Wan Nur Aini Wan Mokhtar, Toshiki Tsubota, Ali Alsalme and Chawalit Ngamcharussrivichai
Molecules 2022, 27(20), 7142; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27207142 - 21 Oct 2022
Cited by 2 | Viewed by 1812
Abstract
The by-product of the previous transesterification, glycerol was utilised as an acid catalyst precursor for biodiesel production. The crude glycerol was treated through the sulfonation method with sulfuric acid and chlorosulfonic acid in a reflux batch reactor giving solid glycerol-SO3H and [...] Read more.
The by-product of the previous transesterification, glycerol was utilised as an acid catalyst precursor for biodiesel production. The crude glycerol was treated through the sulfonation method with sulfuric acid and chlorosulfonic acid in a reflux batch reactor giving solid glycerol-SO3H and glycerol-ClSO3H, respectively. The synthesised acidic glycerol catalysts were characterised by various analytical techniques such as thermalgravimetric analyser (TGA), infrared spectroscopy, surface properties adsorption-desorption by nitrogen gas, ammonia-temperature programmed desorption (NH3-TPD), X-ray diffraction spectroscopy (XRD), elemental composition analysis by energy dispersive spectrometer (EDX) and surface micrographic morphologies by field emission electron microscope (FESEM). Both glycerol-SO3H and glycerol-ClSO3H samples exhibited mesoporous structures with a low surface area of 8.85 mm2/g and 4.71 mm2/g, respectively, supported by the microscopic image of blockage pores. However, the acidity strength for both catalysts was recorded at 3.43 mmol/g and 3.96 mmol/g, which is sufficient for catalysing PFAD biodiesel at the highest yield. The catalytic esterification was optimised at 96.7% and 98.2% with 3 wt.% of catalyst loading, 18:1 of methanol-PFAD molar ratio, 120 °C, and 4 h of reaction. Catalyst reusability was sustained up to 3 reaction cycles due to catalyst deactivation, and the insight investigation of spent catalysts was also performed. Full article
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17 pages, 3406 KiB  
Article
Photo-Assisted Removal of Rhodamine B and Nile Blue Dyes from Water Using CuO–SiO2 Composite
by Muhammad Yaseen, Muhammad Humayun, Abbas Khan, Muhammad Idrees, Nasrullah Shah and Shaista Bibi
Molecules 2022, 27(16), 5343; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27165343 - 22 Aug 2022
Cited by 14 | Viewed by 2096
Abstract
Wastewater from the textile industries contaminates the natural water and affects the aquatic environment, soil fertility and biological ecosystem through discharge of different hazardous effluents. Therefore, it is essential to remove such dissolved toxic materials from water by applying more efficient techniques. We [...] Read more.
Wastewater from the textile industries contaminates the natural water and affects the aquatic environment, soil fertility and biological ecosystem through discharge of different hazardous effluents. Therefore, it is essential to remove such dissolved toxic materials from water by applying more efficient techniques. We performed a comparative study on the removal of rhodamine B (RhB) and Nile blue (NB) from water through a catalytic/photocatalytic approach while using a CuO–SiO2 based nanocomposite. The CuO–SiO2 nanocomposite was synthesized through a sol–gel process using copper nitrate dihydrate and tetraethylorthosilicate as CuO and SiO2 precursors, respectively, with ammonia solution as the precipitating agent. The synthesized nanocomposites were characterized, for their structure, morphology, crystallinity, stability, surface area, pore size and pore volume, by using a scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) techniques. The CuO–SiO2 nanocomposite was used for potential environmental applications in the terms of its catalytic and photocatalytic activities toward the degradation of rhodamine B (RhB) and Nile blue (NB) dyes, in the presence and absence of light, while monitoring the degradation process of dyes by UV-Visible spectroscopy. The catalytic efficiency of the same composite was studied and discussed in terms of changes in the chemical structures of dyes and other experimental conditions, such as the presence and absence of light. Moreover, the composite showed 85% and 90% efficiency towards the removal of rhodamine B and Nile blue dyes respectively. Thus, the CuO–SiO2 nanocomposite showed better efficiency toward removal of Nile blue as compared to rhodamine B dye while keeping other experimental variables constant. This can be attributed to the structure–property relationships and compatibility of a catalyst with the molecular structures of dyes. Full article
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23 pages, 7480 KiB  
Article
Mineral Montmorillonite Valorization by Developing Ni and Mo–Ni Catalysts for Third-Generation Green Diesel Production
by Sotiris Lycourghiotis, Eleana Kordouli, John Zafeiropoulos, Christos Kordulis and Kyriakos Bourikas
Molecules 2022, 27(3), 643; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27030643 - 19 Jan 2022
Cited by 7 | Viewed by 1550
Abstract
Four Ni catalysts and one Mo–Ni catalyst supported on montmorillonite were synthesized, characterized by various techniques and evaluated, under solvent-free conditions, for the production of green diesel from waste cooking oil. The optimum Ni content was found to be 20 wt.%. The addition [...] Read more.
