Catalysts

4 pages, 169 KB

Open AccessEditorial

Problems of Overpotential Measurements: Editorial to the Special Issue “Electrocatalytic Water Oxidation, 2nd Edition”

by Yurii Geletii

Catalysts 2026, 16(2), 119; https://doi.org/10.3390/catal16020119 - 26 Jan 2026

A total of 12 papers have been published across the Special Issues “Electrocatalytic Water Oxidation,” and “Electrocatalytic Water Oxidation, 2nd Edition [...] Full article

(This article belongs to the Special Issue Electrocatalytic Water Oxidation, 2nd Edition)

16 pages, 9316 KB

Open AccessArticle

Governing the Efficiency of Ni/SiO₂-Al₂O₃ Catalyst for Methane Dry Reforming via Strategic Calcination Conditions

by Dalal A. Alshammari, Ahmed A. Ibrahim, Fekri Abdulraqeb Ahmed Ali, Sara E. AbdElhafez, Maryam EL Marouani, Naglaa A. El-Naggar, Fawaz S. Alharbi, Abdullah A. Alsayed and Ahmed S. Al-Fatesh

Catalysts 2026, 16(2), 118; https://doi.org/10.3390/catal16020118 - 26 Jan 2026

Abstract

This study investigates the improvement of Ni/SiO₂-Al₂O₃ catalysts in the dry reforming of methane (DRM) process by detailed adjustments of calcination temperature (600–900 °C) and duration (1–9 h). N₂ physisorption, H₂-TPR, XRD, TGA, and TEM [...] Read more.

This study investigates the improvement of Ni/SiO₂-Al₂O₃ catalysts in the dry reforming of methane (DRM) process by detailed adjustments of calcination temperature (600–900 °C) and duration (1–9 h). N₂ physisorption, H₂-TPR, XRD, TGA, and TEM show that elevated calcination temperatures result in increased surface roughness and reduced specific surface areas. The present investigation indicates that the ideal calcination parameters are 900 °C and 3 h. This helps the catalyst work better. This condition gave the best initial activity (54% CH₄ conversion and 61% CO₂ conversion) and the best long-term stability and resistance to carbon deposition. Using MATLAB R2025b (ODE45) for kinetic analysis, it was found that these factors have a big effect on activation energy. Shorter calcination of 1 h gave high initial activity, but it quickly lost its effectiveness. On the other hand, a longer calcination time of 9 h made the material more stable but less able to condition convert because it sintered too much. These results show that it is very important to carefully control the conditions of calcination in order to make long-lasting, high-performance catalysts for making syngas. Moreover, a 20-h DRM stability run of the optimum catalyst exhibited nearly constant activity, highlighting its strong structural integrity and superior ability to alleviate rapid coke formation. Full article

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25 pages, 1012 KB

Open AccessReview

Design and Applications of Split G-Quadruplex DNAzymes for Construction of Gated Biosensor

by Raphael I. Adeoye, Dunsin S. Osalaye, Sylvia O. Malomo and Femi J. Olorunniji

Catalysts 2026, 16(2), 117; https://doi.org/10.3390/catal16020117 - 25 Jan 2026

Abstract

Split G-quadruplex DNAzymes offer unique opportunities for building gated biosensors with a wide range of applications. Splitting G4 DNAzymes involves separating guanine tracts in the G-quadruplex DNA sequence into two non-functional sequences that reconstitute into a functional G-quadruplex with peroxidase activity upon hybridisation [...] Read more.

Split G-quadruplex DNAzymes offer unique opportunities for building gated biosensors with a wide range of applications. Splitting G4 DNAzymes involves separating guanine tracts in the G-quadruplex DNA sequence into two non-functional sequences that reconstitute into a functional G-quadruplex with peroxidase activity upon hybridisation of the aptamer probe region within the split system with the target molecule. Several studies have demonstrated the reassembly of split G4 DNAzymes and their applications in the detection of various analytes. This approach offers unique opportunities for modular biosensor construction, target-dependent activation, lack of requirement for labelling, amplification-free high sensitivity, and specificity over traditional G4 sensing. In this review, we explore the strategies of splitting G-quadruplex and their applications in biomedical diagnosis, environmental sensing, food safety monitoring, cell detection, and the integration of the technology with nanomaterials for enhanced stability and sensitivity. We considered the classical intermolecular split strategies that utilise binary probes and intramolecular split systems, which integrate the spacer DNA that allow for single probes as the model G4 sequence. Finally, we explore the current challenges required to develop split G-quadruplex DNAzymes into tools for routine practical applications. Full article

(This article belongs to the Special Issue State-of-the-Art Enzyme Engineering and Biocatalysis in Europe)

16 pages, 3098 KB

Open AccessArticle

Electrocatalytic Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Bis(hydroxymethyl)furan Using CuIr Bimetallic Nanowires

by Chen Chen, Chenhao Yang, Hongke Li, Yiran Liu, Yao Chen and Yunlei Zhang

Catalysts 2026, 16(2), 116; https://doi.org/10.3390/catal16020116 - 25 Jan 2026

Abstract

Electrocatalytic hydrogenation (ECH) represents an environmentally friendly pathway for converting 5-hydroxymethylfurfural (HMF) into the high-value chemical 2,5-bis(hydroxymethyl)furan (BHMF). However, its selectivity and Faradaic efficiency are often constrained by competitive hydrogen evolution at the cathode and insufficient supply of active hydrogen at the surface. [...] Read more.

