Catalysts

14 pages, 1928 KiB

Open AccessArticle

Ultraviolet Photocatalytic Performance of ZnO Nanorods Selectively Deposited with Bi₂O₃ Quantum Dots

by Baohui Lou, Chi Zhang, Xianhao Wu, Ying Liu, Xiangdong Feng, Feipeng Huang, Bowen Zhao and Zhengwang Zhu

Catalysts 2025, 15(7), 695; https://doi.org/10.3390/catal15070695 - 21 Jul 2025

Viewed by 360

Abstract

A strong interaction between Bi³⁺ and ZnO was used to successfully sensitize ZnO nanorods with quantum dots (QDs) of Bi₂O₃ through three different strategies. Although the Bi₂O₃ QDs had similar particle size distributions, their photocatalytic performance [...] Read more.

A strong interaction between Bi³⁺ and ZnO was used to successfully sensitize ZnO nanorods with quantum dots (QDs) of Bi₂O₃ through three different strategies. Although the Bi₂O₃ QDs had similar particle size distributions, their photocatalytic performance varied significantly, prompting the investigation of factors beyond particle size. The study revealed that the photochemical method selectively deposited Bi₂O₃ QDs onto electron-rich ZnO sites, providing a favorable pathway for efficient electron–hole separation and transfer. Consequently, abundant h⁺ and ·OH radicals were generated, which effectively degraded Rhodamine B (RhB). As demonstrated in the RhB degradation experiments, the Bi₂O₃/ZnO nanorod catalyst achieved an 89.3% degradation rate within 120 min, significantly outperforming catalysts with other morphologies. The photoluminescence (PL) and time-resolved photoluminescence (TRPL) results indicated that the Bi₂O₃/ZnO heterostructure constructed an effective interface to facilitate the spatial separation of photogenerated charge carriers, which effectively prolonged their lifetime. The electron paramagnetic resonance (EPR) results confirmed that the ·OH radicals played a key role in the degradation process. Full article

(This article belongs to the Special Issue Advanced Catalytic Processes for Wastewater Treatment)

► Show Figures

Graphical abstract

18 pages, 4038 KiB

Open AccessArticle

Highly Efficient and Stable Ni-Cs/TS-1 Catalyst for Gas-Phase Propylene Epoxidation with H₂ and O₂

by Ziyan Mi, Huayun Long, Yuhua Jia, Yue Ma, Cuilan Miao, Yan Xie, Xiaomei Zhu and Jiahui Huang

Catalysts 2025, 15(7), 694; https://doi.org/10.3390/catal15070694 - 21 Jul 2025

Viewed by 444

Abstract

The development of non-noble metal catalysts for gas-phase propylene epoxidation with H₂/O₂ remains challenging due to their inadequate activity and stability. Herein, we report a Cs⁺-modified Ni/TS-1 catalyst (9%Ni-Cs/TS-1), which exhibits unprecedented catalytic performance, giving a state-of-the-art PO [...] Read more.

The development of non-noble metal catalysts for gas-phase propylene epoxidation with H₂/O₂ remains challenging due to their inadequate activity and stability. Herein, we report a Cs⁺-modified Ni/TS-1 catalyst (9%Ni-Cs/TS-1), which exhibits unprecedented catalytic performance, giving a state-of-the-art PO formation rate of 382.9 g_PO·kg_cat⁻¹·h⁻¹ with 87.8% selectivity at 200 °C. The catalyst stability was sustainable for 150 h, far surpassing reported Ni-based catalysts. Ni/TS-1 exhibited low catalytic activity. However, the Cs modification significantly enhanced the performance of Ni/TS-1. Furthermore, the intrinsic reason for the enhanced performance was elucidated by multiple techniques such as XPS, N₂ physisorption, TEM, ²⁹Si NMR, NH₃-TPD-MS, UV–vis, and so on. The findings indicated that the incorporation of Cs⁺ markedly boosted the reduction of Ni, enhanced Ni⁰ formation, strengthened Ni-Ti interactions, reduced acid sites to inhibit PO isomerization, improved the dispersion of Ni nanoparticles, reduced particle size, and improved the hydrophobicity of Ni/TS-1 to facilitate propylene adsorption/PO desorption. The 9%Ni-Cs/TS-1 catalyst demonstrated exceptional performance characterized by a low cost, high activity, and long-term stability, offering a viable alternative to Au-based systems. Full article

(This article belongs to the Special Issue Applications of Catalysis in Organic Chemistry: Sustainable Catalysts for Sustainable Processes)

► Show Figures

Graphical abstract

27 pages, 8396 KiB

Open AccessArticle

Biosynthesis of Zinc Oxide Nanostructures Using Leaf Extract of Azadirachta indica: Characterizations and In Silico and Nematicidal Potentials

by Gulrana Khuwaja, Anis Ahmad Chaudhary, Abadi M. Mashlawi, Abdullah Ali Alamri, Faris Alfifi, Kahkashan Anjum, Md Shamsher Alam, Mohammad Intakhab Alam, Syed Kashif Ali, Nadeem Raza, Mohamed A. M. Ali and Mohd Imran

Catalysts 2025, 15(7), 693; https://doi.org/10.3390/catal15070693 - 21 Jul 2025

Viewed by 527

Abstract

Biosynthesized ZnO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible (UV-vis) spectroscopy, and Fourier transform–infrared (FT-IR) spectroscopy. XRD confirmed a hexagonal wurtzite phase with an average crystallite size of 36.44 nm, while UV-vis spectroscopy showed [...] Read more.

Biosynthesized ZnO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible (UV-vis) spectroscopy, and Fourier transform–infrared (FT-IR) spectroscopy. XRD confirmed a hexagonal wurtzite phase with an average crystallite size of 36.44 nm, while UV-vis spectroscopy showed a distinct absorption peak at 321 nm. The Zeta potential of the ZnO nanostructures was −24.28 mV, indicating high stability in suspension, which is essential for their dispersion and functionality in biological and environmental applications. The nematicidal activity of ZnO was evaluated in vitro at concentrations of 150, 300, 450, and 600 ppm, with the highest concentration achieving 75.71% mortality of second-stage juveniles (J2s) after 72 h. The calculated LC₅₀ values for the treatments were 270.33 ppm at 72 h. Additionally, molecular docking studies indicated significant interactions between the ZnO nanostructures and nematode proteins, HSP-90 and ODR1, supporting their potential nematicidal mechanism. This research highlights the effectiveness of neem leaf extract-mediated ZnO nanostructures as an eco-friendly, sustainable alternative for nematode control, presenting a promising solution for agricultural pest management. Full article

(This article belongs to the Special Issue (Bio)nanomaterials in Catalysis)

► Show Figures

Figure 1

17 pages, 2890 KiB

Open AccessReview

Catalytic Ozonation for Reverse Osmosis Concentrated Water Treatment: Recent Advances in Different Industries

by Siqi Chen, Yun Gao, Wenquan Sun, Jun Zhou and Yongjun Sun

Catalysts 2025, 15(7), 692; https://doi.org/10.3390/catal15070692 - 20 Jul 2025

Viewed by 442

Abstract

Reverse osmosis (RO) concentrated water can be effectively treated with catalytic ozone oxidation technology, an effective advanced oxidation process. In order to provide a thorough reference for the safe treatment and reuse of RO concentrated water, this paper examines the properties of RO [...] Read more.

