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
Patterns of Formation of Binary Cobalt–Magnesium Oxide Combustion Catalysts of Various Composition
Catalysts 2024, 14(7), 425; https://doi.org/10.3390/catal14070425 - 3 Jul 2024
Abstract
In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. A study of the samples confirmed the phase transition of MgxCo2–xO4 spinels
[...] Read more.
In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. A study of the samples confirmed the phase transition of MgxCo2–xO4 spinels into the corresponding solid solutions at 800–900 °C. The similarity of the formation patterns for different compositions is shown. The rocksalt oxide in low-temperature samples is an anion-modified paracrystalline phase that forms a “true” solid solution only upon spinel decomposition. The TPR profiles of the decomposed Co3O4 spinel show surface Co3O4 peaks and a wide peak corresponding to the well-crystallized CoO, while partial Co3O4 TPR up to 380 °C results in dispersed and amorphous CoO. The high-temperature non-stoichiometric samples are poorly reduced, indicating their low oxygen reactivity. Spinel reoxidation after heat treatment to 1100 °C by calcination at 750 °C showed complete regeneration for MgCo2O4–Co3O4 samples and its absence in case of an excess of MgO relative to stoichiometry.
Full article
(This article belongs to the Special Issue Homogenous and Heterogenous Catalysis in Bioactive Compound Synthesis and Small Molecule Activation)
►
Show Figures
Open AccessArticle
Catalytic Dechlorination of Three Organochlorides by Recyclable Nano-Palladium-Engineered Natural Sponge with Formic Acid
by
Mingyue Liu, Gang Chen, Zhenjun Song, Zhicai He, Aiguo Zhong and Mei Cui
Catalysts 2024, 14(7), 424; https://doi.org/10.3390/catal14070424 - 3 Jul 2024
Abstract
Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen
[...] Read more.
Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen source for the hydrodechlorination of florfenicol (FF), o-chlorophenol (o-CP), and p-chlorophenol (p-CP). Favorable conversion efficiency of FF, o-CP, and p-CP was achieved at 25 °C and atmospheric pressure attributed to the small diameter and high catalytic reactivity of the prepared Pd NPs, in addition to the slight internal mass transfer limitation of the prepared Pd@M-Sponge. High reaction rate constants were obtained even in the conditions of a low molar ratio of HCOOH to p-CP (10:1) and a high concentration of p-CP (500 mg/L). The prepared catalyst also demonstrated superior recyclability without any obvious decrease in catalytic reactivity in 20 successive p-CP dechlorination cycles. This work provides an ideal recyclable and cost-effective catalyst based on renewable and biocompatible natural material for the catalytic hydrodechlorination of chlorinated organic pollutants with formic acid and a new view for the exploration and designing of highly reactive and stable catalysts for hydrodechlorination.
Full article
(This article belongs to the Section Environmental Catalysis)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00424/article_deploy/html/images/catalysts-14-00424-g001-550.jpg?1719978501)
Figure 1
Open AccessArticle
Application of Platinum Nanoparticles Decorating Mesoporous Carbon Derived from Sustainable Source for Hydrogen Evolution Reaction
by
Erik Biehler, Qui Quach and Tarek M. Abdel-Fattah
Catalysts 2024, 14(7), 423; https://doi.org/10.3390/catal14070423 - 2 Jul 2024
Abstract
The perpetually fluctuating economic and environmental climate significantly increases the demand for alternative fuel sources. The utilization of hydrogen gas is a viable option for such a fuel source. Hydrogen is one of the most energy-dense known substances; however, it is unfortunately also
[...] Read more.
The perpetually fluctuating economic and environmental climate significantly increases the demand for alternative fuel sources. The utilization of hydrogen gas is a viable option for such a fuel source. Hydrogen is one of the most energy-dense known substances; however, it is unfortunately also highly volatile, especially in the diatomic gaseous state most commonly used to store it. The utilization of a hydrogen feedstock material such as sodium borohydride (NaBH4) may prove to mitigate this danger. When NaBH4 reacts with water, hydrogen stored within its chemical structure is released. However, the rate of hydrogen release is slow and thus necessitates a catalyst. Platinum nanoparticles were chosen to act as a catalyst for the reaction, and to prevent them from conglomerating, they were embedded in a backbone of mesoporous carbon material (MCM) derived from a sustainable corn starch source. The nanocomposite (Pt-MCM) was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Pt-MCM underwent catalytic testing, revealing that the catalytic activity of the Pt-MCM composite catalysts increased with increasing quantities of sodium borohydride, lower pH levels, and higher temperatures. The activation energy of the catalyzed reaction was found to be 37.7 kJ mol−1. Reusability experiments showed an initial drop off in hydrogen production after the first trial but subsequent stability. This Pt-MCM catalyst’s competitive activation energy and sustainable MCM backbone derived from readily available corn starch make it a promising option for optimizing the hydrogen generation reaction of NaBH4.