Electrocatalytic hydrogenation (ECH) represents an environmentally friendly pathway for converting 5-hydroxymethylfurfural (HMF) into the high-value chemical 2,5-bis(hydroxymethyl)furan (BHMF). However, its selectivity and Faradaic efficiency are often constrained by competitive hydrogen evolution at the cathode and insufficient supply of active hydrogen at the surface. To address this challenge, this study developed an Ir-decorated copper oxide nanowire catalyst (denoted as CuIr) featuring a hydrogen-rich adsorption (H_ads) surface. The incorporation of Ir significantly enhances the catalyst’s water dissociation capacity, creating abundant H_ads sources that selectively accelerate HMF hydrogenation while suppressing side reactions. Under a mild applied potential of −0.45 V vs. RHE and a current density of approximately −20 mA cm⁻², the optimal CuIr₄₀ catalyst achieved near-complete conversion of HMF (99%), a BHMF yield of 99%, and a high Faradaic efficiency of 97% within 120 min of electrolysis. Mechanistic studies reveal that this catalytic leap stems from the synergistic functional interaction between Cu and Ir sites in substrate activation and hydrogen supply. This work presents a novel strategy for designing efficient electrocatalysts for biomass hydrogenation by regulating surface H_ads concentration. Full article

(This article belongs to the Special Issue Catalytic Valorization and Utilization of Biomass and Biomass Derivatives)

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27 pages, 823 KB

Open AccessReview

Green Synthesis of Biocatalysts for Sustainable Biofuel Production: Advances, Challenges, and Future Directions

by Ghazala Muteeb, Asmaa Waled Abdelrahman, Mohamed Abdelrahman Mohamed, Youssef Basem, Abanoub Sherif, Mohammad Aatif, Mohd Farhan, Ghazi I. Al Jowf, Anabelle P. Buran-Omar and Doaa S. R. Khafaga

Catalysts 2026, 16(2), 115; https://doi.org/10.3390/catal16020115 - 25 Jan 2026

Abstract

The accelerating global demand for sustainable energy, driven by population growth, industrialization, and environmental concerns, has intensified the search for renewable alternatives to fossil fuels. Biofuels, including bioethanol, biodiesel, biogas, and biohydrogen, offer a viable and practical pathway to reducing net carbon dioxide [...] Read more.

The accelerating global demand for sustainable energy, driven by population growth, industrialization, and environmental concerns, has intensified the search for renewable alternatives to fossil fuels. Biofuels, including bioethanol, biodiesel, biogas, and biohydrogen, offer a viable and practical pathway to reducing net carbon dioxide (CO₂) emissions. Yet, their large-scale production remains constrained by biomass recalcitrance, high pretreatment costs, and the enzyme-intensive nature of conversion processes. Recent advances in enzyme immobilization using magnetic nanoparticles (MNPs), covalent organic frameworks, metal–organic frameworks, and biochar have significantly improved enzyme stability, recyclability, and catalytic efficiency. Complementary strategies such as cross-linked enzyme aggregates, carrier-free immobilization, and site-specific attachment further reduce enzyme leaching and operational costs, particularly in lipase-mediated biodiesel synthesis. In addition to biocatalysis, nanozymes—nanomaterials exhibiting enzyme-like activity—are emerging as robust co-catalysts for biomass degradation and upgrading, although challenges in selectivity and environmental safety persist. Green synthesis approaches employing plant extracts, microbes, and agro-industrial wastes are increasingly adopted to produce eco-friendly nanomaterials and bio-derived supports aligned with circular economy principles. These functionalized materials have demonstrated promising performance in esterification, transesterification, and catalytic routes for biohydrogen generation. Technoeconomic and lifecycle assessments emphasize the need to balance catalyst complexity with environmental and economic sustainability. Multifunctional catalysts, process intensification strategies, and engineered thermostable enzymes are improving productivity. Looking forward, pilot-scale validation of green-synthesized nano- and biomaterials, coupled with appropriate regulatory frameworks, will be critical for real-world deployment. Full article

(This article belongs to the Special Issue Design and Application of Combined Catalysis, 2nd Edition)

