Journal Description
Catalysts
Catalysts
is a peer-reviewed open access journal of catalysts and catalyzed reactions published monthly online by MDPI. The Romanian Catalysis Society (RCS) are partners of Catalysts journal and its members receive a discount on the article processing charge.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), Inspec, CAPlus / SciFinder, CAB Abstracts, and other databases.
- Journal Rank: JCR - Q2 (Chemistry, Physical) / CiteScore - Q1 (General Environmental Science )
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 12.9 days after submission; acceptance to publication is undertaken in 2.8 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
3.8 (2023);
5-Year Impact Factor:
3.9 (2023)
Latest Articles
Improved Microwave-Assisted Ethyl Levulinate Production Using Rice Husk-Derived Biobased Mesoporous Silica as Catalyst
Catalysts 2024, 14(8), 482; https://doi.org/10.3390/catal14080482 (registering DOI) - 27 Jul 2024
Abstract
This study presents the synthesis and characterization of mesoporous silica using biobased silica recovered from rice husks (RHs) as an excellent example of the circular economy. Distinct hydrothermal methods were used, namely, the autoclave hydrothermal method and microwave irradiation. Furthermore, the microwave-synthesized SBA-15
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This study presents the synthesis and characterization of mesoporous silica using biobased silica recovered from rice husks (RHs) as an excellent example of the circular economy. Distinct hydrothermal methods were used, namely, the autoclave hydrothermal method and microwave irradiation. Furthermore, the microwave-synthesized SBA-15 material was subjected to post-functionalization with –SO3H groups using the organosilane 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane (CSPTMS). The structural and chemical properties of the prepared materials were rigorously characterized through several techniques, thereby confirming the successful preparation of this functionalized material. Subsequently, the functionalized SBA-15 (CSPTMS@SBA-15) was employed as a catalyst in the synthesis of ethyl levulinate (EL) from 5-hydroxymethylfurfural (5-HMF) using different methodologies: typical high-pressure batch reactor, conventional heating, and microwave irradiation. This investigation aimed to elucidate the influence of microwave and non-microwave heating methods on the efficient conversion of 5-HMF into EL. The findings revealed that the microwave reactor exhibited superior conversion rates and selectivity when compared to the non-microwave heating methods. The study also explored the effects of temperature and utilization of various alcohols as both solvents and reagents. The results demonstrated that higher temperatures favored the production of alkyl levulinate and that complete conversion of 5-HMF was attainable for all the alcohols employed. Specifically, for methanol and ethanol a 100% yield of alkyl levulinates was achieved, while for 1-propanol and butanol a reduction in the yield of alkyl levulinates was observed. These outcomes underscore the feasibility of achieving significant yields of various alkyl levulinates through the utilization of CSPTMS@SBA-15 as a catalyst.
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(This article belongs to the Special Issue Cutting-Edge Catalytic Biomass Conversion in Europe)
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Catalytic Cascade for Biomass Valorisation: Coupled Hydrogen Transfer Initiated Dehydration and Self-Aldol Condensation for the Synthesis of 2-methyl-pent-2-enal from 1,3-propanediol
by
Yueyuan Ma, Yue-Ming Wang, Fabio Lorenzini and Andrew Craig Marr
Catalysts 2024, 14(8), 481; https://doi.org/10.3390/catal14080481 (registering DOI) - 27 Jul 2024
Abstract
A one-pot, one-step protocol combining hydrogen transfer initiated dehydration (HTID) of 1,3-propanediol (1,3-PDO), catalysed by [Cp*IrCl2(NHC)] (Cp* = pentamethylcyclopentadienyl; NHC = carbene ligand) complexes (1-5H and 1-3F), and self-aldol condensation (SAC) of propanal (2), allowed selective production
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A one-pot, one-step protocol combining hydrogen transfer initiated dehydration (HTID) of 1,3-propanediol (1,3-PDO), catalysed by [Cp*IrCl2(NHC)] (Cp* = pentamethylcyclopentadienyl; NHC = carbene ligand) complexes (1-5H and 1-3F), and self-aldol condensation (SAC) of propanal (2), allowed selective production of C6 aldehyde 2-methyl-pent-2-enal (3), in ionic liquids with high substrate conversion. This shows, for the first time, the conversion of 1,3-propanediol to C6 aldehydes in one pot via a catalytic hydrogen borrowing methodology. The Ir(III) pre-catalysts and the ionic liquids were recyclable. C6 aldehyde 2-methyl-pent-2-enal could also be selectively produced in the presence of water and in neat 1,3-PDO. The efficient, selective delivery of a value-added chemical from 1,3-PDO, a major product of many whole-cell bacterial fermentation processes, shows that the combination of chemo-catalytic processing of the chemical platform via Cp*IrCl2(NHC)-catalysed HTID/SAC with bio-catalysis has the potential to allow direct valorisation of the bio-renewable feedstocks, such as waste glycerol and sugars, into valuable chemicals.