Four Ni catalysts and one Mo–Ni catalyst supported on montmorillonite were synthesized, characterized by various techniques and evaluated, under solvent-free conditions, for the production of green diesel from waste cooking oil. The optimum Ni content was found to be 20 wt.%. The addition of 2 wt.% Mo to the catalyst resulted in a considerable increase in the amount of green diesel hydrocarbons. The Mo species, moreover, led to a decrease in the (C15 + C17)/(C16 + C18) ratio, which is beneficial from the viewpoint of carbon atom economy. The promoting action of Mo was mainly attributed to the synergy between the oxygen vacancies on the surface of the well-dispersed Mo(V) and Mo(VI) oxides and the neighboring Ni0 sites. The optimum reaction conditions, for achieving a proportion of liquid product in the green diesel hydrocarbons (C15–18) equal to 96 wt.%, were found to be 350 °C, 3 g of catalyst per 100 mL of waste cooking oil and 13 h reaction time. These conditions correspond to an LHSV of 2.5 h−1, a value that is considered quite reliable from the viewpoint of industrial applications. Thus, the cheap and abundant mineral montmorillonite is proved a promising support for developing efficient Ni–Mo catalysts for green diesel production. Full article
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16 pages, 1928 KiB  
Article
Tungsten and Molybdenum Heteropolyanions with Different Central Ions—Correlation between Theory and Experiment
by Piotr Niemiec, Renata Tokarz-Sobieraj and Małgorzata Witko
Molecules 2022, 27(1), 187; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27010187 - 29 Dec 2021
Cited by 2 | Viewed by 1802
Abstract
Density functional theory calculations were carried out to investigate the electronic structures of Keggin-typed [XMo12O40]n− and [XW12O40]n− anions with different heteroatoms (X = Zn2+, B3+, Al3+, Ga [...] Read more.
Density functional theory calculations were carried out to investigate the electronic structures of Keggin-typed [XMo12O40]n− and [XW12O40]n− anions with different heteroatoms (X = Zn2+, B3+, Al3+, Ga3+, Si4+, Ge4+, P5+, As5+, and S6+). The influence of solvent on redox properties of heteropolyanions was discussed. For [XW12O40]n− systems two linear correlation: first, between the experimental redox potential and energies of LUMO orbital; and second, between the experimental redox potential and total energy interaction (calculated between internal tetrahedron (XO4n−), and rest of Kegging anion skeleton, (W12O36)) were designated. Taking into account the similarity of XW12O40n− and XMo12O40n− systems (in geometry and electronic structure), the estimated redox potential of molybdenum heteropolyanions (with X being p block elements) in different solvent were proposed. Full article
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15 pages, 5620 KiB  
Article
Preparation of KI/Hydroxyapatite Catalyst from Phosphate Rocks and Its Application for Improvement of Biodiesel Production
by Widayat Widayat, Hadiyanto Hadiyanto, Permadi Wisnu Aji Wardani, Ummi Az Zuhra and Jedy Prameswari
Molecules 2020, 25(11), 2565; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25112565 - 31 May 2020
Cited by 10 | Viewed by 2256
Abstract
The main aim of this work was to investigate the suitability of a KI/KIO3 impregnated hydroxyapatite (HAP) catalyst derived from natural phosphate rocks for biodiesel production. This study evaluated the effect of impregnation concentrations (1–6% w/w) on the catalyst [...] Read more.