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23 pages, 3525 KB

Open AccessReview

Rhodium-Based Electrocatalysts for Ethanol Oxidation Reaction: Mechanistic Insights, Structural Engineering, and Performance Optimization

by Di Liu, Qingqing Lv, Dahai Zheng, Chenhui Zhou, Shuchang Chen, Hongxin Yang, Liwei Chen and Yufeng Zhang

Catalysts 2026, 16(2), 114; https://doi.org/10.3390/catal16020114 - 23 Jan 2026

Abstract

Direct ethanol fuel cells (DEFCs) have gained considerable attention as promising power sources for sustainable energy conversion due to their high energy density, low toxicity, and renewable ethanol feedstock. However, the sluggish ethanol oxidation reaction (EOR) kinetics and the formation of strongly adsorbed [...] Read more.

Direct ethanol fuel cells (DEFCs) have gained considerable attention as promising power sources for sustainable energy conversion due to their high energy density, low toxicity, and renewable ethanol feedstock. However, the sluggish ethanol oxidation reaction (EOR) kinetics and the formation of strongly adsorbed intermediates (e.g., CO*, CH_x*) severely hinder catalytic efficiency and durability. Rhodium (Rh)-based catalysts stand out for their balanced intermediate adsorption, efficient C–C bond cleavage, and superior CO tolerance arising from their unique electronic structure. This review summarizes recent advances in Rh-based EOR catalysts, including monometallic Rh nanostructures, Rh-based alloys, and Rh–support composites. The effects of morphology, alloying, and metal–support interactions on activity, selectivity, and stability are discussed in detail. Strategies for structural and electronic regulation—such as nanoscale design, alloying modulation and interfacial engineering—are highlighted to enhance catalytic performance. Finally, current challenges and future directions are outlined, emphasizing the need for Rh-based catalysts with high activity, selectivity and stability, integrating in situ characterization with theoretical modeling. This work provides insights into the structure–activity relationships of Rh-based catalysts and guidance for designing efficient and durable anode catalysts for practical DEFC applications. Full article

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24 pages, 2940 KB

Open AccessArticle

Preparation of Various Glycoside Hydrolase Enzyme Extracts from Durvillaea antarctica and Evaluation of the Neuroprotective Efficacy

by Wei-Cheng Hsiao, Tien-Chiu Wu, Yong-Han Hong, Mei-Chun Lin, Yi-Wen Chiu, Chieh Kao and Chun-Yung Huang

Catalysts 2026, 16(2), 113; https://doi.org/10.3390/catal16020113 - 23 Jan 2026

Abstract

In this study, three distinct hydrolysates, which are designated Dur-I, Dur-II, and Dur-III, were generated from extrusion-pretreated Durvillaea antarctica biomass by applying viscozyme, cellulase, and α-amylase, respectively. Chemical analyses demonstrated distinct compositional differences among the extracts, whereas FTIR spectra verified the presence of [...] Read more.

In this study, three distinct hydrolysates, which are designated Dur-I, Dur-II, and Dur-III, were generated from extrusion-pretreated Durvillaea antarctica biomass by applying viscozyme, cellulase, and α-amylase, respectively. Chemical analyses demonstrated distinct compositional differences among the extracts, whereas FTIR spectra verified the presence of fucose-containing sulfated polysaccharides. Furthermore, NMR analyses revealed pronounced structural variations among the extracts. To investigate neuroprotective properties of Dur-I, Dur-II, and Dur-III, rotenone (Rot) was added to SH-SY5Y cells that had been pretreated with Dur-I/II/III. Here, flow cytometry was employed to assess changes in mitochondrial membrane potential (MMP), Bcl-2 expression, cytochrome c release, caspase-9, -8, and -3 activation, as well as DNA fragmentation. The protective effect of Dur-I/II/III pretreatment of SH-SY5Y cells on the Rot-induced death process was further investigated using cell cycle and annexin V-fluorescein isothiocyanate (FITC)/PI (propidium iodide) double staining analyses. The results reveal that the Rot-induced apoptotic factors were all recovered by the pretreatment of Dur-I/II/III. Moreover, cell cycle and annexin V-FITC/PI double staining analyses also indicated that Dur-I/II/III were capable of protecting SH-SY5Y cells from Rot-induced cytotoxicity. Therefore, these Dur extracts are considered as good candidates for the prevention and treatment of neurodegeneration induced by oxidative stress. Full article

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15 pages, 3302 KB

Open AccessArticle

Multi-Strategy Catalysis of Mn-TiO₂/TiO₂ Composite Photoanode with Built-In Electric Field to Enhance the Charging Performance of Solar Flow Batteries

by Ping Lu, Yan Xie, Xin Zhou, Wei Lu and Qian Xu

Catalysts 2026, 16(2), 112; https://doi.org/10.3390/catal16020112 - 23 Jan 2026

Abstract

The synthesis of Mn-TiO₂/TiO₂, together with its application as a photoanode for solar flow batteries (SFBs), is reported herein. Both the pure TiO₂ electrode and the Mn-TiO₂/TiO₂ based composite electrode were prepared using the sol–gel [...] Read more.