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(This article belongs to the Special Issue Catalysis for Reducing Carbon Footprint and Environmental Impacts)
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The Influence of the ZrO2 Crystal Phase on Cu/ZrO2-Al2O3 Catalysts in Methanol Steam Reforming
by
Mouxiao Song, Li Li, Xueshuang Wu, Haiqing Cai, Guiying Li and Changwei Hu
Catalysts 2024, 14(8), 480; https://doi.org/10.3390/catal14080480 (registering DOI) - 27 Jul 2024
Abstract
Copper-based catalysts are widely used in methanol steam reforming to produce hydrogen. In this paper, the supportive effect of the crystal phase of ZrO2 on Cu-based catalysts in methanol steam reforming is discussed. Monoclinic(m-), Tetragonal(t-) and mixed ZrO
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Copper-based catalysts are widely used in methanol steam reforming to produce hydrogen. In this paper, the supportive effect of the crystal phase of ZrO2 on Cu-based catalysts in methanol steam reforming is discussed. Monoclinic(m-), Tetragonal(t-) and mixed ZrO2 phases were prepared, and structure–activity relationships were investigated with XRD, H2-TPR, BET, HR-TEM and XPS. It was found that the catalyst with a 81.4% monoclinic ZrO2 crystal phase exhibited the highest methanol conversion (88.5%) and the highest hydrogen production rate (104.6 μmol/gcat·s) at 275 °C as it displayed the best reducing properties and more oxygen vacancies on the catalyst surface. Oxygen vacancies can produce more Cu1+ + Cu0, which is the active species for methanol steam reforming on the catalyst surface, and therefore affect catalytic activity.
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(This article belongs to the Section Catalysis for Sustainable Energy)
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Open AccessArticle
Efficient Methylene Blue Degradation by Activation of Peroxymonosulfate over Co(II) and/or Fe(II) Impregnated Montmorillonites
by
Niurka Barrios-Bermúdez, Arisbel Cerpa-Naranjo and María Luisa Rojas-Cervantes
Catalysts 2024, 14(8), 479; https://doi.org/10.3390/catal14080479 (registering DOI) - 27 Jul 2024
Abstract
Two commercial montmorillonites, namely montmorillonite K10 (MK10) and montmorillonite pillared with aluminum (MPil) were impregnated with cobalt(II) and/or iron(II) acetates by incipient wetness impregnation and used to activate peroxymonosulfate (PMS) for the degradation of methylene blue (MB) dye in water. Various characterization techniques,
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Two commercial montmorillonites, namely montmorillonite K10 (MK10) and montmorillonite pillared with aluminum (MPil) were impregnated with cobalt(II) and/or iron(II) acetates by incipient wetness impregnation and used to activate peroxymonosulfate (PMS) for the degradation of methylene blue (MB) dye in water. Various characterization techniques, including ICP-MS, XRD, SEM and TEM with EDX, and N2 physisorption, confirmed the successful impregnation process. The removal of the dye resulted from a combined effect of adsorption and PMS activation through Co3+/Co2+ redox couples. The MK10 series exhibited a higher degree of dye adsorption compared to the MPil series, leading to enhanced dye decomposition and superior catalytic performance in the former. The influence of catalyst mass, dye concentration, and initial pH was investigated. SO4•− radicals were found as the dominant reactive oxygen species. Co2+-impregnated montmorillonites showed better performance than their Fe2+-impregnated counterparts, with MK10-Co achieving complete MB removal in just 20 min. High degradation values of MB were achieved using lower PMS/MB ratios and amount of catalyst than others reported in the literature, showing the efficiency of cobalt-impregnated montmorillonites. Moreover, the catalysts maintained excellent catalytic activity after three reaction cycles.