The main aim of this work was to investigate the suitability of a KI/KIO3 impregnated hydroxyapatite (HAP) catalyst derived from natural phosphate rocks for biodiesel production. This study evaluated the effect of impregnation concentrations (1–6% w/w) on the catalyst performance in biodiesel production. The biodiesel was produced from waste cooking oil (WCO) under simultaneous esterification-transesterification reactions at 60 °C for 6 h. The results showed that the biodiesel yield increased by increasing impregnation concentration and the maximum yield (91.787%) was achieved at an impregnation concentration of 5% w/w. The KI/HAP catalyst showed better performance (91.78% biodiesel yield, 59.1% FAME yield and surface area of 13.513 m2/g) as compared to the KIO3/HAP catalyst (90.07% biodiesel yield, 55.0% FAME yield and surface area of 10.651 m2/g). Full article
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15 pages, 4474 KiB  
Article
Preparation of Activated Carbon Supported Bead String Structure Nano Zero Valent Iron in a Polyethylene Glycol-Aqueous Solution and Its Efficient Treatment of Cr(VI) Wastewater
by Chunlei Jiao, Xiao Tan, Aijun Lin and Wenjie Yang
Molecules 2020, 25(1), 47; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25010047 - 21 Dec 2019
Cited by 20 | Viewed by 2975
Abstract
Nanometer zero-valent iron (nZVI) has been widely used in the treatment of heavy metals such as hexavalent chromium (Cr(VI)). A novel composite of bead string-structured nZVI on modified activated carbon (nZVI–MAC) is prepared here, using polyethylene glycol as the stable dispersant rather than [...] Read more.
Nanometer zero-valent iron (nZVI) has been widely used in the treatment of heavy metals such as hexavalent chromium (Cr(VI)). A novel composite of bead string-structured nZVI on modified activated carbon (nZVI–MAC) is prepared here, using polyethylene glycol as the stable dispersant rather than traditional ethanol during the loading process. The microstructure characterization shows that nZVI particles are loaded on MAC with a bead string structure in large quantity and stably due to the addition of hydroxyl functional groups on the surface by polyethylene glycol. Experiments on the treatment of Cr(VI) in wastewater show that the reaction process requires only 20 min to achieve equilibrium. The removal rate of Cr(VI) with a low concentration (80–100 mg/L) is over 99% and the maximum saturation removal capacity is up to 66 mg/g. The system converts Cr(VI) to trivalent chromium (Cr(III)) through an oxidation-reduction effect and forms an insoluble material with iron ions by coprecipitation, which is then adsorbed on the surface of the nZVI–MAC. The process conforms to the quasi-second order adsorption kinetics equation (mainly chemical adsorption process). Full article
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Review

Jump to: Research

22 pages, 7025 KiB  
Review
A Comprehensive Review on Zeolite Chemistry for Catalytic Conversion of Biomass/Waste into Green Fuels
by Umair Yaqub Qazi, Rahat Javaid, Amir Ikhlaq, Asif Hussain Khoja and Faisal Saleem
Molecules 2022, 27(23), 8578; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27238578 - 05 Dec 2022
Cited by 7 | Viewed by 2458
Abstract
Numerous attempts have been made to produce new materials and technology for renewable energy and environmental improvements in response to global sustainable solutions stemming from fast industrial expansion and population growth. Zeolites are a group of crystalline materials having molecularly ordered micropore arrangements. [...] Read more.