Reverse osmosis (RO) concentrated water can be effectively treated with catalytic ozone oxidation technology, an effective advanced oxidation process. In order to provide a thorough reference for the safe treatment and reuse of RO concentrated water, this paper examines the properties of RO concentrated water, such as its high salt content, high levels of organic pollutants, and low biochemistry. It also examines the mechanism of its role in treating RO concentrated water and combs through its applications in municipal, petrochemical, coal chemical, industrial parks, and other industries. The study demonstrates that ozone oxidation technology can efficiently eliminate the organic matter that is difficult to break down in RO concentrated water and lower treatment energy consumption; however, issues with free radical inhibitor interference, catalyst recovery, and stability still affect its use. Future research into multi-technology synergistic processes, the development of stable and effective non-homogeneous catalysts, and the promotion of their use at the “zero discharge” scale for industrial wastewater are all imperative. Full article

(This article belongs to the Special Issue State-of-the-Art of Heterostructured Photocatalysts)

► Show Figures

Graphical abstract

14 pages, 7478 KiB

Open AccessArticle

Constructing a Ta₃N₅/Tubular Graphitic Carbon Nitride Van Der Waals Heterojunction for Enhanced Photocatalytic Hydrogen Production

by Junbo Yu, Guiming Ba, Fuhong Bi, Huilin Hu, Jinhua Ye and Defa Wang

Catalysts 2025, 15(7), 691; https://doi.org/10.3390/catal15070691 - 20 Jul 2025

Viewed by 419

Abstract

Constructing a heterojunction is considered one of the most effective strategies for enhancing photocatalytic activity. Herein, we employ Ta₃N₅ and tubular graphitic carbon nitride (TCN) to construct a Ta₃N₅/TCN van der Waals heterojunction via electrostatic self-assembly [...] Read more.

Constructing a heterojunction is considered one of the most effective strategies for enhancing photocatalytic activity. Herein, we employ Ta₃N₅ and tubular graphitic carbon nitride (TCN) to construct a Ta₃N₅/TCN van der Waals heterojunction via electrostatic self-assembly for enhanced photocatalytic H₂ production. SEM and TEM results show that Ta₃N₅ particles (~300 nm in size) are successfully anchored onto the surface of TCN. The light absorption capability of the Ta₃N₅/TCN heterojunction is between those of Ta₃N₅ and TCN. The strong interaction between Ta₃N₅ and TCN with different energy structures (Fermi levels) by van der Waals force renders the formation of an interfacial electric field to drive the separation and transfer of photogenerated charge carriers in the Ta₃N₅/TCN heterojunction, as evidenced by the photoluminescence (PL) and photoelectrochemical (PEC) characterization results. Consequently, the optimal Ta₃N₅/TCN heterojunction exhibits a remarkable H₂ production rate of 12.73 mmol g⁻¹ h⁻¹ under visible light irradiation, which is 3.3 and 16.8 times those of TCN and Ta₃N₅, respectively. Meanwhile, the cyclic experiment demonstrates excellent stability of the Ta₃N₅/TCN heterojunction upon photocatalytic reaction. Notably, the photocatalytic performance of 15-TaN/TCN outperforms the most previously reported CN-based and Ta₃N₅-based heterojunctions for H₂ production. This work provides a new avenue for the rational design of CN-based van der Waals heterojunction photocatalysts with enhanced photocatalytic activity. Full article

(This article belongs to the Special Issue Innovative Catalytic and Photocatalytic Systems for Environmental Remediation, 2nd Edition)

► Show Figures

Figure 1

18 pages, 2171 KiB

Open AccessReview

Mechanochemical and Transition-Metal-Catalyzed Reactions of Alkynes

by Lifen Peng, Zhiling Zou, Ting Wang, Xirong Liu, Hui Li, Zhiwen Yuan, Chunling Zeng, Xinhua Xu, Zilong Tang and Guofang Jiang

Catalysts 2025, 15(7), 690; https://doi.org/10.3390/catal15070690 - 17 Jul 2025

Viewed by 792

Abstract

Mechanochemical and transition-metal-catalyzed reactions of alkynes, exhibiting significant advantages like short reaction time, solvent-free, high yield and good selectivity, were considered to be green and sustainable pathways to access functionalized molecules and obtained increasing attention due to the superiorities of mechanochemical processes and [...] Read more.

Mechanochemical and transition-metal-catalyzed reactions of alkynes, exhibiting significant advantages like short reaction time, solvent-free, high yield and good selectivity, were considered to be green and sustainable pathways to access functionalized molecules and obtained increasing attention due to the superiorities of mechanochemical processes and the reactivities of alkynes. The ball milling and CuI-catalyzed Sonogashira coupling of alkyne and aryl iodide avoided the use of common palladium catalysts. The mechanochemical Rh(III)- and Au(I)-catalyzed C–H alkynylations of indoles formed the 2-alkynylated and 3-alkynylated indoles selectively. The mechanochemical and copper-catalyzed azide-alkyne cycloaddition (CuAAC) between alkynes and azides were developed to synthesize 1,2,3-triazoles. Isoxazole could be formed through ball-milling-enabled and Ru-promoted cycloaddition of alkyne and hydroxyimidel chloride. In this review, the generation of mechanochemical and transition-metal-catalyzed reactions of alkynes was highlighted. Firstly, the superiority and application of transition-metal-catalyzed reactions of alkynes were briefly introduced. After presenting the usefulness of green chemistry and mechanochemical reactions, mechanochemical and transition-metal-catalyzed reactions of alkynes were classified and demonstrated in detail. Based on different kinds of reactions of alkynes, mechanochemical and transition-metal-catalyzed coupling, cycloaddition and alkenylation reactions were summarized and the proposed reaction mechanisms were disclosed if available. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis, 2nd Edition)

► Show Figures

Scheme 1

32 pages, 5470 KiB

Open AccessFeature PaperReview

Progress and Reaction Mechanism of Co-Based Catalysts in the Selective Hydrogenation of α,β-Unsaturated Aldehydes

by Haixiang Shi, Jianming Xu, Xuan Luo and Zuzeng Qin

Catalysts 2025, 15(7), 689; https://doi.org/10.3390/catal15070689 - 17 Jul 2025

Viewed by 432

Abstract

In recent years, Co-based catalysts have attracted considerable attention in research on selective hydrogenation reactions because of their mild activities and favorable selectivities for producing intermediate products, especially in the selective hydrogenation of α,β-unsaturated aldehydes (UAL). However, the low activity of Co-based catalysts [...] Read more.

In recent years, Co-based catalysts have attracted considerable attention in research on selective hydrogenation reactions because of their mild activities and favorable selectivities for producing intermediate products, especially in the selective hydrogenation of α,β-unsaturated aldehydes (UAL). However, the low activity of Co-based catalysts for activating hydrogen limits their application in industry, and the diversity of forms and electronic states of Co-based catalysts also leads to the development of complex products and hydrogenation mechanisms at Co active sites. This review provides a comprehensive and systematic overview of recent progress in the selective hydrogenation of UAL over Co-based catalysts, where the preparation methods, hydrogenation properties, and UAL hydrogenation mechanisms of Co-based catalysts are carefully discussed. The influences of nanosize effects, electronic effects, and coordination effects on Co metal and Co oxides are investigated. In addition, the different reaction mechanisms at Co active sites are compared, and their strengths and weaknesses for C=O hydrogenation are further proposed. Finally, the outlook and challenges for the future development of Co-based hydrogenation catalysts are highlighted. Full article

(This article belongs to the Special Issue Environmentally Friendly Catalysis for Green Future)

► Show Figures

Graphical abstract

29 pages, 3303 KiB

Open AccessArticle

Synergetic Effect of Tin and Potassium as Modifying Additives on Rhodium Catalysts in the Process of Selective Dehydrogenation of Associated Petroleum Gas

by Kairat A. Kadirbekov, Mojtaba Mirzaeian, Nurdaulet A. Buzayev and Almaz K. Kadirbekov

Catalysts 2025, 15(7), 688; https://doi.org/10.3390/catal15070688 - 17 Jul 2025

Viewed by 396

Abstract

This paper presents the results of an investigation into the catalytic activity and selectivity of rhodium-based catalysts supported on natural zeolite clinoptilolite from the Shankanai field (Kazakhstan) in the dehydrogenation of light alkanes from associated petroleum gas (APG). Three modifications of the catalyst [...] Read more.