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(This article belongs to the Section Catalytic Materials)
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Open AccessArticle
Electrochemical Detection of Dopamine: Novel Thin-Film Ti-Nanocolumnar Arrays/Graphene Monolayer-Cufoil Electrodes
by
Georgia Balkourani, José Miguel García-Martín, Elena Gorbova, Carmelo Lo Vecchio, Vincenzo Baglio, Angeliki Brouzgou and Panagiotis Tsiakaras
Catalysts 2024, 14(8), 478; https://doi.org/10.3390/catal14080478 (registering DOI) - 27 Jul 2024
Abstract
Deposition at oblique vapor incidence angles can lead to the growth of thin films with dramatically changed morphological features. Herein, thin-film titanium nanocolumnar arrays were grown on a graphene monolayer/copper foil substrate (TiNCs/Gm-Cufoil) by applying a physical
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Deposition at oblique vapor incidence angles can lead to the growth of thin films with dramatically changed morphological features. Herein, thin-film titanium nanocolumnar arrays were grown on a graphene monolayer/copper foil substrate (TiNCs/Gm-Cufoil) by applying a physical vapor deposition method, through magnetron sputtering at an oblique angle. Ti-nanocolumnar arrays with ca. 200 nm length were developed throughout the substrate with different morphologies depending on the substrate topography. It was found that over the as-fabricated electrocatalyst, the electrooxidation reaction of dopamine is facilitated, allowing quasi-reversible electrooxidation of protonated dopamine to dopamine quinone. Additionally, contrary to works that appeared in the literature, TiNCs/Gm-Cufoil also promotes further quasi-reversible oxidation of leucodopaminechrome to dopaminechrome. The electrode exhibited two linear ranges of dopamine detection (10–90 μM with a sensitivity value of 0.14 μAμM−1cm−2 and 100–400 μM with a sensitivity value of 0.095 μAμM−1cm−2), a good stability over time of about 30 days, and a good selectivity for dopamine detection.
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(This article belongs to the Section Electrocatalysis)
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Open AccessArticle
Facile Immersing Synthesis of Pt Single Atoms Supported on Sulfide for Bifunctional toward Seawater Electrolysis
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Jian Shen, Guotao Yang, Tianshui Li, Wei Liu, Qihao Sha, Zheng Zhong and Yun Kuang
Catalysts 2024, 14(8), 477; https://doi.org/10.3390/catal14080477 - 26 Jul 2024
Abstract
Seawater electrolysis for hydrogen production represents a substantial opportunity to curtail production expenditures and exhibits considerable potential for various industrial applications. Platinum-based precious metals exhibit excellent activity for water electrolysis. However, their limited reserves and high costs impede their widespread use on a
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Seawater electrolysis for hydrogen production represents a substantial opportunity to curtail production expenditures and exhibits considerable potential for various industrial applications. Platinum-based precious metals exhibit excellent activity for water electrolysis. However, their limited reserves and high costs impede their widespread use on a large scale. Single-atom catalysts, characterized by low loading and high utilization efficiency, represent a viable alternative, and the development of simple synthesis methods can facilitate their practical application. In this work, we report the facile synthesis of a single-atom Pt-loaded NiCoFeSx (Pt@NiCoFeSx) bifunctional catalytic electrode using a simple impregnation method on a nickel foam substrate. The resulting electrode exhibits low overpotentials for both HER (60 mV@10 mA cm−2) and OER (201 mV@10 mA cm−2) in alkaline seawater electrolytes. When incorporated into a seawater electrolyzer, this electrode achieves a direct current energy consumption of only 4.18 kWh/Nm3H2 over a 100 h test period with negligible decay. These findings demonstrate the potential of our approach for industrial-scale seawater electrolysis.
Full article
(This article belongs to the Special Issue Electrocatalytic Water Oxidation, 2nd Edition)
Open AccessArticle
Construction of Cu2O-ZnO/Cellulose Composites for Enhancing the Photocatalytic Performance
by
Yuchen Li, Ming Yan, Xin Li and Jinxia Ma
Catalysts 2024, 14(8), 476; https://doi.org/10.3390/catal14080476 - 25 Jul 2024
Abstract
Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles
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Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles only have catalytic activity and electron–hole pairing under ultraviolet light. Therefore, Copper(I) oxide (Cu2O)-ZnO/cellulose composites with excellent photocatalytic performance were fabricated by loading Cu2O crystals and using cellulose fiber substrate in this work. Cu2O can increase the light absorption range (including ultraviolet light and visible light) of ZnO/cellulose composites. Moreover, Cellulose fibers can improve the contact area to pollution and photostability of the Cu2O/ZnO nanoparticles, thereby enhancing the photocatalytic activity. The Cu2O-ZnO/cellulose composite showed the highest photocatalytic activity for Methyl orange (MO) degradation, which was approximately 40% and 10% times higher than those of the ZnO/cellulose and Cu2O/ZnO composites, respectively. Moreover, the degradation rate of phenol reached 100% within 80 min. The highly enhanced activity of the Cu2O-ZnO/cellulose composite is attributed to the enlargement of the light absorption range and the formation of heterojunctions between the counterparts, which effectively suppress the recombination of the photogenerated charge carriers. Overall, this work aims to improve the photocatalytic activities of ZnO/cellulose composites by loading Cu2O crystals, hoping to provide a novel and efficient photocatalyst for wastewater treatment.