The synthesis of Mn-TiO₂/TiO₂, together with its application as a photoanode for solar flow batteries (SFBs), is reported herein. Both the pure TiO₂ electrode and the Mn-TiO₂/TiO₂ based composite electrode were prepared using the sol–gel spin-coating technique. The incorporation of a Mn-TiO₂ layer led to the enhancement of the built-in electric field within the composite photoanode. This enhancement not only improved the light-harvesting capability of the photoanode but also suppressed the recombination of charge carriers, consequently enhancing the photocatalytic efficiency. Furthermore, the optimal annealing temperature and the optimum TiO₂ loading were systematically controlled and optimized to maximize the photoelectric conversion efficiency of the composite photoanode. Ultimately, the optimized Mn-TiO₂ composite photoanode was integrated into a monolithic solar flow battery. The results demonstrate that the battery’s photocharging current density reaches 300 μA·cm⁻². The photocharging current density was relatively increased by 150%. Full article

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14 pages, 5865 KB

Open AccessArticle

Microwave Synthesis of Transition Metal (Fe, Co, Ni)-Supported Catalysts for CO₂ Hydrogenation

by Anna A. Strekalova, Anastasiya A. Shesterkina, Kirill A. Beresnev, Petr V. Pribytkov, Gennadiy I. Kapustin, Igor V. Mishin, Leonid M. Kustov and Alexander L. Kustov

Catalysts 2026, 16(1), 111; https://doi.org/10.3390/catal16010111 - 22 Jan 2026

Abstract

To improve the efficiency of CO₂ hydrogenation, it is essential to develop new catalysts as well as new methods of producing them. In our work, we propose a new Fe-, Co-, Cu-containing catalyst preparation technique based on depositing the active component through [...] Read more.

To improve the efficiency of CO₂ hydrogenation, it is essential to develop new catalysts as well as new methods of producing them. In our work, we propose a new Fe-, Co-, Cu-containing catalyst preparation technique based on depositing the active component through urea hydrolysis using microwave heating. We also compare catalysts produced with microwave synthesis to samples obtained through traditional synthesis methods, including impregnation and thermal deposition. The obtained catalysts were characterized by XRD, low-temperature N₂ adsorption, SEM., and UV-VIS methods. The catalytic properties of the catalysts depend not only on the nature of the active component, but also on the preparation method. The best results for CO₂ hydrogenation were achieved with Ni-containing catalysts produced by the impregnation method and microwave synthesis. Full article

(This article belongs to the Special Issue Advances in Microwave-Assisted Catalysis: From Catalytic Materials to Catalytic Reactions)

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22 pages, 5608 KB

Open AccessArticle

ZSM-5 Nanocatalyst from Rice Husk: Synthesis, DFT Analysis, and Au/Pt Modification for Isopropanol Conversion

by Ebtsam K. Alenezy, Sahar A. El-Molla, Karam S. El-Nasser, Ylias Sabri and Ibraheem O. Ali

Catalysts 2026, 16(1), 110; https://doi.org/10.3390/catal16010110 - 22 Jan 2026

Abstract

Silica extracted from rice straw was utilized to synthesize nanoscale ZSM-5 zeolite, which was further modified with platinum (Pt) or gold (Au). The structural properties of the materials were examined using XRD, SEM, and BET analysis, while acidity distribution was determined by in [...] Read more.

Silica extracted from rice straw was utilized to synthesize nanoscale ZSM-5 zeolite, which was further modified with platinum (Pt) or gold (Au). The structural properties of the materials were examined using XRD, SEM, and BET analysis, while acidity distribution was determined by in situ FT-IR through pyridine adsorption. The zeolitic samples were evaluated as catalysts for isopropanol conversion in the temperature range of 150–275 °C. Modification of HZSM-5 with Au and Pt introduced additional active metal sites and enhanced the acidity of the catalyst, thereby lowering the activation energy for dehydration reactions and improving catalytic performance. Both acetone and propene were produced from isopropanol conversion across all catalysts, with oligomerization occurring at temperatures above 200 °C. Among the catalysts, HZSM-5 modified with 4% Pt or 4% Au exhibited superior conversion rates and selectivity to propene, achieving 92% selectivity at 200 °C. The enhanced propylene selectivity and stability of Au/HZSM-5 are associated with preserved medium-strength acid sites, as evidenced by in situ FT-IR pyridine adsorption, particularly the band at 1457 cm⁻¹. Theoretical studies indicated that incorporating noble metals such as Au and Pt enhances the stability of the zeolite structure, which is consistent with the experimental results, suggesting new potential for advanced catalysis and material science applications. Full article