This paper presents the results of an investigation into the catalytic activity and selectivity of rhodium-based catalysts supported on natural zeolite clinoptilolite from the Shankanai field (Kazakhstan) in the dehydrogenation of light alkanes from associated petroleum gas (APG). Three modifications of the catalyst have been studied: basic 1%Rh/HCpt, modified with tin 1%Rh/10%SnO/HCpt, and combined with additives of tin and potassium 1%Rh/10%SnO/5%K₂O/HCpt. It has been shown that the addition of tin contributes to increased thermal stability and a decreased coking rate, while the addition of potassium suppresses side reactions (cracking and isomerization), increasing the selectivity for olefins. The highest yield of olefins (~30%) is achieved with the 1%Rh/10%SnO/5%K₂O/HCpt catalyst in the presence of water vapor. Using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), improved distribution of active components and reduced catalyst deactivation have been confirmed. The obtained data demonstrate the potential of the developed systems for the efficient processing of APG and the selective synthesis of olefins. Full article

(This article belongs to the Section Catalysis for Sustainable Energy)

► Show Figures

Graphical abstract

19 pages, 4090 KiB

Open AccessArticle

The Behavior of Divalent Metals in Double-Layered Hydroxides as a Fenton Bimetallic Catalyst for Dye Decoloration: Kinetics and Experimental Design

by Edgar Oswaldo Leyva Cruz, Diana Negrete Godínez, Deyanira Angeles-Beltrán and Refugio Rodríguez-Vázquez

Catalysts 2025, 15(7), 687; https://doi.org/10.3390/catal15070687 - 16 Jul 2025

Viewed by 565

Abstract

This study investigates the influence of divalent metals—(Mg(II), Co(II), and Ni(II)) in layered double hydroxides (LDHs), with a constant trivalent Fe(III) component—on the decoloration of crystal violet and methyl blue dyes via a Fenton-type oxidation reaction. The catalysts, synthesized by co-precipitation and hydrothermal [...] Read more.

This study investigates the influence of divalent metals—(Mg(II), Co(II), and Ni(II)) in layered double hydroxides (LDHs), with a constant trivalent Fe(III) component—on the decoloration of crystal violet and methyl blue dyes via a Fenton-type oxidation reaction. The catalysts, synthesized by co-precipitation and hydrothermal treatment, were tested in both hydroxide and oxide forms under varying agitation conditions (0 and 280 rpm). A 2² × 3 factorial design was used to analyze the effect of the divalent metal type, catalyst phase, and stirring. The Mg/Fe oxide, with the highest BET surface area (144 m²/g) and crystallite size (59.7 nm), showed superior performance—achieving up to 98% decoloration of crystal violet and 97% of methyl blue within 1 h. The kinetic analysis revealed pseudo-second-order and pseudo-first-order fits for crystal violet and methyl blue, respectively. These findings suggest that LDH-based catalysts provide a fast, low-cost, and effective option for dye removal in aqueous systems. Full article

(This article belongs to the Section Environmental Catalysis)

► Show Figures

Graphical abstract

16 pages, 8156 KiB

Open AccessFeature PaperArticle

The Development of Ni-Al Aerogel-Based Catalysts via Supercritical CO₂ Drying for Photocatalytic CO₂ Methanation

by Daniel Estevez, Haritz Etxeberria and Victoria Laura Barrio

Catalysts 2025, 15(7), 686; https://doi.org/10.3390/catal15070686 - 16 Jul 2025

Viewed by 496

Abstract

The conversion of CO₂ into CH₄ through the Sabatier reaction is one of the key processes that can reduce CO₂ emissions into the atmosphere. This work aims to develop Ni-Al aerogel-based thermo-photocatalysts with large specific surface areas prepared using a [...] Read more.

The conversion of CO₂ into CH₄ through the Sabatier reaction is one of the key processes that can reduce CO₂ emissions into the atmosphere. This work aims to develop Ni-Al aerogel-based thermo-photocatalysts with large specific surface areas prepared using a sol–gel method and subsequent supercritical drying in CO₂. Different Al/Ni molar ratios were selected for the development of the catalysts, characterized using ICP-OES, N₂ adsorption–desorption isotherms, XRD, H₂-TPR, TEM, UV-Vis DRS, and XPS techniques. Thermo-photocatalytic activity tests were performed in a photoreactor with two different light sources (λ = 365 nm, λ = 470 nm) at a temperature range from 300 °C to 450 °C and a pressure of 10 bar. The catalyst with the highest Ni loading (AG 1/3) produced the best catalytic results, reaching CO₂ conversion and CH₄ selectivity levels of 82% and 100%, respectively, under visible light at 450 °C. In contrast, the catalysts with the lowest nickel loading produced the lowest results, most likely due to their low amounts of active Ni. These results suggest that supercritical drying is an efficient method for developing active thermo-photocatalysts with high Ni dispersion, suitable for Sabatier reactions under mild reaction conditions. Full article

(This article belongs to the Special Issue Advancements in Photocatalysis for Environmental Applications)

► Show Figures

Graphical abstract

22 pages, 7389 KiB

Open AccessArticle

FeCo-LDH/CF Cathode-Based Electrocatalysts Applied to a Flow-Through Electro-Fenton System: Iron Cycling and Radical Transformation

by Heng Dong, Yuying Qi, Zhenghao Yan, Yimeng Feng, Wenqi Song, Fengxiang Li and Tao Hua

Catalysts 2025, 15(7), 685; https://doi.org/10.3390/catal15070685 - 15 Jul 2025

Viewed by 367

Abstract

In this investigation, a hierarchical FeCo-layered double hydroxide (FeCo-LDH) electrochemical membrane material was prepared by a simple in situ hydrothermal method. The prepared material formed a 3D honeycomb-structured FeCo-LDH-modified carbon felt (FeCo-LDH/CF) catalytic layer with uniform open pores on a CF substrate with [...] Read more.