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(This article belongs to the Section Photocatalysis)
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Open AccessCommunication
The Hydrodeoxygenation of Phenol over Ni-P/Hβ and Ni-P/Ce-β: Modifying the Effects in Dispersity and Acidity
by
Lin Ma, Yan Li, Zhiquan Yu, Jie Zou, Yingying Jing and Wei Wang
Catalysts 2024, 14(8), 475; https://doi.org/10.3390/catal14080475 - 25 Jul 2024
Abstract
The supported Ni-P catalysts (marked as s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3)) were prepared by an incipient wetness step-impregnation method, and characterized by XRD, N2 physisorption, TEM, XPS, and NH3-TPD. The catalytic hydrodeoxygenation (HDO) performance was assessed using phenol in water (5.0 wt%)
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The supported Ni-P catalysts (marked as s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3)) were prepared by an incipient wetness step-impregnation method, and characterized by XRD, N2 physisorption, TEM, XPS, and NH3-TPD. The catalytic hydrodeoxygenation (HDO) performance was assessed using phenol in water (5.0 wt%) or in decalin (1.0 wt%) as the feed. After the introduction of Ce, the conversion of phenol increased due to the high dispersity of the active site. However, compared to s-Ni-P/Hβ(3), the amount of total and strong acid sites of s-Ni-P/Ce-β(3) decreased, restraining the cycloisomerization of cyclohexane to form methyl-cyclopentane. Moreover, the kinetics of the APHDO and OPHDO of phenol catalyzed by s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3) were investigated.
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(This article belongs to the Special Issue Advances in Catalysis for Sustainable Energy and Environmental Remediation)
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Open AccessFeature PaperArticle
BiVO4-Based Photocatalysts for the Degradation of Antibiotics in Wastewater: Calcination Role after Solvothermal Synthesis
by
Jhon Mauricio Aguirre-Cortes, Adriana Isabel Moral-Rodríguez, Esther Bailón-García, Francisco Carrasco-Marín and Agustín Francisco Pérez-Cadenas
Catalysts 2024, 14(8), 474; https://doi.org/10.3390/catal14080474 - 25 Jul 2024
Abstract
BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via
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BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior.
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(This article belongs to the Special Issue Featured Papers in “Environmental Catalysis” Section)
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Open AccessFeature PaperArticle
Immobilization of Laccase in β-Cyclodextrin Composite Hydrogel for Efficient Degradation of Dye Pollutants
by
Hong Zhang, Zhi Wang, Fengxi Li, Lei Wang and Bo Ren
Catalysts 2024, 14(8), 473; https://doi.org/10.3390/catal14080473 - 24 Jul 2024
Abstract
A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of
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A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of mesopores and macropores existed in the wall of the hydrogel lamellae. This network structure reduced the diffusion resistance of the hydrogel to the target substrate. The relative activity of the resulting Lac-CD-PAA could be maintained at 35.8% after six cycles of use. Lac-CD-PAA exhibited higher thermal and chemical stability compared to free laccase. The negative charge on the surface of Lac-CD-PAA gives it the ability to pretreat cationic dyes. In six consecutive methylene blue decolorization tests, Lac-CD-PAA decolorized better than free laccase. The results showed that the prepared β-cyclodextrin-based composite hydrogel was a good carrier for laccase.
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(This article belongs to the Special Issue Enzyme Catalysis and Enzyme Engineering)
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Green Synthesis of Copper Oxide Nanoparticles from Waste Solar Panels Using Piper nigrum Fruit Extract and Their Antibacterial Activity
by
Ayesha Shafiq, Ujin Jeong, Yunseon Han, Youngsik Kim, Joonmin Lee and Beom Soo Kim
Catalysts 2024, 14(8), 472; https://doi.org/10.3390/catal14080472 - 24 Jul 2024
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To promote environmental development and sustain resource circularity, recycling metals from electronic waste is essential. Electronic waste is a significant secondary source of metals, with its production increasing rapidly and most remaining unrecycled. In solar panels, copper is the second-most-valuable metal after silver.
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To promote environmental development and sustain resource circularity, recycling metals from electronic waste is essential. Electronic waste is a significant secondary source of metals, with its production increasing rapidly and most remaining unrecycled. In solar panels, copper is the second-most-valuable metal after silver. We propose an innovative method to recycle copper from waste solar panels and convert it into copper oxide nanoparticles (CuONPs) using a green synthesis method. Synthesizing CuONPs is advantageous due to their large surface area compared to bulk material. Nitric acid, a strong oxidizing agent, was used to leach copper from solid copper wires in waste solar panels. A green synthesis method, following a bottom-up approach, was employed using Piper nigrum fruit extract to synthesize CuONPs. The synthesized nanoparticles were characterized using various qualitative and quantitative techniques. Spectroscopic analysis confirmed the formation of CuONPs, and transmission electron microscopy revealed that the nanoparticles were spherical with sizes up to 60 nm. Biomolecules from the Piper nigrum extract were detected on the surface of the crystalline CuONPs. These nanoparticles exhibited antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using a well-diffusion method, showing a larger zone of inhibition for E. coli compared to S. aureus. This research demonstrates the complete recovery of copper from waste solar panels and its conversion into useful CuONPs, which have potential medicinal applications.