(This article belongs to the Special Issue 15th Anniversary of Catalysts—Industrial Development of Catalytic Materials for the Energetic Transition)

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19 pages, 3198 KB

Open AccessArticle

Interface-Engineered Zn@TiO₂ and Ti@ZnO Nanocomposites for Advanced Photocatalytic Degradation of Levofloxacin

by Ishita Raval, Atindra Shukla, Vimal G. Gandhi, Khoa Dang Dang, Niraj G. Nair and Van-Huy Nguyen

Catalysts 2026, 16(1), 109; https://doi.org/10.3390/catal16010109 - 22 Jan 2026

Abstract

The extensive consumption of freshwater resources and the continuous discharge of pharmaceutical residues pose serious risks to aquatic ecosystems and public health. In this study, pristine ZnO, TiO₂, Zn@TiO₂, and Ti@ZnO nanocomposites were synthesized via a precipitation-assisted solid–liquid interference [...] Read more.

The extensive consumption of freshwater resources and the continuous discharge of pharmaceutical residues pose serious risks to aquatic ecosystems and public health. In this study, pristine ZnO, TiO₂, Zn@TiO₂, and Ti@ZnO nanocomposites were synthesized via a precipitation-assisted solid–liquid interference method and systematically evaluated for the photocatalytic degradation of the antibiotic levofloxacin under UV and visible light irradiation. The structural, optical, and surface properties of the synthesized materials were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), UV–visible diffuse reflectance spectroscopy (UV–DRS), and X-ray photoelectron spectroscopy (XPS). XRD analysis confirmed the crystalline nature of all samples, while SEM images revealed spherical and agglomerated morphologies. Photocatalytic experiments were conducted using a 50-ppm levofloxacin solution with a catalyst dosage of 1 g L⁻¹. Pristine ZnO exhibited limited visible-light activity (33.81%) but high UV-driven degradation (92.98%), whereas TiO₂ showed comparable degradation efficiencies under UV (78.6%) and visible light (78.9%). Notably, Zn@TiO₂ nanocomposites demonstrated superior photocatalytic performance, achieving over 90% and near 70% degradation under both UV and visible light, respectively, while Ti@ZnO composites exhibited less than 60% degradation. The enhanced activity of Zn@TiO₂ is attributed to improved interfacial charge transfer, suppressed electron–hole recombination, and extended light absorption. These findings highlight Zn@TiO₂ nanocomposites as promising photocatalysts for efficient treatment of pharmaceutical wastewater under dual-light irradiation. Full article

(This article belongs to the Special Issue Effect of the Modification of Catalysts on the Catalytic Performance, 3rd Edition)

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18 pages, 9387 KB

Open AccessFeature PaperArticle

Fluorine-Substituted Covalent Organic Framework/Anodized TiO₂ Z-Scheme Heterojunction for Enhanced Photoelectrochemical Hydrogen Evolution

by Yuanyuan Niu, Feng Liu, Ping Li, Hongbin Qi and Bing Sun

Catalysts 2026, 16(1), 108; https://doi.org/10.3390/catal16010108 - 22 Jan 2026

Abstract

A well-defined heterojunction and tailored interface of the photocathode are desired to facilitate the efficient separation and transfer of photogenerated charge carriers for photoelectrochemical (PEC) hydrogen generation. Herein, optimized Z-scheme heterojunction (denoted as F-COF/TiO₂) photoelectrodes were designed and fabricated by solvothermally [...] Read more.

A well-defined heterojunction and tailored interface of the photocathode are desired to facilitate the efficient separation and transfer of photogenerated charge carriers for photoelectrochemical (PEC) hydrogen generation. Herein, optimized Z-scheme heterojunction (denoted as F-COF/TiO₂) photoelectrodes were designed and fabricated by solvothermally growing a F-substituted imine-linked covalent organic framework (F-COF) from 1,3,5-tris(3-fluoro-4-formylphenyl)benzene and 1,4-diaminobenzene on the surface of anodized TiO₂ nanotubes for enhanced PEC hydrogen evolution. The F-COF/TiO₂ heterojunction with photo-deposited Pt species as cocatalysts (Pt@F-COF/TiO₂) revealed higher cathodic photocurrent density, decreased interfacial resistance, and improved onset potential due to the improved charge separation and transfer efficiency at the interface. Both the internal electric field between F-COF and TiO₂, as well as the enhanced photophysical nature of F-COF films, contributed to the efficient interfacial charge separation and transfer. The photo-deposited Pt species and applied bias voltage also demonstrated a synergetic effect on facilitating charge separation and transfer for hydrogen production. The Pt@F-COF/TiO₂ photoelectrode featured an improved PEC hydrogen evolution rate under AM 1.5G simulated sunlight irradiation and a durable PEC hydrogen evolution performance. This study provides valuable insights into the design of heterojunction-based photoelectrodes for efficient solar-driven hydrogen production for sustainable energy applications. Full article