Full article
(This article belongs to the Topic Catalysis for Sustainable Chemistry and Energy, 2nd Volume)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00423/article_deploy/html/images/catalysts-14-00423-ag-550.jpg?1719975222)
Graphical abstract
Open AccessArticle
Development of a γ-Al2O3-Based Heterogeneous Fenton-like Catalyst and Its Application in the Advanced Treatment of Maotai-Flavored Baijiu Wastewater
by
Benfu Luo, Yu**g Yan, **yin Li, Fei Guo, Weiwei Huang, ** Yang, Haiyan Ning, Qicheng Kang, Haixing He, Xuanyu Zhou, **ang Zhou, Shijie Wang and Yuhang Liu
Catalysts 2024, 14(7), 422; https://doi.org/10.3390/catal14070422 - 1 Jul 2024
Abstract
Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial
[...] Read more.
Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1.
Full article
(This article belongs to the Section Catalytic Materials)
Open AccessFeature PaperArticle
Effect of the Second-Shell Coordination Environment on the Performance of P-Block Metal Single-Atom Catalysts for the Electrosynthesis of Hydrogen Peroxide
by
Yidi Wu, Yuxiang Zhang and Sen Lin
Catalysts 2024, 14(7), 421; https://doi.org/10.3390/catal14070421 - 30 Jun 2024
Abstract
Hydrogen peroxide (H2O2) is an important chemical with a diverse range of industrial applications in chemical synthesis and medical disinfection. The traditional anthraquinone oxidation process, with high energy consumption and complexity, is being replaced by cost-effective and environmentally friendly
[...] Read more.
Hydrogen peroxide (H2O2) is an important chemical with a diverse range of industrial applications in chemical synthesis and medical disinfection. The traditional anthraquinone oxidation process, with high energy consumption and complexity, is being replaced by cost-effective and environmentally friendly alternatives. In order to explore suitable catalysts for the electrocatalytic synthesis of H2O2, the stability of B,N-doped graphene loaded with various p-block metal (PM) single atoms (i.e., PM-NxBy: x and y represent the number of atoms of N and B, respectively) and the effects of different numbers and positions of B dopants in the second coordination shell on the catalytic performance were studied by density functional theory (DFT) calculations. The results show that Ga-N4B6 and Sb-N4B6 exhibit enhanced stability and 2e− oxygen reduction reaction (ORR) activity and selectivity. Their thermodynamic overpotential η values are 0.01 V, 0.03 V for Ga-N4B6’s two configurations and 0.02 V, 0 V for Sb-N4B6’s two configurations. Electronic structure calculations indicate that the PM single atom adsorbs OOH* intermediates and transfers electrons into them, resulting in the activation of the O-O bond, which facilitates the subsequent hydrogenation reaction. In summary, Sb-N4B6 and Ga-N4B6 exhibit extraordinary 2e− ORR performance, and their predicted activities are comparable to those of known outstanding catalysts (such as PtHg4 alloy). We propose effective strategies on how to enhance the 2e− ORR activities of carbon materials, elucidate the origin of the activity of potential catalysts, and provide insights for the design and development of electrocatalysts that can be used for H2O2 production.
Full article
(This article belongs to the Special Issue Computational Catalysis for Sustainability)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00421/article_deploy/html/images/catalysts-14-00421-g001-550.jpg?1719744506)
Figure 1
Open AccessReview
Photocatalytic Activity of Metal- and Non-Metal-Anchored ZnO and TiO2 Nanocatalysts for Advanced Photocatalysis: Comparative Study
by
Hamad AlMohamadi, Sameer A. Awad, Ashwani Kumar Sharma, Normurot Fayzullaev, Arístides Távara-Aponte, Lincoln Chiguala-Contreras, Abdelfattah Amari, Carlos Rodriguez-Benites, Mohamed A. Tahoon and Hossein Esmaeili
Catalysts 2024, 14(7), 420; https://doi.org/10.3390/catal14070420 - 30 Jun 2024
Abstract
This review article provides useful information on TiO2 and ZnO photocatalysts and their derivatives in removing organic contaminants such as dyes, hydrocarbons, pesticides, etc. Also, the reaction mechanisms of TiO2 and ZnO photocatalysts and their derivatives were investigated. In addition, the
[...] Read more.
This review article provides useful information on TiO2 and ZnO photocatalysts and their derivatives in removing organic contaminants such as dyes, hydrocarbons, pesticides, etc. Also, the reaction mechanisms of TiO2 and ZnO photocatalysts and their derivatives were investigated. In addition, the impact of adding metallic (e.g., Ag, Co, Pt, Pd, Cu, Au, and Ni) and non-metallic (e.g., C, N, O, and S) cocatalysts to their structure on the photodegradation efficiency of organic compounds was thoroughly studied. Moreover, the advantages and disadvantages of various synthesis procedures of ZnO and TiO2 nanocatalysts were discussed and compared. Furthermore, the impact of photocatalyst dosage, photocatalyst structure, contaminant concentration, pH, light intensity and wavelength, temperature, and reaction time on the photodegradation efficiency were studied. According to previous studies, adding metallic and non-metallic cocatalysts to the TiO2 and ZnO structure led to a remarkable enhancement in their stability and reusability. In addition, metallic and non-metallic cocatalysts attached to TiO2 and ZnO demonstrated remarkable photocatalytic efficiency in removing organic contaminants.