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Open AccessArticle
Facile Synthesis of Sodium Alginate (SA)-Based Quaternary Bio-Nanocomposite (SA@Co-Zn-Ce) for Antioxidant Activity and Photocatalytic Degradation of Reactive Red 24
by
Sidra Fatima, Sana Javaid, Hira Ahmad, Afaf Almasoudi, Doaa F. Baamer, Omar Makram Ali, Sónia A. C. Carabineiro and Muhammad Babar Taj
Catalysts 2024, 14(8), 471; https://doi.org/10.3390/catal14080471 - 24 Jul 2024
Abstract
This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means
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This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means sodium alginate). This composite also demonstrated an exceptional antioxidant potential of approximately 89%, attributed to the synergistic effect of sodium alginate and green-synthesized Co–Zn–Ce nanoparticles (biosynthesized using Ocimum sanctum leaf extract as a reducing agent). Scanning electron microscopy revealed grain sizes of 28.6 nm for Co–Zn–Ce NPs and 25.59 nm for SA@Co–Zn–Ce nanocomposites (NCs). X-ray diffraction showed particle sizes of 16.87 nm and 15.43 nm, respectively. Co–Zn–Ce NPs exhibited a zeta potential of 1.99 mV, whereas the sodium alginate-anchored Co–Zn–Ce showed −7.99 mV. This indicated the entrapment of negatively charged ions from sodium alginate, altering the surface charge characteristics and enhancing the photocatalytic degradation of RR24. Dynamic light scattering revealed an average particle size of approximately 81 nm for SA@Co–Zn–Ce NCs, with the larger size due to the influence of water molecules in the colloidal solution affecting hydrodynamic diameter measurement. The SA@Co–Zn–Ce NCs exhibited a CO2 adsorption capacity of 3.29 mmol/g at 25 °C and 4.76 mmol/g at 40 °C, indicating temperature-dependent variations in adsorption capabilities. The specific surface area of Co–Zn–Ce oxide NPs, measured using Brunauer–Emmett–Teller (BET) analysis, was found to be 167.346 m2/g, whereas the SA@Co–Zn–Ce oxide nanocomposite showed a surface area of 24.14 m2/g. BJH analysis revealed average pore diameters of 34.60 Å for Co–Zn–Ce oxide NPs and 9.26 Å for SA@Co–Zn–Ce oxide NCs. Although the immobilization of sodium alginate on Co–Zn–Ce oxide NPs did not increase the adsorption sites and porosity of the composite, as evidenced by the N2 adsorption–desorption isotherms, the SA@Co–Zn–Ce oxide NCs still demonstrated a high photocatalytic degradation efficiency of RR24.
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(This article belongs to the Collection Nanocatalysis towards Energy Transition and Environmental Sustainability)
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Study on Catalytic Performance in CO2 Hydrogenation to Methanol over Au–Cu/C3N4 Catalysts
by
Chenyang Li, Jian Yang, Chongbin Zhang, Cong Wang, Chen Lyu and Kai Fan
Catalysts 2024, 14(8), 470; https://doi.org/10.3390/catal14080470 - 23 Jul 2024
Abstract
In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4
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In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4, catalysts were prepared and used for the catalytic reduction of CO2 to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO2, which is more beneficial for catalyzing CO2. Among them, Au-10%Cu/C3N4 exhibited good reducibility and strong basic sites, as demonstrated by H2-TPR and CO2-TPD, with the conversion rates for CO2, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg−1·h−1 (0.39 μmol·g−1s−1), and 59.77%, respectively.