(This article belongs to the Special Issue Multifunctional Metal–Organic Framework Materials as Catalysts)

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8 pages, 1453 KB

Open AccessCommunication

Double-Sided Illuminated Electrospun PAN TiO₂-Cu₂O Membranes for Enhanced CO₂ Photoreduction to Methanol

by Mathieu Grandcolas

Catalysts 2026, 16(1), 107; https://doi.org/10.3390/catal16010107 - 22 Jan 2026

Abstract

Photocatalytic reduction of CO₂ into value-added chemicals offers a sustainable route to mitigate greenhouse gas emissions while producing renewable fuels. However, conventional TiO₂-based systems suffer from limited visible-light activity and inefficient reactor configurations. Here, we developed electrospun polyacrylonitrile (PAN) membranes [...] Read more.

Photocatalytic reduction of CO₂ into value-added chemicals offers a sustainable route to mitigate greenhouse gas emissions while producing renewable fuels. However, conventional TiO₂-based systems suffer from limited visible-light activity and inefficient reactor configurations. Here, we developed electrospun polyacrylonitrile (PAN) membranes embedded with TiO₂-Cu₂O heterojunction nanoparticles and integrated them into a custom crossflow photocatalytic membrane reactor. The reactor employed bifacial illumination using a solar simulator (front) and a xenon/mercury lamp (back), each calibrated to 1 Sun (100 mW·cm⁻²). Membrane morphology was characterized by SEM, and chemical composition was confirmed by XPS. Photocatalytic performance was evaluated in CO₂-saturated 0.5 M potassium bicarbonate solution under continuous flow. The PAN/ TiO₂-Cu₂O membrane exhibited a methanol production rate of approximately 300 μmol·g⁻¹·h⁻¹ under dual-light illumination, outperforming single illumination, PAN-TiO₂, and PAN controls. Enhanced activity is attributed to extended visible-light absorption, improved charge separation at the TiO₂-Cu₂O heterojunction, and optimized photon flux through bifacial illumination. The electrospun architecture provided high surface area and porosity, facilitating CO₂ adsorption and catalyst dispersion. Combining heterojunction engineering with bifacial reactor design significantly improves solar-driven CO₂ conversion. This approach offers a scalable pathway for integrating photocatalysis and membrane technology into sustainable fuel synthesis. Full article

(This article belongs to the Special Issue Advanced Semiconductor Photocatalysts)

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17 pages, 2778 KB

Open AccessArticle

Boosting Toluene Oxidation over Ru-Doped CoMn₂O₄ Spinel Catalysts by Constructing Ru–O–Mn/Co Chains

by Xue Wu, Shiyu Yu, Jian Mei, Bing Liu and Shijian Yang

Catalysts 2026, 16(1), 106; https://doi.org/10.3390/catal16010106 - 21 Jan 2026

Abstract

The development of efficient spinel oxide catalysts for low-temperature oxidation of volatile organic compounds (VOCs) remains an important research objective. In this work, Ru was doped into a CoMn₂O₄ spinel to enhance its catalytic activity toward toluene oxidation and the [...] Read more.

The development of efficient spinel oxide catalysts for low-temperature oxidation of volatile organic compounds (VOCs) remains an important research objective. In this work, Ru was doped into a CoMn₂O₄ spinel to enhance its catalytic activity toward toluene oxidation and the underlying promotion mechanism of Ru doping was systematically investigated. The resulting Ru-CoMn₂O₄ catalyst showed remarkable performance, with T₉₀ reaching approximately 224 °C at a WHSV of 60,000 cm³ g⁻¹ h⁻¹ and nearly 100% CO₂ selectivity above 200 °C. Mechanism studies revealed that the reaction followed both Mars–van Krevelen (MvK) and Eley–Rideal (E–R) pathways. The reaction rates were strongly influenced by the oxidizing capacity of the catalyst, the abundance of highly valent surface species (namely Co³⁺, Mn⁴⁺, and Ru⁴⁺), adsorbed toluene, lattice oxygen, gaseous toluene, and adsorbed oxygen. With Ru doping, new Ru–O–Mn and Ru–O–Co chains formed in the CoMn₂O₄ spinel structure, leading to a moderate enhancement in oxidizing ability and a moderate increase in the concentration of highly valent surface species, adsorbed toluene, and lattice oxygen. Although a slight reduction in adsorbed oxygen was observed, Ru doping significantly boosted the overall toluene oxidation activity of CoMn₂O₄. In summary, Ru-CoMn₂O₄ represented a promising catalyst for the efficient oxidation of VOCs. Full article

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22 pages, 4146 KB

Open AccessArticle

Machine Learning-Guided Inverse Analysis for Optimal Catalytic Pyrolysis Parameters in Hydrogen Production from Biomass

by Vishal V. Persaud, Abderrachid Hamrani, Medeba Uzzi and Norman D. H. Munroe

Catalysts 2026, 16(1), 105; https://doi.org/10.3390/catal16010105 - 21 Jan 2026

Abstract

Catalytic pyrolysis (CP) of biomass is a promising method for producing sustainable hydrogen because lignocellulosic biomass is widely available, renewable, and approximately carbon-neutral. CP of biomass is influenced by complex, interdependent process parameters, making optimization challenging and time-consuming using traditional methods. This study [...] Read more.