Full article
(This article belongs to the Section Photocatalysis)
Open AccessArticle
Photocatalytic, Antimicrobial, and Cytotoxic Efficacy of Biogenic Silver Nanoparticles Fabricated by Bacillus amyloliquefaciens
by
Ahmed M. Eid, Saad El-Din Hassan, Mohammed F. Hamza, Samy Selim, Mohammed S. Almuhayawi, Mohammed H. Alruhaili, Muyassar K. Tarabulsi, Mohammed K. Nagshabandi and Amr Fouda
Catalysts 2024, 14(7), 419; https://doi.org/10.3390/catal14070419 - 30 Jun 2024
Abstract
The biomass filtrate of the endophytic bacterial strain Bacillus amyloliquefaciens Fa.2 was utilized for the eco-friendly production of silver nanoparticles (Ag-NPs). The yellowish-brown color’s optical properties showed a maximum surface plasmon resonance at 415 nm. The morphological and elemental composition analysis reveals the
[...] Read more.
The biomass filtrate of the endophytic bacterial strain Bacillus amyloliquefaciens Fa.2 was utilized for the eco-friendly production of silver nanoparticles (Ag-NPs). The yellowish-brown color’s optical properties showed a maximum surface plasmon resonance at 415 nm. The morphological and elemental composition analysis reveals the formation of spherical shapes with sizes of 5–40 nm, and the Ag ion comprises the major component of the produced Ag-NPs. X-ray diffraction confirmed the crystalline structure, whereas dynamic light scattering reveals the high stability of synthesized Ag-NPs with a polydispersity index of 0.413 and a negative zeta potential value. The photocatalytic experiment showed the efficacy of Ag-NPs to degrade methylene blue with maximum percentages of 73.9 ± 0.5 and 87.4 ± 0.9% under sunshine and UV irradiation, respectively, compared with 39.8% under dark conditions after 210 min. Additionally, the reusability of Ag-NPs was still more active for the fifth run, with a percentage decrease of 11.6% compared with the first run. Interestingly, the biogenic Ag-NPs showed superior antimicrobial activity against different pathogenic Gram-negative bacteria (MIC = 6.25 µg mL−1), Gram-positive bacteria (MIC = 12.5 µg mL−1), and uni- and multicellular fungi (MIC = 12.5 µg mL−1). Moreover, the biosynthesized Ag-NPs could target cancer cells (Pc3 and Mcf7) at low concentrations compared with normal cell (Vero) lines. The IC50 of normal cells is 383.7 ± 4.1 µg mL−1 compared with IC50 Pc3 (2.5 ± 3.5 µg mL−1) and McF7 (156.1 ± 6.8 µg mL−1). Overall, the bacterially synthesized Ag-NPs showed multifunctional features to be used in environmental catalysis and biomedical applications.
Full article
(This article belongs to the Special Issue Applications and New Trends in Catalysts and Photocatalytic Nanomaterials for Environmental Remediation)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00419/article_deploy/html/images/catalysts-14-00419-ag-550.jpg?1719792814)
Graphical abstract
Open AccessEditorial
Nanoparticles in Catalysis
by
Alexander Modestov and Vitaly Grinberg
Catalysts 2024, 14(7), 418; https://doi.org/10.3390/catal14070418 - 29 Jun 2024
Abstract
Nanoparticles (NPs) are defined as objects with dimensions ranging from 10−9 to 10−7 m [...]
Full article
(This article belongs to the Special Issue Nanoparticles in the Catalysis)
Open AccessFeature PaperArticle
Au Supported on Bovine-Bone-Derived Hydroxyapatite Catalyzes CO2 Photochemical Reduction toward Methanol
by
Sergio Arturo Gama-Lara, Alfredo Rafael Vilchis-Néstor, Deysi Amado-Piña and Reyna Natividad
Catalysts 2024, 14(7), 417; https://doi.org/10.3390/catal14070417 - 29 Jun 2024
Abstract
In this work, gold-photo-catalyzed CO2 transformation was conducted and the effect of three variables with two levels was investigated: support (TiO2 and hydroxyapatite from bovine bone (BB)), Au content (5 and 10%) and activation wavelength (254 and 380–700 nm). Reactions were
[...] Read more.
In this work, gold-photo-catalyzed CO2 transformation was conducted and the effect of three variables with two levels was investigated: support (TiO2 and hydroxyapatite from bovine bone (BB)), Au content (5 and 10%) and activation wavelength (254 and 380–700 nm). Reactions were conducted in a stirred tank reactor by bubbling CO2 (9 × 10−3 dm3/min) in 0.1 dm3 of 0.5 M NaOH solution. The catalysts were synthesized using AuCl3, TiO2 and BB. Au nanoparticles were obtained by reduction with Hetheroteca inuloides, thus eliminating calcination and hydrogenation to reduce the gold species. By TEM, the particle size distribution was determined, and the synthesized nanoparticle sizes varied in the range of 9 to 19 nm, depending on the support and Au content. By UV–Vis spectroscopy, the energy band gaps of the prepared materials were 2.18 eV (10% Au/BB), 2.38 eV (5% Au/BB), 2.42 eV (BB), 3.39 eV (5% Au/TiO2), 3.41 eV (10% Au/TiO2) and 3.43 eV for pure TiO2. Methanol and formic and acetic acids were identified during the process. Selectivity toward methanol was found to be improved with the 10% Au/BB catalytic system.