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(This article belongs to the Special Issue Carbon-Based Catalysts for Water and Wastewater Treatment, 2nd Edition)
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Open AccessArticle
Photocatalytic Degradation of Paracetamol and Antibacterial Activity of La-Modified TiO2 Obtained by Non-Hydrolytic Sol–Gel Route
by
Angelina Stoyanova, Hristina Hitkova, Nina Kaneva, Albena Bachvarova-Nedelcheva, Reni Iordanova and Polya Marinovska
Catalysts 2024, 14(8), 469; https://doi.org/10.3390/catal14080469 - 23 Jul 2024
Abstract
The current study aims to synthesize and analyze both pure and La-doped TiO2, and evaluate the photocatalytic and antibacterial activity of as-prepared samples. Doped and undoped samples were prepared by the non-hydrolytic sol–gel method from titanium(IV) chloride, benzyl alcohol, and lanthanum(III)
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The current study aims to synthesize and analyze both pure and La-doped TiO2, and evaluate the photocatalytic and antibacterial activity of as-prepared samples. Doped and undoped samples were prepared by the non-hydrolytic sol–gel method from titanium(IV) chloride, benzyl alcohol, and lanthanum(III) nitrate followed by thermal treatment. Lanthanum content in synthesized samples was 0.4, 1, and 5 mol%. The resulting nanopowders’ structure and morphology were described using XRD, IR, and UV–Vis analysis. The average particle sizes of pure and doped TiO2 were about 6–15 nm and anatase was found to be a dominant crystalline phase in the samples. It was observed that particle sizes decreased on increasing La content. The photocatalytic activity of the pure and La-doped sol–gel powders was estimated in the decomposition of paracetamol in distilled water using ultraviolet light illumination. Doping with lanthanum ions has been shown to increase the photocatalytic properties on the degradation of paracetamol. Furthermore, the annealed catalysts (pure and La3+ doped) showed increased photocatalytic activity and degradation of the analgesic in comparison with non-annealed materials. In both cases, the highest photocatalytic efficiency is observed at the optimal La3+ (1 mol%) concentration. The antimicrobial activity of 1 mol% La/TiO2 was tested against a reference strain E. coli in the presence of ultraviolet light and in dark conditions. The number of viable bacterial cells was determined by a spread plate method, and kill curves were performed. The results showed that photoactivated 1 mol% La/TiO2 exhibited a strong bactericidal effect, and in concentration, 1 mg/mL efficiently killed bacteria at an initial cell density of about 105 colony forming units in 1 mL within 15 min.
Full article
(This article belongs to the Special Issue Nanostructures for Catalysis: From Synthesis and Characterization to Applications)
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Open AccessCommunication
A First-Principles Study on the Reaction Mechanisms of Electrochemical CO2 Reduction to C1 and C2 Products on Cu(110)
by
Yangyang Xu and Lixin Zhang
Catalysts 2024, 14(7), 468; https://doi.org/10.3390/catal14070468 - 22 Jul 2024
Abstract
The mechanism of the electrochemical CO2 reduction reaction on a Cu(110) surface has yet to be fully revealed. In this work, based on first-principles calculations, we investigate the mechanisms of the CO2 reduction reaction to produce C1 (including one C
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The mechanism of the electrochemical CO2 reduction reaction on a Cu(110) surface has yet to be fully revealed. In this work, based on first-principles calculations, we investigate the mechanisms of the CO2 reduction reaction to produce C1 (including one C atom) and C2 (including two C atoms) products on a Cu(110) surface. The results show that CH4 and C2H5OH are the main C1 and C2 products on the Cu(110) surface, respectively. CH4 is produced along the pathway CO2 → COOH* → CO* → CHO* → CH2O* → CH3O* → CH4. C2H5OH is produced via the C-C coupling pathway between CO* and CH2O* intermediates, which is the key reaction step. This is because CO* and CH2O* coupling to CO-CH2O* has the lowest barrier among the CHxO* (x = 0–2) coupling pathways. Therefore, it is the most likely C-C coupling pathway. Further, CO-CH2O* is gradually hydrogenated to C2H5OH along the following pathway: CO-CH2O* → CHO-CH2O* → CHOH-CH2* → CH2OH-CH2* → CH2OH-CH3* → C2H5OH.
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(This article belongs to the Section Electrocatalysis)
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Open AccessFeature PaperArticle
Synthesis of Propiolic and Butynedioic Acids via Carboxylation of CaC2 by CO2 under Mild Conditions
by
Xiao-Min Zhao, Xiaoteng Zang, Yingzhou Lu, Hong Meng and Chunxi Li
Catalysts 2024, 14(7), 467; https://doi.org/10.3390/catal14070467 - 22 Jul 2024
Abstract
Carbon dioxide (CO2) is a greenhouse gas, and its resource use is vital for carbon reduction and neutrality. Herein, the nucleophilic addition reaction of calcium carbide (CaC2) to CO2 was studied for the first time to synthesize propiolic
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Carbon dioxide (CO2) is a greenhouse gas, and its resource use is vital for carbon reduction and neutrality. Herein, the nucleophilic addition reaction of calcium carbide (CaC2) to CO2 was studied for the first time to synthesize propiolic and butynedioic acids by using CuI or AgNO3 as catalyst, Na2CO3 as additive, and triphenylphosphine as ligand in the presence/absence of a hydrogen donor. The effects of the experimental conditions and intensification approach on the reaction were investigated. The reactivity of CaC2 is closely associated with its synergistic activation by the catalysts, solvent, and external intensification, such as the ultrasound and mechanical force. Ultrasound helps to promote the reaction by enhancing the interfacial mass transfer of CaC2 particulates. Mechanochemistry can effectively promote the reaction, yielding 29.8% of butynedioic acid and 74.8% of propiolic acid after 2 h ball milling at 150 rpm, arising from the effective micronization and interfacial renewal of calcium carbide. The present study sheds a light on the high-value uses of CO2 and CaC2 and is of reference significance for the nucleophilic reaction of CaC2 with other carbonyl compounds.