In this investigation, a hierarchical FeCo-layered double hydroxide (FeCo-LDH) electrochemical membrane material was prepared by a simple in situ hydrothermal method. The prepared material formed a 3D honeycomb-structured FeCo-LDH-modified carbon felt (FeCo-LDH/CF) catalytic layer with uniform open pores on a CF substrate with excellent catalytic activity and was served as the cathode in a flow-through electro-Fenton (FTEF) reactor. The electrocatalyst demonstrated excellent treatment performance (99%) in phenol simulated wastewater (30 mg L⁻¹) under the optimized operating conditions (applied voltage = 3.5 V, pH = 6, influent flow rate = 15 mL min⁻¹) of the FTEF system. The high removal rate could be attributed to (i) the excellent electrocatalytic oxidation performance and low interfacial charge transfer resistance of the FeCo-LDH/CF electrode as the cathode, (ii) the ability of the synthesized FeCo-LDH to effectively promote the conversion of H₂O₂ to •OH under certain conditions, and (iii) the flow-through system improving the mass transfer efficiency. In addition, the degradation process of pollutants within the FTEF system was additionally illustrated by the •OH dominant ROS pathway based on free radical burst experiments and electron paramagnetic resonance tests. This study may provide new insights to explore reaction mechanisms in FTEF systems. Full article

(This article belongs to the Special Issue Environmentally Friendly Catalysis for Green Future)

► Show Figures

Figure 1

6 pages, 170 KiB

Open AccessEditorial

Recent Advances in Energy-Related Materials—Special Issue Preface

by Virginija Kepenienė and Loreta Tamašauskaitė-Tamašiūnaitė

Catalysts 2025, 15(7), 684; https://doi.org/10.3390/catal15070684 - 15 Jul 2025

Viewed by 407

Abstract

In recent years, there has been unprecedented emphasis on the development of renewable and sustainable energy sources to produce clean and environmentally friendly energy [...] Full article

(This article belongs to the Special Issue Recent Advances in Energy-Related Materials in Catalysts, 2nd Edition)

12 pages, 2721 KiB

Open AccessFeature PaperArticle

Conjugated Polyaniline–Phytic Acid Polymer Derived 3D N, P-Doped Porous Carbon as a Metal-Free Electrocatalyst for Zn–Air Batteries

by Wanting Xiong, Yifan Kong, Jiangrong Xiao, Tingting Wang and Xiaoli Chen

Catalysts 2025, 15(7), 683; https://doi.org/10.3390/catal15070683 - 14 Jul 2025

Viewed by 423

Abstract

The development of cost-effective and scalable air/oxygen electrode materials is crucial for the advancement of Zn–air batteries (ZABs). Porous carbon materials doped with heteroatoms have attracted considerable attention in energy and environmental fields because of their tunable nanoporosity and high electrical conductivity. In [...] Read more.

The development of cost-effective and scalable air/oxygen electrode materials is crucial for the advancement of Zn–air batteries (ZABs). Porous carbon materials doped with heteroatoms have attracted considerable attention in energy and environmental fields because of their tunable nanoporosity and high electrical conductivity. In this work, we report the synthesis of a three-dimensional (3D) N and P co-doped porous carbon (PA@pDC-1000), derived from a conjugated polyaniline–phytic acid polymer. The cross-linked, rigid conjugated polymeric framework plays a crucial role in maintaining the integrity of micro- and mesoporous structures and promoting graphitization during carbonization. As a result, the material exhibits a hierarchical pore structure, a high specific surface area (1045 m² g⁻¹), and a large pore volume (1.02 cm³ g⁻¹). The 3D N, P co-doped PA@pDC-1000 catalyst delivers a half-wave potential of 0.80 V (vs. RHE) and demonstrates a higher current density compared to commercial Pt/C. A primary ZAB utilizing this material achieves an open-circuit voltage of 1.51 V and a peak power density of 217 mW cm⁻². This metal-free, self-templating presents a scalable route for the generating and producing of high-performance oxygen reduction reaction catalysts for ZABs. Full article

(This article belongs to the Special Issue Electrocatalysis and Photocatalysis in Redox Flow Batteries)

► Show Figures

Figure 1

17 pages, 1170 KiB

Open AccessArticle

Effect of Sulfur Poisoning During Worldwide Harmonized Light Vehicles Test Cycle on NOx Reduction Performance and Active Sites of Selective Catalytic Reduction Filter

by Zhou Zhou, Fei Yu, Dongxia Yang, Shiying Chang, Xiaokun He, Yunkun Zhao, Jiangli Ma, Ting Chen, Huilong Lai and He Lin

Catalysts 2025, 15(7), 682; https://doi.org/10.3390/catal15070682 - 14 Jul 2025

Viewed by 458

Abstract

Selective catalytic reduction filter (SDPF) technology constitutes a critical methodology for controlling nitrogen oxide (NOx) and particulate matter emissions from light-duty diesel vehicles. A series of SDPFs with different sulfur poisoning times and concentrations were prepared using the worldwide harmonized light [...] Read more.

Selective catalytic reduction filter (SDPF) technology constitutes a critical methodology for controlling nitrogen oxide (NOx) and particulate matter emissions from light-duty diesel vehicles. A series of SDPFs with different sulfur poisoning times and concentrations were prepared using the worldwide harmonized light vehicles test cycle (WLTC). Bench testing revealed that sulfur poisoning diminished the catalyst’s NH₃ storage capacity, impaired the transient NOx reduction efficiency, and induced premature ammonia leakage. After multiple sulfur poisoning incidents, the NOx reduction performance stabilized. Higher SO₂ concentrations accelerated catalyst deactivation and hastened the attainment of this equilibrium state. The characterization results for the catalyst indicate that the catalyst accumulated the same sulfur content after tail gas poisoning with different sulfur concentrations and that sulfur existed in the form of SO₄²⁻. The sulfur species in low-sulfur-poisoning-concentration catalysts mainly included sulfur ammonia and sulfur copper species, while high-sulfur-poisoning-concentration catalysts contained a higher proportion of sulfur copper species. Neither species type significantly altered the zeolite coating’s crystalline structure. Sulfur ammonia species could easily lead to a significant decrease in the specific surface area of the catalyst, which could be decomposed at 500 °C to achieve NOx reduction performance regeneration. In contrast, sulfur copper species required higher decomposition temperatures (600 °C), achieving only partial regeneration. Full article

(This article belongs to the Section Environmental Catalysis)

► Show Figures

Graphical abstract

14 pages, 3218 KiB

Open AccessArticle

Multi-Task Regression Model for Predicting Photocatalytic Performance of Inorganic Materials

by Zai Chen, Wen-Jie Hu, Hua-Kai Xu, Xiang-Fu Xu and Xing-Yuan Chen

Catalysts 2025, 15(7), 681; https://doi.org/10.3390/catal15070681 - 14 Jul 2025

Viewed by 458

Abstract

As renewable energy technologies advance, identifying efficient photocatalytic materials for water splitting to produce hydrogen has become an important research focus in materials science. This study presents a multi-task regression model (MTRM) designed to predict the conduction band minimum (CBM), valence band maximum [...] Read more.

As renewable energy technologies advance, identifying efficient photocatalytic materials for water splitting to produce hydrogen has become an important research focus in materials science. This study presents a multi-task regression model (MTRM) designed to predict the conduction band minimum (CBM), valence band maximum (VBM), and solar-to-hydrogen efficiency (STH) of inorganic materials. Utilizing crystallographic and band gap data from over 15,000 materials in the SNUMAT database, machine-learning methods are applied to predict CBM and VBM, which are subsequently used as additional features to estimate STH. A deep neural network framework with a multi-branch, multi-task regression structure is employed to address the issue of error propagation in traditional cascading models by enabling feature sharing and joint optimization of the tasks. The calculated results show that, while traditional tree-based models perform well in single-task predictions, MTRM achieves superior performance in the multi-task setting, particularly for STH prediction, with an MSE of 0.0001 and an R² of 0.8265, significantly outperforming cascading approaches. This research provides a new approach to predicting photocatalytic material performance and demonstrates the potential of multi-task learning in materials science. Full article

(This article belongs to the Special Issue Recent Developments in Photocatalytic Hydrogen Production)

► Show Figures

Figure 1

16 pages, 3763 KiB

Open AccessFeature PaperArticle

Enhanced Sulfamethazine Degradation over a Wide pH Range by Cost-Effective Zero-Valent Iron-Based Electro-Fenton/Sulfite Process

by Jiayi He, Ge Song, Akhtar Islam and Minghua Zhou

Catalysts 2025, 15(7), 680; https://doi.org/10.3390/catal15070680 - 12 Jul 2025

Viewed by 488

Abstract

Sulfamethazine (SMT) is an antibiotic with good antimicrobial effect and is widely used to treat human and livestock diseases. Though the degradation of SMT by the conventional Fenton and electro-Fenton (EF) processes is efficient, it is limited by a narrow pH and iron [...] Read more.