Full article
(This article belongs to the Special Issue Photo-Catalyzed Processes for a Cleaner Environment)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00417/article_deploy/html/images/catalysts-14-00417-g001-550.jpg?1719666261)
Figure 1
Open AccessArticle
New and Facile Preparation Method for Highly Active Iron Oxide Catalysts for CO Oxidation
by
Steffen Schlicher, Roland Schoch, Nils Prinz, Mirijam Zobel and Matthias Bauer
Catalysts 2024, 14(7), 416; https://doi.org/10.3390/catal14070416 - 29 Jun 2024
Abstract
This work presents a new and facile route for the preparation of iron oxide-based catalysts supported on alumina, which enables the targeted synthesis of catalysts with an increased amount of isolated tetrahedrally coordinated iron centers compared to a conventional impregnation procedure, and therefore
[...] Read more.
This work presents a new and facile route for the preparation of iron oxide-based catalysts supported on alumina, which enables the targeted synthesis of catalysts with an increased amount of isolated tetrahedrally coordinated iron centers compared to a conventional impregnation procedure, and therefore leads to an increase in activity for CO oxidation reaction. By a multi-step impregnation–calcination protocol, the catalysts were synthesized with iron loadings of between 1 and 10 wt%, and their catalytic activity was then compared with a 10 wt% loaded catalyst prepared by conventional single impregnation. With a loading of 8 wt%, the presented catalysts showed an improved catalytic activity regarding light-off and full conversion temperatures compared to this reference. Through the application of several analytical methods (PXRD, PDF, DRUVS, SEM, XAFS), the improved catalytic activity can be correlated with an increased amount of isolated iron centers and a significantly reduced fraction of agglomerates or particles.
Full article
(This article belongs to the Special Issue Non-precious Metal Catalysts for Energy and Environment-Related Applications)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00416/article_deploy/html/images/catalysts-14-00416-g001-550.jpg?1719828307)
Figure 1
Open AccessArticle
Investigation of an Ethanol Electroreforming Cell Based on a Pt1Ru1/C Catalyst at the Anode
by
Carmelo Lo Vecchio, Erminia Mosca, Stefano Trocino and Vincenzo Baglio
Catalysts 2024, 14(7), 415; https://doi.org/10.3390/catal14070415 - 29 Jun 2024
Abstract
The production of H2 from renewable sources represents a crucial challenge for the planet’s future to achieve net zero emissions and store renewable energy. A possible alternative to water electrolysis (WE), which requires high potential (E > 1.48 V) to trigger the
[...] Read more.
The production of H2 from renewable sources represents a crucial challenge for the planet’s future to achieve net zero emissions and store renewable energy. A possible alternative to water electrolysis (WE), which requires high potential (E > 1.48 V) to trigger the oxygen evolution reaction (OER), would be alcohol electrochemical reforming (ER), which implies the oxidation of short organic molecules such as methanol or ethanol. In ER, energy must be supplied to the system, but from a thermodynamic point of view, the energy request for the methanol or ethanol oxidation reaction is much lower than that of the OER. To study this process, an in-house 50 wt.% Pt1Ru1/C anodic catalyst was easily synthesized according to the Pt sulphite complex route and the impregnation of a carbon support (Ketjenblack, KB) and a Ru precursor. X-ray diffraction (XRD), X-ray fluorescence (XRF) spectroscopy, and Transmission Electron Microscopy (TEM) were used to characterize the structure, composition, and morphology of the catalyst. It appears that two distinct crystallographic phases of the Pt and Ru nanoparticles were encountered after the synthesis conducted by Ru impregnation. For the electrochemical measurements, ethanol electrooxidation (2 M CH3CH2OH) was studied first in a half cell with a rotating disc electrode (RDE) configuration under acid conditions and then in a direct ethanol electroreforming (or electrolysis) cell, equipped with a proton exchange membrane (PEM) as the electrolyte. The output current density was 0.93 A cm−2 at 1 V and 90 °C in 2 M ethanol. The remarkable current densities obtained in the alcohol electrolyzer at a low voltage are better than the actual state of the art for PEM ethanol ER.
Full article
(This article belongs to the Special Issue Exclusive Papers of the Editorial Board Members and Topical Advisory Panel Members of Catalysts in Section Electrocatalysis)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00415/article_deploy/html/images/catalysts-14-00415-g001-550.jpg?1719644531)
Figure 1
Open AccessFeature PaperArticle
Metal-Catalyzed Thermo-Catalytic Decomposition and Continuous Catalyst Generation
by
Mpila Makiesse Nkiawete and Randy Lee Vander Wal
Catalysts 2024, 14(7), 414; https://doi.org/10.3390/catal14070414 - 29 Jun 2024
Abstract
In this study, metal dusting is utilized to initiate a two-stage thermo-catalytic decomposition (TCD) process. Stage 1 starts with metal-catalyzed TCD, and in stage 2 the metal-catalyzed carbon catalyzes additional TCD. TEM is presented of the early- versus late-stage TCD to qualitatively illustrate
[...] Read more.