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(This article belongs to the Special Issue Feature Papers in "Industrial Catalysis" Section)
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One-Pot Phyto-Mediated Synthesis of Fe2O3/Fe3O4 Binary Mixed Nanocomposite Efficiently Applied in Wastewater Remediation by Photo-Fenton Reaction
by
Amr A. Essawy, Tamer H. A. Hasanin, Modather. F. Hussein, Emam F. El Agammy and Abd El-Naby I. Essawy
Catalysts 2024, 14(7), 466; https://doi.org/10.3390/catal14070466 - 20 Jul 2024
Abstract
A binary Fe2O3/Fe3O4 mixed nanocomposite was prepared by phyto-mediated avenue to be suited in the photo-Fenton photodegradation of methylene blue (MB) in the presence of H2O2. XRD and SEM analyses illustrated that
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A binary Fe2O3/Fe3O4 mixed nanocomposite was prepared by phyto-mediated avenue to be suited in the photo-Fenton photodegradation of methylene blue (MB) in the presence of H2O2. XRD and SEM analyses illustrated that Fe2O3 nanoparticles of average crystallite size 8.43 nm were successfully mixed with plate-like aggregates of Fe3O4 with a 15.1 nm average crystallite size. Moreover, SEM images showed a porous morphology for the binary Fe2O3/Fe3O4 mixed nanocomposite that is favorable for a photocatalyst. EDX and elemental mapping showed intense iron and oxygen peaks, confirming composite purity and symmetrical distribution. FTIR analysis displayed the distinct Fe-O assignments. Moreover, the isotherm of the developed nanocomposite showed slit-shaped pores in loose particulates within plate-like aggregates and a mesoporous pore-size distribution. Thermal gravimetric analysis (TGA) indicated the high thermal stability of the prepared Fe2O3/Fe3O4 binary nanocomposite. The optical properties illustrated a narrowing in the band gab (Eg = 2.92 eV) that enabled considerable absorption in the visible region of solar light. Suiting the developed binary Fe2O3/Fe3O4 nanocomposite in the photo-Fenton reaction along with H2O2 supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. The solar-driven photodegradation reactions were conducted and the estimated rate constants were 0.002, 0.0047, and 0.0143 min−1 when using the Fe2O3/Fe3O4 nanocomposite, pure H2O2, and the Fe2O3/Fe3O4/H2O2 hybrid catalyst, respectively. Therefore, suiting the developed binary Fe2O3/Fe3O4 nanocomposite and H2O2 in photo-Fenton reaction supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. After being subjected to four photo-Fenton degradation cycles, the Fe2O3/Fe3O4 nanocomposite catalyst still functioned admirably. Further evaluation of Fe2O3/Fe3O4 nanocomposite in photocatalytic remediation of contaminated water using a mixture of MB and pyronine Y (PY) dyestuffs revealed substantial dye photodegradation efficiencies.
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(This article belongs to the Special Issue Novel Nanocatalysts for Sustainable and Green Chemistry)
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Effect of Support Functionalization on Catalytic Direct Hydrogenation and Catalytic Transfer Hydrogenation of Muconic Acid to Adipic Acid
by
Elisa Zanella, Stefano Franchi, Narmin Jabbarli, Ilaria Barlocco, Marta Stucchi and Carlo Pirola
Catalysts 2024, 14(7), 465; https://doi.org/10.3390/catal14070465 - 19 Jul 2024
Abstract
The liquid-phase hydrogenation of muconic acid (MA) to produce bio-adipic acid (AdA) is a prominent environmentally friendly chemical process, that can be achieved through two distinct methodologies: catalytic direct hydrogenation using molecular hydrogen (H2), or catalytic transfer hydrogenation utilizing a hydrogen
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The liquid-phase hydrogenation of muconic acid (MA) to produce bio-adipic acid (AdA) is a prominent environmentally friendly chemical process, that can be achieved through two distinct methodologies: catalytic direct hydrogenation using molecular hydrogen (H2), or catalytic transfer hydrogenation utilizing a hydrogen donor. In this study, both approaches were explored, with formic acid (FA) selected as the hydrogen source for the latter method. Palladium-based catalysts were chosen for these processes. Metal’s nanoparticles (NPs) were supported on high-temperature heat-treated carbon nanofibers (HHT-CNFs) due to their known ability to enhance the stability of this metal catalyst. To assess the impact of support functionalization on catalyst stability, the HHT-CNFs were further functionalized with phosphorus and oxygen to obtain HHT-P and HHT-O, respectively. In the hydrogenation reaction, catalysts supported on functionalized supports exhibited higher catalytic activity and stability compared to Pd/HHT, reaching an AdA yield of about 80% in less than 2 h in batch reactor. The hydrogen-transfer process also yielded promising results, particularly with the 1%Pd/HHT-P catalyst. This work highlights the efficacy of support functionalization in improving catalyst performance, particularly when formic acid is used as a safer and more cost-effective hydrogen donor in the hydrogen-transfer process.