Catalytic pyrolysis (CP) of biomass is a promising method for producing sustainable hydrogen because lignocellulosic biomass is widely available, renewable, and approximately carbon-neutral. CP of biomass is influenced by complex, interdependent process parameters, making optimization challenging and time-consuming using traditional methods. This study investigated a two-stage machine learning (ML) framework fortified with Bayesian optimization to enhance hydrogen production from CP. The ML models were used to classify and predict hydrogen yield using a dataset of 306 points with 14 input features. The classification stage identified conditions favorable for good hydrogen yield, while the regression model (second stage) quantitatively predicted hydrogen yield. The random forest classifier and regressor demonstrated superior capabilities, achieving R² scores of 1.0 and 0.8, respectively. The model demonstrated strong agreement with experimental data and effectively captured the key factors driving hydrogen production. Shapley Additive exPlanation (SHAP) identified temperature and catalyst properties (nickel loading) as the most influential parameters. The inverse analysis framework validated the model’s ability to determine optimal conditions for predicting targeted hydrogen yields by comparing it to experimental data reported in the literature. This AI-driven approach provides a scalable and data-efficient tool for optimizing processes in sustainable hydrogen production. Full article

(This article belongs to the Special Issue Explainable AI (XAI) for Industrial Catalysis: Interpretable Machine Learning for Catalyst Design, Optimization, and Process Efficiency)

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22 pages, 2780 KB

Open AccessArticle

A Cascade Process for CO₂ to Methanol Driven by Non-Thermal Plasma: A Techno-Economic Assessment

by Shiwei Qin, Xiangbo Zou, Yunfei Ma, Yunfeng Ma, Zirong Shen, Angjian Wu and Xiaoqing Lin

Catalysts 2026, 16(1), 104; https://doi.org/10.3390/catal16010104 - 21 Jan 2026

Abstract

The non-thermal plasma-driven cascade process for CO₂-to-methanol conversion shows significant potential in the field of green methanol synthesis. This process innovatively couples a plasma activation module with a catalytic synthesis module via a multi-stage pressurization device, establishing an efficient two-step pathway [...] Read more.

The non-thermal plasma-driven cascade process for CO₂-to-methanol conversion shows significant potential in the field of green methanol synthesis. This process innovatively couples a plasma activation module with a catalytic synthesis module via a multi-stage pressurization device, establishing an efficient two-step pathway that converts CO₂ into methanol via a CO intermediate. Such an arrangement establishes an energy conversion system characterized by both low carbon emissions and high efficiency. This work involved an initial technical evaluation employing a custom-built, lab-scale apparatus. The optimum parameters determined through this assessment were a plasma input voltage of 40 V combined with a subsequent reaction temperature of 240 °C. Operation at these specified parameters yielded a CO₂ conversion of 48%, with the methanol selectivity and production rate reaching 40% and 502 g_MeOH

{\cdot kg}_{cat}^{- 1}

·h⁻¹, respectively. Furthermore, industrial-scale process design and scale-up were performed, accompanied by process simulation using Aspen Plus and a subsequent techno-economic evaluation. The results indicate that, compared to the conventional direct CO₂ hydrogenation process, the proposed cascade route can reduce the capital investment by approximately 17%. Full article

(This article belongs to the Special Issue Catalysts for CO₂ Conversions)

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13 pages, 4617 KB

Open AccessFeature PaperArticle

Highly Uniform and Thermal Stable Paper-Structured Catalyst by Using Glass/Mullite Hybrid Fibers as a Matrix for Efficient Soot Combustion

by Hui Tang, Jiateng Hu, Qianqian Yang and Gang Yu

Catalysts 2026, 16(1), 103; https://doi.org/10.3390/catal16010103 - 21 Jan 2026

Abstract

In the present study, glass/ceramic hybrid fibers were chosen as a paper matrix, which effectively balance toughness and high-temperature resistance for soot combustion applications. In order to address the issue of unevenness in the performance of paper-type catalysts caused by the differences in [...] Read more.