In this study, metal dusting is utilized to initiate a two-stage thermo-catalytic decomposition (TCD) process. Stage 1 starts with metal-catalyzed TCD, and in stage 2 the metal-catalyzed carbon catalyzes additional TCD. TEM is presented of the early- versus late-stage TCD to qualitatively illustrate the second-stage TCD by the metal-catalyzed carbons. Corresponding SEM illustrates differences in growth type and surface density between early versus late reaction times, with backscattered imaging differentiating the first- versus second-stage TCD. TGA supports the microscopic inference of a second carbon phase by the presence of an early (low-temperature) reaction peak, characteristic of low-structure or disordered carbon as the second-stage TCD carbon. Raman analysis confirms that the second-stage carbon deposit is more disordered and unstructured, especially at 1000 °C, supported by the ID/IG and La value changes from 0.068 to 0.936 and 65 nm to 4.7 nm, respectively. To further confirm second-stage TCD occurrence upon pre-catalyzed carbons, two carbon blacks are tested. Exposing a combination of edge and basal or exclusively basal sites for the graphitized form, they afford a direct comparison of TCD carbon nanostructure dependence upon the initial carbon catalyst nanostructure. Pre-oxidation of the stainless-steel wool (SSW) prior to TCD is advantageous, accelerating TCD rates and increasing carbon yield relative to the nascent SSW for an equivalent reaction duration.
Full article
(This article belongs to the Section Industrial Catalysis)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00414/article_deploy/html/images/catalysts-14-00414-g001-550.jpg?1719643339)
Figure 1
Open AccessCommunication
A Green Synthesis of 3-Selanyl-Isoflavones via Lipase Mediated Selenylation/Cyclization of Enaminones
by
Wenbo Kan, Yuming Piao, Wenning Song, **aoxuan Chen, Chunyu Wang, Zhi Wang and Lei Wang
Catalysts 2024, 14(7), 413; https://doi.org/10.3390/catal14070413 - 28 Jun 2024
Abstract
Herein, a green biocatalytic approach using lipase as a catalyst has been developed for the synthesis of 3-selanyl-isoflavones through the selenylation/cyclization of 2-hydroxyphenyl enaminones and diphenyl di-selenide under mild conditions. The environmentally friendly method reached high yields of 87–95% in a short time
[...] Read more.
Herein, a green biocatalytic approach using lipase as a catalyst has been developed for the synthesis of 3-selanyl-isoflavones through the selenylation/cyclization of 2-hydroxyphenyl enaminones and diphenyl di-selenide under mild conditions. The environmentally friendly method reached high yields of 87–95% in a short time at 30 °C, with 17 examples of 3-selanyl-isoflavones successfully prepared. Furthermore, we have investigated the possible mechanisms underlying this reaction.
Full article
(This article belongs to the Special Issue Advances in Green Catalysis for Sustainable Organic Synthesis, 2nd Edition)
Open AccessFeature PaperArticle
CO2 Electroreduction by Engineering the Cu2O/RGO Interphase
by
Matteo. Bisetto, Sourav Rej, Alberto Naldoni, Tiziano Montini, Manuela Bevilacqua and Paolo Fornasiero
Catalysts 2024, 14(7), 412; https://doi.org/10.3390/catal14070412 - 28 Jun 2024
Abstract
In the present investigation, Cu2O-based composites were successfully prepared through a multistep method where cubic Cu2O nanoparticles (CU Cu2O) have been grown on Reduced Graphene Oxide (RGO) nanosheets. The structural and morphological properties of the materials have
[...] Read more.
In the present investigation, Cu2O-based composites were successfully prepared through a multistep method where cubic Cu2O nanoparticles (CU Cu2O) have been grown on Reduced Graphene Oxide (RGO) nanosheets. The structural and morphological properties of the materials have been studied through a comprehensive characterization, confirming the coexistence of crystalline Cu2O and RGO. Microscopical imaging revealed the intimate contact between the two materials, affecting the size and the distribution of Cu2O nanoparticles on the support. The features of the improved morphology strongly affected the electrochemical behavior of the composites, increasing the activity and the faradaic efficiencies towards the electrochemical CO2 reduction reaction process. CU Cu2O/RGO 2:1 composite displayed selective CO formation over H2, with higher currents compared to pristine Cu2O (−0.34 mA/cm2 for Cu2O and −0.64 mA/cm2 for CU Cu2O/RGO 2:1 at the voltage of −0.8 vs. RHE and in a CO2 atmosphere) and a faradaic efficiency of 50% at −0.9 V vs. RHE. This composition exhibited significantly higher CO production compared to the pristine materials, indicating a favorable *CO intermediate pathway even at lower voltages. The systematic investigation on the effects of nanostructuration on composition, morphology and catalytic behavior is a valuable solution for the formation of effective interphases for the promotion of catalytic properties providing crucial insights for future catalysts design and applications.