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(This article belongs to the Section Catalytic Materials)
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Facile Preparation of Attapulgite-Supported Ag-AgCl Composite Photocatalysts for Enhanced Degradation of Tetracycline
by
Xiaojie Zhang, Huiqin Wang and Chenlong Yan
Catalysts 2024, 14(7), 464; https://doi.org/10.3390/catal14070464 - 19 Jul 2024
Abstract
In this study, Ag-AgCl/attapulgite (Ag-AgCl/ATP) composites were synthesized via a direct precipitation method using ATP nanorods as a catalyst supporter. ATP nanorods helped to increase the dispersion of Ag-AgCl particles and broaden the light absorption spectrum, which would also help to increase the
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In this study, Ag-AgCl/attapulgite (Ag-AgCl/ATP) composites were synthesized via a direct precipitation method using ATP nanorods as a catalyst supporter. ATP nanorods helped to increase the dispersion of Ag-AgCl particles and broaden the light absorption spectrum, which would also help to increase the active site of the catalyst to promote the degradation of tetracycline (TC). The photocatalytic activity of the Ag-AgCl/ATP composites was evaluated through the degradation of TC, identifying the loading amount of Ag-AgCl, the concentration of TC, and the reaction temperature as critical factors influencing activity. Specifically, the optimal conditions were observed when the loading of Ag-AgCl was 75%, resulting in a photocatalytic degradation efficiency of 77.65%. Furthermore, the highest degradation efficiency (85.01%) was achieved with a TC concentration of 20 mg/L at 20 °C. Radical trapping experiments suggested that the superoxide anion radical (·O2−) was the primary active species in the degradation process, although hydroxyl radicals (·OH) and holes (h+) also contributed. Reusability tests confirmed that the Ag-AgCl/ATP composites exhibited excellent stability and could be effectively reused.
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(This article belongs to the Special Issue Mineral-Based Composite Catalytic Materials)
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α-Alkylation of Aliphatic Ketones with Alcohols: Base Type as an Influential Descriptor
by
Rasika Mane, Li Hui, Ander Centeno-Pedrazo, Alexandre Goguet, Nancy Artioli and Haresh Manyar
Catalysts 2024, 14(7), 463; https://doi.org/10.3390/catal14070463 - 19 Jul 2024
Abstract
Current global challenges associated with energy security and climate emergency, caused by the combustion of fossil fuels (e.g., jet fuel and diesel), necessitate the accelerated development and deployment of sustainable fuels derived from renewable biomass-based chemical feedstocks. This study focuses on the production
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Current global challenges associated with energy security and climate emergency, caused by the combustion of fossil fuels (e.g., jet fuel and diesel), necessitate the accelerated development and deployment of sustainable fuels derived from renewable biomass-based chemical feedstocks. This study focuses on the production of long-chain (straight and branched) ketones by direct α-alkylation of short chain ketones using both homogenous and solid base catalysts in water. Thus, produced long-chain ketones are fuel precursors and can subsequently be hydrogenated to long-chain alkanes suitable for blending in aviation and liquid transportation fuels. Herein, we report a thorough investigation of the catalytic activity of Pd in combination with, (i) homogenous and solid base additives; (ii) screening of different supports using NaOH as a base additive, and (iii) a comparative study of the Ni and Pd metals supported on layered double oxides (LDOs) in α-alkylation of 2-butanone with 1-propanol as an exemplar process. Among these systems, 5%Pd/BaSO4 with NaOH as a base showed the best results, giving 94% 2-butanone conversion and 84% selectivity to alkylated ketones. These results demonstrated that both metal and base sites are necessary for the selective conversion of 2-butanone to alkylated ketones. Additionally, amongst the solid base additives, Pd/C with 5% Ba/hydrotalcite showed the best result with 51% 2-butanone conversion and 36% selectivity to the alkylated ketones. Further, the screening of heterogenous acid-base catalysts 2.5%Ni/Ba1.2Mg3Al1 exhibited an adequate catalytic activity (21%) and ketone selectivity (47%).
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(This article belongs to the Section Catalysis for Sustainable Energy)
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