Numerous attempts have been made to produce new materials and technology for renewable energy and environmental improvements in response to global sustainable solutions stemming from fast industrial expansion and population growth. Zeolites are a group of crystalline materials having molecularly ordered micropore arrangements. Over the past few years, progress in zeolites has been observed in transforming biomass and waste into fuels. To ensure effective transition of fossil energy carriers into chemicals and fuels, zeolite catalysts play a key role; however, their function in biomass usage is more obscure. Herein, the effectiveness of zeolites has been discussed in the context of biomass transformation into valuable products. Established zeolites emphasise conversion of lignocellulosic materials into green fuels. Lewis acidic zeolites employ transition of carbohydrates into significant chemical production. Zeolites utilise several procedures, such as catalytic pyrolysis, hydrothermal liquefaction, and hydro-pyrolysis, to convert biomass and lignocelluloses. Zeolites exhibit distinctive features and encounter significant obstacles, such as mesoporosity, pore interconnectivity, and stability of zeolites in the liquid phase. In order to complete these transformations successfully, it is necessary to have a thorough understanding of the chemistry of zeolites. Hence, further examination of the technical difficulties associated with catalytic transformation in zeolites will be required. This review article highlights the reaction pathways for biomass conversion using zeolites, their challenges, and their potential utilisation. Future recommendations for zeolite-based biomass conversion are also presented. Full article
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24 pages, 3763 KiB  
Review
Recent Advancements and Challenges in Lignin Valorization: Green Routes towards Sustainable Bioproducts
by Mati Ullah, Pengyang Liu, Shangxian Xie and Su Sun
Molecules 2022, 27(18), 6055; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27186055 - 16 Sep 2022
Cited by 6 | Viewed by 3269
Abstract
The aromatic hetero-polymer lignin is industrially processed in the paper/pulp and lignocellulose biorefinery, acting as a major energy source. It has been proven to be a natural resource for useful bioproducts; however, its depolymerization and conversion into high-value-added chemicals is the major challenge [...] Read more.
The aromatic hetero-polymer lignin is industrially processed in the paper/pulp and lignocellulose biorefinery, acting as a major energy source. It has been proven to be a natural resource for useful bioproducts; however, its depolymerization and conversion into high-value-added chemicals is the major challenge due to the complicated structure and heterogeneity. Conversely, the various pre-treatments techniques and valorization strategies offers a potential solution for developing a biomass-based biorefinery. Thus, the current review focus on the new isolation techniques for lignin, various pre-treatment approaches and biocatalytic methods for the synthesis of sustainable value-added products. Meanwhile, the challenges and prospective for the green synthesis of various biomolecules via utilizing the complicated hetero-polymer lignin are also discussed. Full article
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18 pages, 2437 KiB  
Review
New Strategies on Green Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol over Oxide Composites
by Yifei Zhang, Muhammad Shoaib Khalid, Meng Wang and Gao Li
Molecules 2022, 27(17), 5417; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27175417 - 24 Aug 2022
Cited by 2 | Viewed by 2305
Abstract
Dimethyl carbonate is a generally used chemical substance which is environmentally sustainable in nature and used in a range of industrial applications as intermediate. Although various methods, including methanol phosgenation, transesterification and oxidative carbonylation of methanol, have been developed for large-scale industrial production [...] Read more.
Dimethyl carbonate is a generally used chemical substance which is environmentally sustainable in nature and used in a range of industrial applications as intermediate. Although various methods, including methanol phosgenation, transesterification and oxidative carbonylation of methanol, have been developed for large-scale industrial production of DMC, they are expensive, unsafe and use noxious raw materials. Green production of DMC from CO2 and methanol is the most appropriate and eco-friendly method. Numerous catalysts were studied and tested in this regard. The issues of low yield and difficulty in tests have not been resolved fundamentally, which is caused by the inherent problems of the synthetic pathway and limitations imposed by thermodynamics. Electron-assisted activation of CO2 and membrane reactors which can separate products in real-time giving a maximum yield of DMC are also being used in the quest to find more effective production method. In this review paper, we deeply addressed green production methods of DMC using Zr/Ce/Cu-based nanocomposites as catalysts. Moreover, the relationship between the structure and activity of catalysts, catalytic mechanisms, molecular activation and active sites identification of catalysts are also discussed. Full article
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