Sulfamethazine (SMT) is an antibiotic with good antimicrobial effect and is widely used to treat human and livestock diseases. Though the degradation of SMT by the conventional Fenton and electro-Fenton (EF) processes is efficient, it is limited by a narrow pH and iron sludge generation. Herein, we constructed a cost-effective EF system with the synergistic effect of zero-valent iron (Fe⁰) and sulfite (Fe⁰-EF/Sulfite), and key parameters such as applied current, catalyst dosing, sulfite dosage, and initial pH were optimized. Under the optimal conditions (Fe⁰ dosing of 50 mg/L, sulfite dosage of 1.5 mM, current of 40 mA, and pH of 3), the removal efficiency of 10 mg/L SMT reached 100% within 30 min, and the degradation rate constant reached 0.194 min⁻¹. Electron paramagnetic resonance (EPR) analysis and quenching experiments confirmed the generation of various reactive oxygen species (ROS), such as ^•OH, SO₄⁻, O₂⁻, and ¹O₂, which significantly improved the pollutant removal efficiency. Sulfite accelerated iron cycling and inhibited the formation of iron sludge, thus broadening the pH range of the reaction from three to eight and overcoming the limitations of the conventional EF process. The Fe⁰-EF/Sulfite system performs cost-effectively at a wide pH range, providing an efficient and low-carbon solution for environmental pollution remediation with broad application prospects. Full article

(This article belongs to the Special Issue Catalytic Materials for Hazardous Wastewater Treatment)

► Show Figures

Graphical abstract

18 pages, 1698 KiB

Open AccessReview

Enantioselective Iodination and Bromination for the Atroposelective Construction of Axially Chiral Compounds

by Xilong Wang, Shunwei Zhao, Yao Zhang, Dongya Bai, Fengbo Qu, Zhiyi Song, Hui Chen and Tingting Liu

Catalysts 2025, 15(7), 679; https://doi.org/10.3390/catal15070679 - 12 Jul 2025

Viewed by 698

Abstract

Axially chiral compounds play a pivotal role in organic synthesis, materials science, and pharmaceutical development. Among the various strategies for their construction, enantioselective iodination and bromination have emerged as powerful and versatile approaches, enabling the introduction of halogen functionalities that serve as valuable [...] Read more.

Axially chiral compounds play a pivotal role in organic synthesis, materials science, and pharmaceutical development. Among the various strategies for their construction, enantioselective iodination and bromination have emerged as powerful and versatile approaches, enabling the introduction of halogen functionalities that serve as valuable synthetic handles for further transformations. This review highlights recent advances in atroposelective iodination and bromination, with a particular focus on the synthesis of axially chiral biaryl and heterobiaryl frameworks. Key catalytic systems are discussed, including transition metal complexes, small-molecule organocatalysts, and high-valent metal catalysts in combination with chiral ligands or transient directing groups. Representative case studies are presented to elucidate mechanistic pathways, stereochemical induction models, and synthetic applications. Despite notable progress, challenges remain, such as expanding substrate scope, improving atom economy, and achieving high levels of regio- and stereocontrol in complex molecular settings. This review aims to provide a comprehensive overview of these halogenation strategies and offers insights to guide future research in the atroposelective synthesis of axially chiral molecules. Full article

(This article belongs to the Special Issue Asymmetric Catalysis: Recent Progress and Future Perspective)

► Show Figures

Scheme 1

24 pages, 1332 KiB

Open AccessFeature PaperReview

Strategies for the Removal of Per- and Polyfluoroalkyl Substances: A Review

by Feng Wang, Mingtong Wang, Ling Xu, Jingya Qian, Bin Zou, Shuhao Huo, Guoqiang Guan and Kai Cui

Catalysts 2025, 15(7), 678; https://doi.org/10.3390/catal15070678 - 12 Jul 2025

Viewed by 878

Abstract

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of synthetic fluorine-containing organic compounds that exhibit chemical and thermal stability due to the highly stable carbon–fluorine bonds present in their molecular structures. This characteristic makes them slow to degrade in the natural environment. With [...] Read more.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of synthetic fluorine-containing organic compounds that exhibit chemical and thermal stability due to the highly stable carbon–fluorine bonds present in their molecular structures. This characteristic makes them slow to degrade in the natural environment. With the widespread application of these compounds in the industrial and consumer goods sectors, environmental media such as water, air, soil, and food have been severely polluted, posing a range of significant threats to public health. Therefore, the development of efficient, economical, and environmentally friendly PFAS removal technologies has become a current research hotspot. This review systematically summarizes the current technologies for removing PFASs from four perspectives—physical, chemical, biological, and combined treatments—enabling a clear understanding of the existing treatment strategies to be discussed. In addition, suggestions for future research on PFAS removal are provided. Full article

► Show Figures

Graphical abstract

20 pages, 2590 KiB

Open AccessArticle

Application of Fused Filament Fabrication in Preparation of Ceramic Monolithic Catalysts for Oxidation of Gaseous Mixture of Volatile Aromatic Compounds

by Filip Car, Dominik Horvatić, Vesna Tomašić, Domagoj Vrsaljko and Zoran Gomzi

Catalysts 2025, 15(7), 677; https://doi.org/10.3390/catal15070677 - 11 Jul 2025

Viewed by 425

Abstract

The aim of this work was the preparation of ceramic monolithic catalysts for the catalytic oxidation of gaseous mixture of benzene, toluene, ethylbenzene and o-xylene BTEX. The possibility of using zirconium dioxide (ZrO₂) as a filament for the fabrication of 3D-printed [...] Read more.

The aim of this work was the preparation of ceramic monolithic catalysts for the catalytic oxidation of gaseous mixture of benzene, toluene, ethylbenzene and o-xylene BTEX. The possibility of using zirconium dioxide (ZrO₂) as a filament for the fabrication of 3D-printed ceramic monolithic carriers was investigated using fused filament fabrication. A mixed manganese and iron oxide, MnFeO_x, was used as the catalytically active layer, which was applied to the monolithic substrate by wet impregnation. The approximate geometric surface area of the obtained carrier was determined to be 53.4 cm², while the mass of the applied catalytically active layer was 50.3 mg. The activity of the prepared monolithic catalysts for the oxidation of BTEX was tested at different temperatures and space times. The results obtained were compared with those obtained with commercial monolithic catalysts made of ceramic cordierite with different channel dimensions, and with monolithic catalysts prepared by stereolithography. In the last part of the work, a kinetic analysis and the modeling of the monolithic reactor were carried out, comparing the experimental results with the theoretical results obtained with the 1D pseudo-homogeneous and 1D heterogeneous models. Although both models could describe the investigated experimental system very well, the 1D heterogeneous model is preferable, as it takes into account the heterogeneity of the reaction system and therefore provides a more realistic description. Full article

(This article belongs to the Section Catalytic Reaction Engineering)

► Show Figures

Figure 1

18 pages, 2242 KiB

Open AccessArticle

Regulation of Ag₁Cu_x/SBA-15 Catalyst for Efficient CO Catalytic Degradation at Room Temperature

by Fukun Bi, Haotian Hu, Ye Zheng, Yanxuan Wang, Yuxin Wang, Baolin Liu, Han Dong and Xiaodong Zhang

Catalysts 2025, 15(7), 676; https://doi.org/10.3390/catal15070676 - 11 Jul 2025

Viewed by 422

Abstract

The regulation of the active sites of a catalyst is important for its application. Herein, a series of Ag₁Cu_x/SBA-15 catalysts with different molar ratios of Ag to Cu were synthesized via the impregnation method, and the active sites of [...] Read more.