In the present study, glass/ceramic hybrid fibers were chosen as a paper matrix, which effectively balance toughness and high-temperature resistance for soot combustion applications. In order to address the issue of unevenness in the performance of paper-type catalysts caused by the differences in the dispersion behavior of glass fibers and ceramic fibers in water, a facile foam-forming technology was proposed. The obtained glass fiber/mullite composite paper with various mass ratios (1:1, 2:1, 3:1, 4:1, and 5:1) exhibit high evenness, and better high-temperature resistance than the pure glass fibers. After impregnating K-Mn active ingredients, 15K5Mn-GFF-3G1C (GF/CF = 3:1) demonstrates high tensile strength, excellent catalytic activity (T50 = 388 °C), reusability (five cycles), and high-temperature stability (800 °C, 12 h). Full article

(This article belongs to the Section Catalytic Materials)

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10 pages, 982 KB

Open AccessArticle

Comparative Kinetic Study of Phenol Degradation Using Free and Alginate-Gel-Entrapped Extract Containing Tyrosinase from Agaricus bisporus

by Saida Leboukh and Hicham Gouzi

Catalysts 2026, 16(1), 102; https://doi.org/10.3390/catal16010102 - 20 Jan 2026

Abstract

The aim of this study was to investigate the biochemical properties of free and immobilized mushroom tyrosinase (EC 1.14.18.1) entrapped in calcium alginate beads for phenol oxidation in a batch system. Tyrosinase activity was determined spectrophotometrically at 400 nm under optimal conditions. The [...] Read more.

The aim of this study was to investigate the biochemical properties of free and immobilized mushroom tyrosinase (EC 1.14.18.1) entrapped in calcium alginate beads for phenol oxidation in a batch system. Tyrosinase activity was determined spectrophotometrically at 400 nm under optimal conditions. The effects of key operational parameters on phenol oxidation kinetics were evaluated for both enzyme systems. The Michaelis–Menten constant (K_M) of the immobilized enzyme (0.94 ± 0.2 mM) was approximately twice that of the free enzyme (0.56 ± 0.04 mM), while its maximum reaction velocity (V_Max = 101.4 ± 2.2 µmol L⁻¹ min⁻¹) decreased by nearly 30-fold (V_Max(App) = 3.63 ± 0.3 µmol L⁻¹ min⁻¹). Immobilization also shifted the optimal pH of the enzyme to pH 6.0. The optimum temperature and activation energy for phenol oxidation were determined as 55 °C and 52.48 kJ/mol for immobilized tyrosinase, whereas they were 45 °C and 39.58 kJ/mol for the free enzyme. The highest level of activity was obtained with alginate beads of 2.6 mm diameter, and the immobilized preparation exhibited enhanced operational stability, completely retaining its initial activity after five reuse cycles. Overall, these findings suggest that mushroom tyrosinase immobilized in alginate beads is a promising system for phenol removal from wastewater. Full article

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10 pages, 1511 KB

Open AccessArticle

Improvements of Both Anode Catalyst Layer and Porous Transport Layer for the Efficient Proton-Exchange Membrane Water Electrolysis

by Zehao Tan, Ruofan Yu, Baoduo Jin, Chen Deng, Zhidong Huang and Liuxuan Luo

Catalysts 2026, 16(1), 101; https://doi.org/10.3390/catal16010101 - 20 Jan 2026

Abstract

In recent years, green hydrogen production via water electrolysis driven by renewable energy sources has garnered increasingly significant attention. Among the various water electrolysis technologies, proton-exchange membrane water electrolysis (PEMWE) distinguishes itself owing to the unique advantages, including the compact architecture, high efficiency, [...] Read more.

In recent years, green hydrogen production via water electrolysis driven by renewable energy sources has garnered increasingly significant attention. Among the various water electrolysis technologies, proton-exchange membrane water electrolysis (PEMWE) distinguishes itself owing to the unique advantages, including the compact architecture, high efficiency, rapid dynamic response, and high purity of the generated hydrogen. The membrane electrode assembly (MEA) serves as the core component of a PEM electrolyzer. And only a high-performance and stable MEA can provide a reliable platform for investigating the mass transport behavior within the porous transport layer (PTL). In this study, the MEA fabrication method was optimized by varying the ionomer-to-carbon (I/C) ratio, coating strategy, and anode Ir mass loading. As a result, the cell voltage was reduced from 1.679 V to 1.645 V at 1.0 A cm⁻², with a small degradation of 1.3% over 70 h of operation. Based on the optimized MEA, the effects of the structure and porosity of PTL on the mass transport behavior were further analyzed. After the PTL parameter optimization, the cell voltage was further reduced to 1.630 V at 1.0 A cm⁻², while a high-speed camera captured bubble dynamics in real time, showing the fast detachment of small oxygen bubbles. The integrated electrochemical and visualization results provide a useful guideline to designing both MEA and PTL for efficient PEMWE. Full article

(This article belongs to the Special Issue Advanced Catalysts for Water Electrolysis)

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