Full article
(This article belongs to the Special Issue In-Depth Study of Electrochemical Reduction Catalysts and Promoters toward Green and Sustainable Processes)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00412/article_deploy/catalysts-14-00412-ag.jpg?1720007685)
Graphical abstract
Open AccessCorrection
Correction: Aldana et al. Nanocomposite PVDF/TiO2 Photocatalytic Membranes for Micropollutant Removal in Secondary Effluent. Catalysts 2024, 14, 109
by
Juan C. Aldana, Marta Pedrosa, Adrián M. T. Silva, Joaquim L. Faria, Juan L. Acero and Pedro M. Álvarez
Catalysts 2024, 14(7), 411; https://doi.org/10.3390/catal14070411 - 28 Jun 2024
Abstract
In the original publication [...]
Full article
(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Catalytic and Photocatalytic Membrane Reactors)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00411/article_deploy/html/images/catalysts-14-00411-g012-550.jpg?1719571144)
Figure 12
Open AccessArticle
Adjacent Reaction Sites of Atomic Mn2O3 and Oxygen Vacancies Facilitate CO2 Activation for Enhanced CH4 Production on TiO2-Supported Nickel-Hydroxide Nanoparticles
by
Praveen Kumar Saravanan, Dinesh Bhalothia, Amisha Beniwal, Cheng-Hung Tsai, Pin-Yu Liu, Tsan-Yao Chen, Hong-Ming Ku and Po-Chun Chen
Catalysts 2024, 14(7), 410; https://doi.org/10.3390/catal14070410 - 28 Jun 2024
Abstract
The catalytic conversion of carbon dioxide (CO2) to methane (CH4) through the “Sabatier reaction”, also known as CO2 methanation, presents a promising avenue for establishing a closed carbon loop. However, the competitive reverse water gas shift (RWGS) reaction
[...] Read more.
The catalytic conversion of carbon dioxide (CO2) to methane (CH4) through the “Sabatier reaction”, also known as CO2 methanation, presents a promising avenue for establishing a closed carbon loop. However, the competitive reverse water gas shift (RWGS) reaction severely limits CH4 production at lower temperatures; therefore, develo** highly efficient and selective catalysts for CO2 methanation is imperative. In this regard, we have developed a novel nanocatalyst comprising atomic scale Mn2O3 species decorated in the defect sites of TiO2-supported Ni-hydroxide nanoparticles with abundant oxygen vacancies (hereafter denoted as NiMn-1). The as-prepared NiMn-1 catalyst initiates the CO2 methanation at a temperature of 523 K and delivers an optimal CH4 production yield of 21,312 mmol g−1 h−1 with a CH4 selectivity as high as ~92% at 573 K, which is 45% higher as compared to its monometallic counterpart Ni-TiO2 (14,741 mmol g−1 h−1). Physical investigations combined with gas chromatography analysis corroborate that the exceptional activity and selectivity of the NiMn-1 catalyst stem from the synergistic cooperation between adjacent active sites on its surface. Specifically, the high density of oxygen vacancies in Ni-hydroxide and adjacent Mn2O3 domains facilitate CO2 activation, while the metallic Ni domains trigger H2 splitting. We envision that the obtained results pave the way for the design of highly active and selective catalysts for CO2 methanation.
Full article
(This article belongs to the Special Issue Catalysis on Stable Molecules (CO2, CO, CH4, N2, NH3) Activation and Their Transformation, 2nd Edition)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00410/article_deploy/html/images/catalysts-14-00410-g001-550.jpg?1719655605)
Figure 1
Open AccessFeature PaperArticle
A Preliminary Assessment of Sorption-Enhanced Methanol Synthesis in a Fluidized Bed Reactor with Selective Addition/Removal of the Sorbent
by
Miguel Menéndez, Raúl Ciércoles, Javier Lasobras, Jaime Soler and Javier Herguido
Catalysts 2024, 14(7), 409; https://doi.org/10.3390/catal14070409 - 28 Jun 2024
Abstract
Methanol synthesis from CO2 can be made in the presence of a sorbent to increase the achievable yield. If the fresh sorbent is continuously fed to a fluidized bed and separated from the catalyst bed by segregation, a steady-state operation can be
[...] Read more.
Methanol synthesis from CO2 can be made in the presence of a sorbent to increase the achievable yield. If the fresh sorbent is continuously fed to a fluidized bed and separated from the catalyst bed by segregation, a steady-state operation can be achieved. The objective of the present work is to provide insight on the suitable operating conditions for such a fluidized bed reactor system. For this, a conventional CuO/ZnO/Al2O3 was selected as the catalyst, and the SiOLITE® zeolite was selected as the sorbent. Different particle sizes were used to be tested in various proportions to perform the fluidized bed segregation study. The fluid dynamics and segregation of the catalyst–sorbent binary mixtures were the most critical points in the development of this proof of concept. A good bed segregation with a mixing index of 0.31 was achieved. This fact favors the correct operation of the system with the continuous addition of adsorbent, which had hardly any catalyst losses during the tests carried out, achieving a loss of 0.005 g/min under optimal conditions. Continuous feeding and removal of sorbent with a low loss of catalyst was observed. Reactor simulations with MATLAB provided promising results, indicating that the addition of sorbent considerably improves the methanol yield under some operating conditions. This makes it more viable for industrial scaling, since it allows us to considerably reduce the pressure used in the methanol synthesis process or to increase the yield per step, reducing the recirculation of unconverted reactants.