The regulation of the active sites of a catalyst is important for its application. Herein, a series of Ag₁Cu_x/SBA-15 catalysts with different molar ratios of Ag to Cu were synthesized via the impregnation method, and the active sites of Ag₁Cu_x were regulated via various pretreatment conditions. These as-prepared Ag₁Cu_x/SBA-15 catalysts were characterized by many technologies, and their catalytic performance was estimated through CO catalytic oxidation. Among these catalysts, Ag₁Cu_0.025/SBA-15, with a Ag/Cu molar ratio of 1:0.025 and pretreated under the condition of 500 °C O₂/Ar for 2 h, followed by 300 °C H₂ for another 2 h, presented optimal CO degradation performance, which could realize the oxidation of 98% CO at 34 °C (T₉₈ = 34 °C). Meanwhile, Ag₁Cu_0.025/SBA-15 also displayed great reusability. Characterization results, such as X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectra (UV-vis DRS), temperature-programmed H₂ reduction (H₂-TPR), and physical adsorption, suggested that the optimal catalytic performance of Ag₁Cu_0.025/SBA-15 was ascribed to its high interspersion of Ag nanoparticles, better low-temperature reduction ability, the interaction between Ag and Cu, and its high surface area and large pore volume. This study provides guidance for the regulation of active sites for low-temperature catalytic degradation. Full article

(This article belongs to the Special Issue Zeolites as Catalysts: Applications in Chemical Engineering, Energy Sources and Environmental Protection, 2nd Edition)

► Show Figures

Figure 1

29 pages, 3791 KiB

Open AccessArticle

Production of Sustainable Synthetic Natural Gas from Carbon Dioxide and Renewable Energy Catalyzed by Carbon-Nanotube-Supported Ni and ZrO₂ Nanoparticles

by João Pedro Bueno de Oliveira, Mariana Tiemi Iwasaki, Henrique Carvalhais Milanezi, João Lucas Marques Barros, Arnaldo Agostinho Simionato, Bruno da Silva Marques, Carlos Alberto Franchini, Ernesto Antonio Urquieta-González, Ricardo José Chimentão, José Maria Corrêa Bueno, Adriana Maria da Silva and João Batista Oliveira dos Santos

Catalysts 2025, 15(7), 675; https://doi.org/10.3390/catal15070675 - 11 Jul 2025

Viewed by 518

Abstract

The production of synthetic natural gas in the context of power-to-gas is a promising technology for the utilization of CO₂. Ni-based catalysts supported on carbon nanotubes (CNTs) were prepared through incipient wetness impregnation and characterized using N₂ adsorption, X-ray diffraction [...] Read more.

The production of synthetic natural gas in the context of power-to-gas is a promising technology for the utilization of CO₂. Ni-based catalysts supported on carbon nanotubes (CNTs) were prepared through incipient wetness impregnation and characterized using N₂ adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and temperature-programmed reduction (TPR). The catalysts were tested for CO₂ methanation in the 200–400 °C temperature range and at atmospheric pressure. The results demonstrated that the catalytic activity increased with the addition of the CNTs and Ni loading. The selectivity towards CH₄ was close to 100% for the Ni/ZrO₂/CNT catalysts. Reduction of the calcined catalyst at 500 °C using H₂ modified the surface chemistry of the catalyst, leading to an increase in the Ni particles. The CO₂ conversion was dependent on the Ni loading and the temperature reduction in the NiO species. The 10Ni/ZrO₂/CNT catalyst was highly stable in CO₂ methanation at 350 °C for 24 h. Thus, CNTs combined with Ni and ZrO₂ were considered promising for use as catalysts in CO₂ methanation at low temperatures. Full article

(This article belongs to the Special Issue Sustainable Catalytic Routes for the Production of Green Synthetic Fuels and Other Value-Added Products)

► Show Figures

Graphical abstract

20 pages, 4894 KiB

Open AccessArticle

Ag-Cu Synergism-Driven Oxygen Structure Modulation Promotes Low-Temperature NO_x and CO Abatement

by Ruoxin Li, Jiuhong Wei, Bin Jia, Jun Liu, Xiaoqing Liu, Ying Wang, Yuqiong Zhao, Guoqiang Li and Guojie Zhang

Catalysts 2025, 15(7), 674; https://doi.org/10.3390/catal15070674 - 11 Jul 2025

Viewed by 394

Abstract

The efficient simultaneous removal of NO_x and CO from sintering flue gas under low-temperature conditions (110–180 °C) in iron and steel enterprises remains a significant challenge in the field of environmental catalysis. In this study, we present an innovative strategy to enhance [...] Read more.

The efficient simultaneous removal of NO_x and CO from sintering flue gas under low-temperature conditions (110–180 °C) in iron and steel enterprises remains a significant challenge in the field of environmental catalysis. In this study, we present an innovative strategy to enhance the performance of CuSmTi catalysts through silver modification, yielding a bifunctional system capable of oxygen structure regulation and demonstrating superior activity for the combined NH₃-SCR and CO oxidation reactions under low-temperature, oxygen-rich conditions. The modified AgCuSmTi catalyst achieves complete NO conversion at 150 °C, representing a 50 °C reduction compared to the unmodified CuSmTi catalyst (T_100% = 200 °C). Moreover, the catalyst exhibits over 90% N₂ selectivity across a broad temperature range of 150–300 °C, while achieving full CO oxidation at 175 °C. A series of characterization techniques, including XRD, Raman spectroscopy, N₂ adsorption, XPS, and O₂-TPD, were employed to elucidate the Ag-Cu interaction. These modifications effectively optimize the surface physical structure, modulate the distribution of acid sites, increase the proportion of Lewis acid sites, and enhance the activity of lattice oxygen species. As a result, they effectively promote the adsorption and activation of reactants, as well as electron transfer between active species, thereby significantly enhancing the low-temperature performance of the catalyst. Furthermore, in situ DRIFTS investigations reveal the reaction mechanisms involved in NH₃-SCR and CO oxidation over the Ag-modified CuSmTi catalyst. The NH₃-SCR process predominantly follows the L-H mechanism, with partial contribution from the E-R mechanism, whereas CO oxidation proceeds via the MvK mechanism. This work demonstrates that Ag modification is an effective approach for enhancing the low-temperature performance of CuSmTi-based catalysts, offering a promising technical solution for the simultaneous control of NO_x and CO emissions in industrial flue gases. Full article

(This article belongs to the Special Issue Environmentally Friendly Catalysis for Green Future)

► Show Figures

Graphical abstract

25 pages, 6054 KiB

Open AccessReview

Recent Advances in Biocatalytic Dearomative Spirocyclization Reactions

by Xiaorui Chen, Changtong Zhu, Luyun Ji, Changmei Liu, Yan Zhang, Yijian Rao and Zhenbo Yuan

Catalysts 2025, 15(7), 673; https://doi.org/10.3390/catal15070673 - 10 Jul 2025

Viewed by 716

Abstract

Spirocyclic architectures, which feature two rings sharing a single atom, are common in natural products and exhibit beneficial biological and material properties. Due to the significance of these architectures, biocatalytic dearomative spirocyclization has recently emerged as a powerful approach for constructing three-dimensional spirocyclic [...] Read more.

Spirocyclic architectures, which feature two rings sharing a single atom, are common in natural products and exhibit beneficial biological and material properties. Due to the significance of these architectures, biocatalytic dearomative spirocyclization has recently emerged as a powerful approach for constructing three-dimensional spirocyclic frameworks under mild, sustainable conditions and with exquisite stereocontrol. This review surveys the latest advances in biocatalyzed spirocyclization of all-carbon arenes (phenols and benzenes), aza-aromatics (indoles and pyrroles), and oxa-aromatics (furans). We highlight cytochrome P450s, flavin-dependent monooxygenases, multicopper oxidases, and novel metalloenzyme platforms that effect regio- and stereoselective oxidative coupling, epoxidation/semi-pinacol rearrangement, and radical-mediated cyclization to produce diverse spirocycles. Mechanistic insights gleaned from structural, computational, and isotope-labeling studies are discussed where necessary to help the readers further understand the reported reactions. Collectively, these examples demonstrate the transformative potential of biocatalysis to streamline access to spirocyclic scaffolds that are challenging to prepare through traditional methods, underscoring biocatalysis as a transformative tool for synthesizing pharmaceutically relevant spiroscaffolds while adhering to green chemistry paradigms to ultimately contribute to a cleaner and more sustainable future. Full article

(This article belongs to the Section Biocatalysis)

► Show Figures

Graphical abstract

18 pages, 4550 KiB

Open AccessArticle

Efficient Visible-Light-Driven Photocatalysis of BiVO₄@Diatomite for Degradation of Methoxychlor

by Nazar Iqbal, Xiaocui Huang, Khalid Mohamedali Hamid, Hongming Yuan, Irum Batool and Yuxiang Yang

Catalysts 2025, 15(7), 672; https://doi.org/10.3390/catal15070672 - 10 Jul 2025

Viewed by 526

Abstract

As a persistent organic pollutant, methoxychlor has drawn considerable environmental attention. Photocatalysis, recognized for its environmentally friendly characteristics, has been widely utilized for the degradation of contaminants. In this study, the photocatalytic material BiVO₄@diatomite was successfully synthesized via the liquid-phase precipitation [...] Read more.

As a persistent organic pollutant, methoxychlor has drawn considerable environmental attention. Photocatalysis, recognized for its environmentally friendly characteristics, has been widely utilized for the degradation of contaminants. In this study, the photocatalytic material BiVO₄@diatomite was successfully synthesized via the liquid-phase precipitation method. The synthesized material was comprehensively characterized using X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy (DRS), and a Brunauer–Emmett–Teller (BET) analysis, providing robust evidence for the material’s stability and biocompatibility. The results confirmed the successful deposition of BiVO₄ onto the diatomite surface. Furthermore, the effects of various parameters, including the initial methoxychlor concentration, pH, light exposure duration, and illumination intensity, on the photocatalytic degradation efficiency of methoxychlor by BiVO₄@diatomite were systematically investigated to optimize degradation performance. The identification of optimal reaction conditions and the proposed degradation mechanism based on experimental findings will be valuable for guiding future studies and practical applications in environmental pollution control. The integration of BiVO₄ with diatomite in this study yields a novel composite system with significantly enhanced photocatalytic degradation performance, offering fresh insights into the design of efficient, stable, and eco-friendly materials for pollutant removal. Full article

(This article belongs to the Special Issue Advanced Oxidation Catalysis and Sustainable Technologies for Water Purification)

► Show Figures

Figure 1

22 pages, 6102 KiB

Open AccessFeature PaperReview

Current Developments in Ozone Catalyst Preparation Techniques and Their Catalytic Oxidation Performance

by Jiajia Gao, Siqi Chen, Yun Gao, Wenquan Sun, Jun Zhou, Kinjal J. Shah and Yongjun Sun

Catalysts 2025, 15(7), 671; https://doi.org/10.3390/catal15070671 - 10 Jul 2025

Viewed by 433

Abstract

Through the use of heterogeneous catalysts, catalytic ozone oxidation technology, an effective and eco-friendly advanced oxidation process (AOP), facilitates the breakdown of ozone into reactive oxygen species (like ·OH) and greatly increases the mineralization efficiency of pollutants. This study examines the development of [...] Read more.

Through the use of heterogeneous catalysts, catalytic ozone oxidation technology, an effective and eco-friendly advanced oxidation process (AOP), facilitates the breakdown of ozone into reactive oxygen species (like ·OH) and greatly increases the mineralization efficiency of pollutants. This study examines the development of heterogeneous ozone catalysts through a critical evaluation of the five primary preparation techniques: ion exchange, sol–gel, coprecipitation, impregnation, and hydrothermal synthesis. Each preparation method’s inherent qualities, benefits, drawbacks, and performance variations are methodically investigated, with an emphasis on how they affect the breakdown of different resistant organic compounds. Even though heterogeneous catalysts are more stable and reusable than homogeneous catalysts, they continue to face issues like active component leaching, restricted mass transfer, and ambiguous mechanisms. In order to determine the key paths for catalyst selection in catalytic ozone treatment going forward, the main goal of this review is to provide an overview of the accomplishments in the field of the heterogeneous ozone catalyst treatment of wastewater that is difficult to degrade. Full article

(This article belongs to the Special Issue Environmentally Friendly Catalysis for Green Future)

► Show Figures

Figure 1

22 pages, 8848 KiB

Open AccessFeature PaperReview

Sustainable Treatment of Plastic Wastes with Photocatalytic Technologies: A Review

by Xin Wang, Xiaoling Ye, Duqiang Zhang, Bingxu Zhang, Huimei Liu and Wenbin Qu

Catalysts 2025, 15(7), 670; https://doi.org/10.3390/catal15070670 - 10 Jul 2025

Viewed by 669

Abstract

Plastic waste pollution has been widely recognized as one of the most severe and pressing environmental challenges of our time, posing significant threats to ecosystem stability and human health. The transformation of plastic waste into high-value chemicals and clean energy via photocatalytic reforming [...] Read more.

Plastic waste pollution has been widely recognized as one of the most severe and pressing environmental challenges of our time, posing significant threats to ecosystem stability and human health. The transformation of plastic waste into high-value chemicals and clean energy via photocatalytic reforming technology is increasingly regarded as a promising and sustainable alternative pathway, offering dual benefits of resource recovery and environmental remediation. This review first provides an overview of the current state of research on plastic waste management. It then systematically summarizes recent representative advances in the coupling of plastic upcycling with photocatalytic technologies, with a particular focus on the potential of plastics as carbon sources in both photodegradation and photosynthetic transformation pathways, highlighting their value and future prospects. Finally, this review outlines the key scientific challenges that urgently need to be addressed in the field of photocatalytic conversion of plastic waste, and, in light of emerging research trends, proposes several promising directions for future investigation along with the authors’ perspectives. It is hoped that these insights will provide useful guidance and inspiration for the continued advancement of this field. Full article

(This article belongs to the Special Issue Advances in Catalytic Processes for Carbon Neutralization)

► Show Figures

Graphical abstract

21 pages, 3111 KiB

Open AccessArticle

Iron Sludge-Derived Photo-Fenton Reaction for Laundry Wastewater Effluent Oxidation and Process Optimization into Industrial Ecology Symbiosis

by Amira Ben Gouider Trabelsi, Fatemah H. Alkallas, Shehab A. Mansour, Abdullah F. Al Naim, Adil Alshoaibi, Najeh Rekik, Manasik M. Nour and Maha A. Tony

Catalysts 2025, 15(7), 669; https://doi.org/10.3390/catal15070669 - 10 Jul 2025

Viewed by 475

Abstract

Controlled iron extraction from iron-based sludge (Fe-Sludge) drainage and its use as a Fenton’s reagent is investigated in the current study for eliminating organics from launderette discharge stream. The influences of the iron dosage, hydrogen peroxide concentration, and pH are assessed [...] Read more.