Full article
(This article belongs to the Special Issue Fluidizable Catalysts for Novel Chemical Processes)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00409/article_deploy/html/images/catalysts-14-00409-ag-550.jpg?1719564045)
Graphical abstract
Open AccessArticle
Photocatalytic 4-Nitrophenol Reduction by Hydrothermally Synthesized Mesoporous Co- and/or Fe-Substituted Aluminophosphates
by
B. M. Swetha, Rajeev Kumar, Anupama A. V., Sarvesh Kumar, Fei Yan and Balaram Sahoo
Catalysts 2024, 14(7), 408; https://doi.org/10.3390/catal14070408 - 28 Jun 2024
Abstract
Mesoporous cobalt- and/or iron-substituted aluminophosphates were synthesized by a hydrothermal method, followed by pyrolysis and calcination. The substitution of the transition metal elements modified the electronic properties of the samples and the accompanying surface characteristics. The samples showed tunable catalytic activity through the
[...] Read more.
Mesoporous cobalt- and/or iron-substituted aluminophosphates were synthesized by a hydrothermal method, followed by pyrolysis and calcination. The substitution of the transition metal elements modified the electronic properties of the samples and the accompanying surface characteristics. The samples showed tunable catalytic activity through the substitution of Fe and/or Co. We have demonstrated that the light-induced photocatalytic 4-nitrophenol reduction reaction can be enhanced through the substitution of Fe and/or Co in aluminophosphates. The induction time associated with the three different types of samples, observed due to the influence of the substituents, allows us to understand the mechanism of the 4-nitrophenol reduction process in our samples. Our work solves the issue associated with the origin of induction time and the enhancement of the catalytic activity of mesoporous aluminophosphates in the 4-nitrophenol reduction reaction through a controlled modification of the electronic properties.
Full article
(This article belongs to the Section Photocatalysis)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00408/article_deploy/html/images/catalysts-14-00408-g001-550.jpg?1719563439)
Figure 1
Open AccessEditorial
Exclusive Papers of the Editorial Board Members and Topical Advisory Panel Members of Catalysts in Section “Catalysis in Organic and Polymer Chemistry”
by
Kotohiro Nomura, Raffaella Mancuso, Zhengguo Cai, Samuel Dagorne, Moris S. Eisen, Luca Gonsalvi, Martin Kotora, Bun Yeoul Lee, Shaofeng Liu, Luísa Margarida Martins, Takeshi Ohkuma, Armando Pombeiro, Fabio Ragaini, Carl Redshaw, Marc Visseaux, Zongquan Wu, Hiroto Yoshida and Masamichi Ogasawara
Catalysts 2024, 14(7), 407; https://doi.org/10.3390/catal14070407 - 27 Jun 2024
Abstract
Herein, I would like to provide an overview of this Special Issue, published in the Organic and Polymer Chemistry Section of Catalysis, comprising contributions from 18 of the journal’s Editorial Board Members [...]
Full article
(This article belongs to the Special Issue Exclusive Papers of the Editorial Board Members and Topical Advisory Panel Members of Catalysts in Section "Catalysis in Organic and Polymer Chemistry")
Open AccessArticle
Study on Novel SCR Catalysts for Denitration of High Concentrated Nitrogen Oxides and Their Reaction Mechanisms
by
Bo Yu, **ngyu Liu, Shufeng Wu, Heng Yang, Shuran Zhou, Li Yang and Fang Liu
Catalysts 2024, 14(7), 406; https://doi.org/10.3390/catal14070406 - 27 Jun 2024
Abstract
With the rapid development of industrialization, the emission of nitrogen oxides (NOx) has become a global environmental issue. Uranium is the primary fuel used in nuclear power generation. However, the production of uranium, typically based on the uranyl nitrate method, usually
[...] Read more.
With the rapid development of industrialization, the emission of nitrogen oxides (NOx) has become a global environmental issue. Uranium is the primary fuel used in nuclear power generation. However, the production of uranium, typically based on the uranyl nitrate method, usually generates large amounts of nitrogen oxides, particularly NO2, with concentrations in the exhaust gas exceeding 10,000 ppm. High concentrations of nitrogen dioxide are also produced during silver electrolysis processing and the treatment of waste electrolyte solutions. Traditional V-W/TiO2 NH3-SCR catalysts typically exhibit high catalytic activity at temperatures ranging from 300 to 400 °C, under conditions of low NOx concentrations and high gas hourly space velocity. However, their performance is not satisfying when reducing high concentrations of NO2. This study aims to optimize the traditional V-W/TiO2 catalysts to enhance their catalytic activity under conditions of high NO2 concentrations (10,000 ppm) and a wide temperature range (200–400 °C). On the basis of 3 wt% Mo/TiO2, various loadings of V2O5 were selected, and their catalytic activities were tested. Subsequently, the optimal ratios of active component vanadium and additive molybdenum were explored. Simultaneously, do** with WO3 for modification was selected in the V-Mo/TiO2 catalyst, followed by activity testing under the same conditions. The results show that: the NOx conversion rates of all five catalysts increase with temperature at range of 200–400 °C. Excessive loading of MoO3 decreased the catalytic performance, with 5 wt% being the optimal loading. The addition of WO3 significantly enhanced the low-temperature activity of the catalysts. When the loadings of WO3 and MoO3 were both 3 wt%, the catalyst exhibited the best denitrification performance, achieving a NOx conversion rate of 98.8% at 250 °C. This catalyst demonstrates excellent catalytic activity in reducing very high concentration (10,000 ppm) NO2, at a wider temperature range, expanding the temperature range by 50% compared to conventional SCR catalysts. Characterization techniques including BET, XRD, XPS, H2-TPR, and NH3-TPD were employed to further study the evolution of the catalyst, and the promotional mechanisms are explored. The results revealed that the proportion of chemisorbed oxygen (Oα) increased in the WO3-modified catalyst, exhibiting lower V reduction temperatures, which are favorable for low-temperature denitrification activity. NH3-TPD experiments showed that compared to MoOx species, surface WOx species could provide more acidic sites, resulting in stronger surface acidity of the catalyst.
Full article
(This article belongs to the Section Environmental Catalysis)
►▼
Show Figures
![](https://pub.mdpi-res.com/catalysts/catalysts-14-00406/article_deploy/catalysts-14-00406-ag.jpg?1719496046)
Graphical abstract
![Catalysts catalysts-logo](https://pub.mdpi-res.com/img/journals/catalysts-logo.png?8600e93ff98dbf14)
Journal Menu
► ▼ Journal Menu-
- Catalysts Home
- Aims & Scope
- Editorial Board
- Reviewer Board
- Topical Advisory Panel
- Instructions for Authors
- Special Issues
- Topics
- Sections & Collections
- Article Processing Charge
- Indexing & Archiving
- Editor’s Choice Articles
- Most Cited & Viewed
- Journal Statistics
- Journal History
- Journal Awards
- Society Collaborations
- Conferences
- Editorial Office
Journal Browser
► ▼ Journal BrowserHighly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Catalysts, Coatings, Crystals, Energies, Materials, Nanomaterials
Interfacial Bonding Design and Applications in Structural and Functional Materials
Topic Editors: Junlei Qi, Pengcheng Wang, Yaotian YanDeadline: 20 July 2024
Topic in
Energies, Catalysts, Fermentation, Processes, Waste
Valorizing Waste through Thermal and Biological Processes for Sustainable Energy Production
Topic Editors: Margarida Gonçalves, Cândida VilarinhoDeadline: 31 August 2024
Topic in
Cancers, Catalysts, Current Oncology, Plasma, Sci
Advances in Low-Temperature Plasma Cancer Therapy
Topic Editors: Michael Keidar, Li Lin, Dayun YanDeadline: 20 September 2024
Topic in
Catalysts, Materials, Nanomaterials, Polymers, Sustainability
Synthesis, Characterization and Performance of Materials for a Sustainable Future, 2nd Volume
Topic Editors: John Vakros, Evroula Hapeshi, Catia Cannilla, Giuseppe Bonura, George Z. KyzasDeadline: 30 September 2024
![loading...](https://pub.mdpi-res.com/img/loading_circle.gif?9a82694213036313?1719920548)
Conferences
Special Issues
Special Issue in
Catalysts
Heterogeneous Catalysis and Advanced Oxidation Processes (AOP) for Environmental Protection (VOCs Oxidation, Air and Water Purification), 2nd Edition
Guest Editor: Roberto FiorenzaDeadline: 5 July 2024
Special Issue in
Catalysts
Advancement in Gas Adsorption Capacity, Optical and Catalytic Applications of Supramolecular Systems or Hybrid Materials
Guest Editors: Luca Spitaleri, Vincenzo PatamiaDeadline: 10 July 2024
Special Issue in
Catalysts
Surfaces and Interfaces in Biocatalysis
Guest Editor: B. Lesiak-OrłowskaDeadline: 31 July 2024
Special Issue in
Catalysts
Advancement in Photocatalysis for Environmental Applications
Guest Editors: Sikai Zhao, Yanbai ShenDeadline: 8 August 2024
Topical Collections
Topical Collection in
Catalysts
Photocatalytic Water Splitting
Collection Editors: Weilong Shi, Guigao Liu
Topical Collection in
Catalysts
Catalytic Conversion of Biomass to Bioenergy
Collection Editors: Sergio Nogales Delgado, Juan Félix González, Simona M. Coman
Topical Collection in
Catalysts
Nanocatalysis towards Energy Transition and Environmental Sustainability
Collection Editors: Michalis Konsolakis, Sónia Carabineiro