Controlled iron extraction from iron-based sludge (Fe-Sludge) drainage and its use as a Fenton’s reagent is investigated in the current study for eliminating organics from launderette discharge stream. The influences of the iron dosage, hydrogen peroxide concentration, and pH are assessed as treatment factors for their direct impact on the oxidation of organic compounds. Additionally, optimal oxidation conditions are determined using the response surface methodology (RSM) technique, and the ranges of treatment variables are analyzed. The optimum values of a pH of 2.0, Fe sludge concentration of 99 mg/L, and H₂O₂ content of 402 mg/L resulted in optimal organics removal of up to 98%, expressed as Chemical Oxygen Demand (COD) removal. The oxidation efficacy attained from the design is confirmed and the model validation is assessed, and the suggestive model is accepted since it possesses a correlation coefficient of 97.7%. The thermodynamic and kinetic models are also investigated, and the reaction showed that the temperature increases resulted in the oxidation efficiency being reduced. The oxidation efficiency expressed as COD reduction is clearly characterized by first-order reaction kinetics. The thermodynamic characteristics indicated that the oxidation reaction was exothermic and not spontaneous. Full article

(This article belongs to the Special Issue Advanced Catalytic Processes for Wastewater Treatment)

► Show Figures

Graphical abstract

31 pages, 8391 KiB

Open AccessFeature PaperReview

Recent Advances in Catalyst Innovation, Mechanism Exploration, and Process Optimization for Synthesis of Glycerol Carbonate

by Honglei Sun, Zhenyu Lei, Jinghui Shi and Mingjun Jia

Catalysts 2025, 15(7), 668; https://doi.org/10.3390/catal15070668 - 9 Jul 2025

Viewed by 672

Abstract

The catalytic conversion of bio-based glycerol (Gly) into high-value glycerol carbonate (GC) has received great attention from both the academic and industrial fields. The development of highly efficient catalysts and economical industrial processes remains a challenging subject. In this mini-review, we summary the [...] Read more.

The catalytic conversion of bio-based glycerol (Gly) into high-value glycerol carbonate (GC) has received great attention from both the academic and industrial fields. The development of highly efficient catalysts and economical industrial processes remains a challenging subject. In this mini-review, we summary the recent advances in catalyst design, characterization, mechanism, and catalytic process optimization, including the various synthetic strategies of GC, such as the coupling of CO₂ and Gly or its derivatives like glycidol (GD), the transesterification of Gly with small carbonate-containing molecules, and the carbonylation of Gly with urea. The main difficulties and challenges faced by constructing high-performance catalysts and achieving scale production of GC have been put forward, and the future research directions and opportunities in catalyst innovation, reaction mechanism exploration, and continuous catalytic process improvement have also been suggested. Full article

(This article belongs to the Special Issue Heterogeneous Catalysis for Biomass and Its Derivatives into Chemicals)

► Show Figures

Graphical abstract

14 pages, 935 KiB

Open AccessArticle

Plasmon-Driven Catalytic Inhibition of pATP Oxidation as a Mechanism for Indirect Fe²⁺ Detection on a SERS-Active Platform

by Alexandru-Milentie Hada, Mihail-Mihnea Moruz, Alexandru Holca, Simion Astilean, Marc Lamy de la Chapelle and Monica Focsan

Catalysts 2025, 15(7), 667; https://doi.org/10.3390/catal15070667 - 8 Jul 2025

Viewed by 555

Abstract

The detection of Fe²⁺ in environmental water sources is critical due to its biological relevance and potential toxicity at elevated levels. Herein, we report a plasmon-driven catalytic sensing nanoplatform based on p-aminothiophenol (pATP)-functionalized silver nanoparticles (AgNPs) for the selective and sensitive detection [...] Read more.

The detection of Fe²⁺ in environmental water sources is critical due to its biological relevance and potential toxicity at elevated levels. Herein, we report a plasmon-driven catalytic sensing nanoplatform based on p-aminothiophenol (pATP)-functionalized silver nanoparticles (AgNPs) for the selective and sensitive detection of Fe²⁺. The nanoplatform exploits the inhibition of the plasmon-driven catalytic conversion of pATP to 4,4-dimercaptoazobenzene (DMAB), monitored via surface-enhanced Raman scattering (SERS) spectroscopy. The catalytic efficiency was quantified by the intensity ratio between the formed DMAB-specific Raman band and the common aromatic ring vibration band of pATP and DMAB. This ratio decreased proportionally with increasing Fe²⁺ concentration over a range of 100 µM to 1.5 mM, with a calculated limit of detection of 39.7 µM. High selectivity was demonstrated against common metal ions, and excellent recovery rates (96.6–99.4%) were obtained in real water samples. Mechanistic insights, supported by chronopotentiometric measurements under light irradiation, revealed a competitive oxidation pathway in which Fe²⁺ preferentially consumes plasmon-generated hot holes over pATP. This mechanism clarifies the observed catalytic inhibition and supports the design of redox-responsive SERS sensors. The platform offers a rapid, low-cost, and portable solution for Fe²⁺ monitoring and holds promise for broader applications in detecting other redox-active analytes in complex environmental matrices. Full article

(This article belongs to the Special Issue Innovative Catalytic and Photocatalytic Systems for Environmental Remediation, 2nd Edition)

► Show Figures

Figure 1

19 pages, 8425 KiB

Open AccessArticle

Efficiency of the Electrocatalytic Nitrate Reduction to Ammonia: Do the Surface Nanostructures Play an Essential Role?

by Olga Lebedeva, Irina Kuznetsova, Dmitry Kultin, Alexander Leonov, Maxim Zakharov, Alexander Kustov, Stanislav Dvoryak and Leonid Kustov

Catalysts 2025, 15(7), 666; https://doi.org/10.3390/catal15070666 - 8 Jul 2025

Viewed by 505

Abstract

The degradation of electrochemical materials during energy conversion and storage, in particular the electrocatalyst materials, is becoming increasingly important. The selection and design of sustainable materials is an important task. This work examines the synthesis, characterization, and application of an electrocatalyst (based on [...] Read more.

The degradation of electrochemical materials during energy conversion and storage, in particular the electrocatalyst materials, is becoming increasingly important. The selection and design of sustainable materials is an important task. This work examines the synthesis, characterization, and application of an electrocatalyst (based on an amorphous alloy Co75Si15Fe5Cr4.5) having a structured surface in the form of nanocells for a “green” nitrate reduction reaction (NO₃RR), which can serve as an alternative to the well-known Haber-Bosch process for the synthesis of ammonia. The material for the electrocatalyst was obtained by anodizing the alloy in the ionic liquid BmimNTf₂ and characterized by using a combination of modern physicochemical and electrochemical methods. The Faradaic efficiency (FE) for the nanocell catalyst exceeds by more than three-fold and seven-fold catalyst with a polished surface and the initial catalyst having a natural oxide on the surface, respectively. A mechanism of this reaction on the studied electrocatalysts with structured and non-structured surfaces is proposed. It is mentioned that the nanocell electrocatalyst is an extremely stable material that passes all tests without visible changes. The authors consider their work as a starting point for the application of a nanostructured Co-electrocatalyst in NO₃RR. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Catalysts, Volume 15, Issue 7 (July 2025) – 90 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI