Catalysts

19 pages, 2564 KB

Open AccessArticle

Untangling the Role of Organosilane Functional Groups in the Aerosol-Assisted Hydrothermal Synthesis of Sn-Beta Zeolites

by Yankai Li, Xu Feng, Shuo Wang, He Huang and Qingrun Meng

Catalysts 2026, 16(5), 426; https://doi.org/10.3390/catal16050426 - 5 May 2026

Abstract

In this work, various types of organosilanes were introduced into Sn-Si oxide through a simple aerosol process to yield synthesis precursors. Then, a series of Sn-Beta zeolites were successfully synthesized using a hydrothermal method in the presence of fluoride. The influence of amine [...] Read more.

In this work, various types of organosilanes were introduced into Sn-Si oxide through a simple aerosol process to yield synthesis precursors. Then, a series of Sn-Beta zeolites were successfully synthesized using a hydrothermal method in the presence of fluoride. The influence of amine groups (A, 2A, and 3A), the length of branched chains present in the organosilanes, as well as the use of dipodal silanization agents (B2A) on the morphology, pore structure, acidic properties, coordination state, and content of Sn species in the obtained Sn-Beta zeolite samples was investigated. Compared to the organosilane-free Sn-Beta (crystal size: 1.3 μm; Si/Sn = 119; Lewis acid density: 77 μmol·g⁻¹), all monopodal organosilane-doped samples (Sn-Beta-A, -2A, and -3A) exhibited reduced crystal sizes (~0.9 μm) and increased specific surface areas (up to 502 m²·g⁻¹ for Sn-Beta-2A). UV–Vis spectroscopy showed that Sn-Beta-2A (containing two amine groups) achieved the highest optical bandgap (4.68 eV) and the strongest suppression of extra-framework SnO_x species (peak at ~269 nm), indicating the most isolated tetrahedral framework Sn⁴⁺ sites. This sample also delivered the highest Lewis acid density (225 μmol·g⁻¹) and the best catalytic performance in the Baeyer–Villiger oxidation of cyclohexanone (39% conversion, TON = 106) and 2-adamantanone (37% conversion, TON = 101). By contrast, the dipodal organosilane (B₂A) caused severe steric hindrance, yielding the lowest crystallinity (relative crystallinity 64%), Si/Sn ratio (158), Lewis acid density (38 μmol·g⁻¹), and catalytic activity, despite forming a nanoaggregate morphology with high mesoporosity (V meso = 0.20 cm³·g⁻¹). These quantitative results demonstrate that monopodal organosilanes with two amine groups optimally balance Sn incorporation and textural properties, whereas dipodal silanes hinder framework Sn entry. This study provides clear, numerically grounded guidelines for selecting organosilane functional groups to design high-performance Sn-Beta zeolites. Full article

(This article belongs to the Special Issue State of the Art and Future Challenges in Zeolite Catalysts)

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19 pages, 7530 KB

Open AccessFeature PaperArticle

Enhanced Catalytic Performance of Red Mud for Toluene Oxidation via Acid Pretreatment-Induced Structural Modification

by Wenjun Liang, Ruifang Li, Qianyu Tao, Yuxue Zhu, Running Kang and Hongping Fang

Catalysts 2026, 16(5), 425; https://doi.org/10.3390/catal16050425 - 4 May 2026

Abstract

Red mud (RM), a metal oxide-rich solid waste, was subjected to three different acid treatments to evaluate its catalytic performance in toluene oxidation. The acetic acid-modified red mud (HAC-RM) demonstrated excellent catalytic activity, achieving complete toluene conversion at 450 °C. XRD, XRF, N [...] Read more.

Red mud (RM), a metal oxide-rich solid waste, was subjected to three different acid treatments to evaluate its catalytic performance in toluene oxidation. The acetic acid-modified red mud (HAC-RM) demonstrated excellent catalytic activity, achieving complete toluene conversion at 450 °C. XRD, XRF, N₂-BET and SEM results show acetic acid treatment can effectively remove pore-blocking inert components such as Na₂O and CaO, thus increased the Fe₂O₃ content, and significantly enhanced both the specific surface area and pore size of the catalyst. Furthermore, this modification enhanced reducibility and generated additional oxygen vacancies, verified by H₂-TPR and O₂-TPD, thereby improving the overall catalytic performance. In contrast, oxalic acid treatment under ultraviolet irradiation led to the formation of calcium carbonate via reaction with Ca²⁺ ions in RM, which resulted in reduced catalytic activity. To further enhance performance, MnO₂ was loaded onto the modified HAC-RM via an impregnation method to develop a low-cost and highly active catalyst. Among the prepared samples, 20%MnO₂/HAC-RM exhibited the highest catalytic efficiency, achieving 100% toluene conversion at 300 °C. XPS, H₂-TPR, and O₂-TPD results indicate the synergistic interaction between Fe₂O₃ and MnO₂ facilitated electron transfer and enhanced surface oxygen mobility. Additionally, the catalytic oxidation mechanism of 20% MnO₂/HAC-RM was elucidated. A detailed reaction pathway for toluene degradation is proposed by in situ DRIFT, as follows: toluene → benzyl alcohol → benzaldehyde/benzoyl peroxide → benzoate → CO₂ and H₂O. These findings are expected to contribute to the development of efficient, sustainable, and cost-effective catalysts for volatile organic compound (VOC) abatement. Full article

(This article belongs to the Special Issue Heterogeneous Catalysis in China: New Horizons and Recent Advances)

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29 pages, 8883 KB

Open AccessFeature PaperArticle

Pathways of Geraniol Transformation over a Mironekuton Catalyst

by Sylwia Gajewska, Agnieszka Wróblewska, Piotr Miądlicki, Beata Michalkiewicz, Luis A. Gallego-Villada and Anna Fajdek-Bieda

Catalysts 2026, 16(5), 424; https://doi.org/10.3390/catal16050424 - 4 May 2026

Abstract

The subject of the presented work was the study of the pathways of geraniol transformation during its oxidation with molecular oxygen in the presence of a natural Japanese volcanic clay mineral—mironekuton—used as a green heterogeneous catalyst. Prior to the catalytic tests, a comprehensive [...] Read more.

The subject of the presented work was the study of the pathways of geraniol transformation during its oxidation with molecular oxygen in the presence of a natural Japanese volcanic clay mineral—mironekuton—used as a green heterogeneous catalyst. Prior to the catalytic tests, a comprehensive characterization of mironekuton was carried out using SEM, XRD, EDX, FTIR, and UV–Vis techniques. The catalytic experiments were aimed at establishing reaction conditions enabling effective geraniol conversion and controlling the distribution of valuable transformation products under solvent-free conditions. The influence of temperature (75–100 °C), catalyst content (0.5–5.0 wt%), and reaction time (15–360 min) was systematically investigated. The obtained results demonstrated that pristine mironekuton exhibits moderate activity and limited selectivity toward low-molecular-weight oxygenated derivatives of geraniol, such as 2,3-epoxygeraniol, 2,3-epoxycitral, and citral. Instead, dehydration, isomerization, and dimerization reactions play a significant role, leading to the formation of higher-molecular-weight products, particularly thunbergol and 6,11-dimethyldodeca-2,6,10-trien-1-ol. Sulfuric acid treatment of mironekuton results in a pronounced enhancement of catalytic activity and a substantial shift in product distribution. This effect is directly related to the increased surface acidity, which promotes dehydration–dimerization pathways over epoxidation, leading to thunbergol as the dominant product with high and reproducible selectivity, while epoxidation products are no longer detected. Kinetic modeling of the geraniol transformation process revealed that epoxidation steps are kinetically disfavored and that epoxide species act only as short-lived intermediates, whereas dehydration–dimerization pathways are kinetically preferred. Overall, the results indicate that acid-activated mironekuton functions as an efficient and environmentally benign heterogeneous catalyst, favoring selective thunbergol formation under mild, solvent-free conditions, using molecular oxygen as a green oxidant. Full article

(This article belongs to the Special Issue Catalysis Accelerating Energy and Environmental Sustainability)

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16 pages, 6213 KB

Open AccessFeature PaperArticle

Co⁰-Co^δ+ Active Pairs Tailored in Co-W-C Catalysts via Reduction–Carburization for Synthesizing Ethanol from CO₂ Hydrogenation Under the Promotion of DMF

by Min Luo, Wei Wu and Linfei Xiao

Catalysts 2026, 16(5), 423; https://doi.org/10.3390/catal16050423 - 3 May 2026

Abstract

Hydrogenation of CO₂ to ethanol is regarded as a promising approach for the resource utilization of CO₂. Ethanol can be synthesized via the acetate pathway over cobalt-based catalysts, in which the regulation of Co⁰-Co^δ+ is crucial to [...] Read more.

Hydrogenation of CO₂ to ethanol is regarded as a promising approach for the resource utilization of CO₂. Ethanol can be synthesized via the acetate pathway over cobalt-based catalysts, in which the regulation of Co⁰-Co^δ+ is crucial to increasing the space–time yield of ethanol. In this research, a series of Co-W-C catalysts was prepared via the reduction-carburization method and their catalytic performance was investigated for synthesizing ethanol from CO₂ hydrogenation. During the preparation of Co-W-C catalysts, the Co, Co₆W₆C and WC phases were generated by employing a precursor containing Co, W and citric acid. This process drove the formation of Co^δ+ species and the consequent generation of Co⁰-Co^δ+ active pairs. Under the cooperation of Co⁰-Co^δ+ and WC, ethanol was obtained with high selectivity and space–time yield from the CO₂ hydrogenation under the promotion of DMF. Over the Co-W-C-1 catalyst prepared by a Co/W molar ratio of 1:1 in the precursor, an ethanol space–time yield of 17.1 mmol·g⁻¹·h⁻¹ with an ethanol selectivity of 99.6% among organic products was obtained. Furthermore, key intermediate species formed during the reaction were identified by in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy, and a possible reaction pathway was also proposed. Full article

(This article belongs to the Special Issue Engineering of Nanostructured Catalytic Materials for Selective Hydrogenation Reactions)

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23 pages, 5920 KB

Open AccessArticle

Investigation of Synergistic Effects of Hydrogenation and Copper Decoration on the Electrocatalytic Application (HER) of TiO₂ Nanotube Array Electrodes

by Hamed Namdar-Asl, M. A. Mohtadi-Bonab, Sadegh Pour-Ali, Leila Fathyunes and Farzaneh Shiran-Jang

Catalysts 2026, 16(5), 422; https://doi.org/10.3390/catal16050422 - 3 May 2026

Abstract

In this study, TiO₂ nanotube (TNTs) array electrodes were fabricated by electrochemical anodization and subsequently modified through thermal annealing, hydrogenation heat treatment, and chemical decoration with copper species at various immersion times to enhance their electrochemical performance. The structural, morphological, semiconducting, and [...] Read more.

In this study, TiO₂ nanotube (TNTs) array electrodes were fabricated by electrochemical anodization and subsequently modified through thermal annealing, hydrogenation heat treatment, and chemical decoration with copper species at various immersion times to enhance their electrochemical performance. The structural, morphological, semiconducting, and electrochemical properties of the modified nanotubes were systematically examined. FE-SEM and EDS analyses confirmed the formation of well-aligned TNTs and the successful deposition of copper species, with the most uniform surface distribution achieved for the sample decorated for 45 min. Raman spectroscopy and XRD results revealed that the anatase phase of TiO₂ remained stable after hydrogenation and copper decoration, while minor peak shifts indicated defect evolution and lattice distortion. Electrochemical evaluations, including linear sweep voltammetry, Tafel polarization, electrochemical impedance spectroscopy, and Mott–Schottky analysis, demonstrated a substantial enhancement in electrocatalytic activity following copper decoration. Compared with annealed and hydrogenated electrodes, the decorated samples exhibited markedly lower overpotentials, reduced cathodic Tafel slopes, and decreased charge-transfer resistance. Mott–Schottky analysis confirmed n-type semiconducting behavior for all electrodes, showing that hydrogenation increased donor density, whereas subsequent copper decoration slightly reduced it due to the partial substitution of oxygen vacancies by copper oxide species. Among all samples, the electrode decorated for 45 min (AA′HD45) exhibited the optimal balance between donor density, charge-transfer properties, and electrochemical performance. These results highlight the effectiveness of combining hydrogenation with optimized copper decoration to improve charge transport and interfacial kinetics in TNT electrodes for electrochemical applications. Full article

(This article belongs to the Special Issue In-Depth Study of Electrochemical Reduction Catalysts and Promoters toward Green and Sustainable Processes)

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14 pages, 1905 KB

Open AccessFeature PaperArticle

Alcoholysis Products by a GH53 Fungal Galactanase

by Marco Zanon, Theo Tonne Hønning Lyholm, Yusuf Theibich, Sara Jonsdottir Glaser and Leila Lo Leggio

Catalysts 2026, 16(5), 421; https://doi.org/10.3390/catal16050421 - 3 May 2026

Abstract

In this study, the native activity of an arabinogalactan endo-β-1,4-galactanase from Aspergillus niger (AnGal) was evaluated under different reaction conditions, and in the presence of various acceptor molecules during the cleavage of the β-1,4-glycosidic linkage of a chromogenic compound and lupin galactan. A [...] Read more.

In this study, the native activity of an arabinogalactan endo-β-1,4-galactanase from Aspergillus niger (AnGal) was evaluated under different reaction conditions, and in the presence of various acceptor molecules during the cleavage of the β-1,4-glycosidic linkage of a chromogenic compound and lupin galactan. A combination of spectrophotometric assays, mass spectrometry and chromatography techniques provided insights into the reaction mechanism of the enzyme and its use in the synthesis of galactosides and galactooligosaccharide derivatives. In reactions containing 2-nitrophenol galactopyranoside, AnGal promoted transglycosylation, generating longer galactooligosaccharide derivatives of 2-nitrophenol that have not previously been reported for GH53 enzymes. Furthermore, new alcoholysis products have been detected when AnGal acted on lupin galactan in the presence of benzyl alcohol. To the best of our knowledge, we are first to report the synthesis of galactotriose and galactotetraose derivatives formed by endo-β-1,4-galactanase alcoholysis. This work showcases the potential of utilizing galactanases in the synthesis of valuable galactosides and galactooligosaccharides, under mild conditions from sustainable biomass sources. Potential beneficial applications may be found in several industrial fields such as in the preparation of prodrugs and prebiotics. Full article

(This article belongs to the Special Issue Advances in Enzyme Engineering and Application for Industrial Biocatalysis)

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18 pages, 5407 KB

Open AccessArticle

Activation of Peracetic Acid by Waste Tea Residue-Derived Biochar for Bisphenol A Elimination: Synergetic Adsorption and Non-Radical Oxidation

by Shijun Zhu, Xinchen Zhang, Shangming Shen, Yang Wang, Yongshu Hu, Hao Yang, Wenbin Liu, Xiaoyan Ma and Jing Deng

Catalysts 2026, 16(5), 420; https://doi.org/10.3390/catal16050420 - 3 May 2026

Abstract

Biochar (BC)-activated peracetic acid (PAA)-based advanced oxidation processes (AOPs) were increasingly considered as cost-efficient and eco-friendly water treatment technologies for the removal of organic pollutants. However, the specific role of intrinsic carbon, nitrogen species and structure properties played in activation mechanism is still [...] Read more.

Biochar (BC)-activated peracetic acid (PAA)-based advanced oxidation processes (AOPs) were increasingly considered as cost-efficient and eco-friendly water treatment technologies for the removal of organic pollutants. However, the specific role of intrinsic carbon, nitrogen species and structure properties played in activation mechanism is still vague. In this study, the waste tea residues-based biochar (WTBC) was prepared by thermal carbonization and applied to activate PAA for the degradation of bisphenol A (BPA). The product carbonized at 800 °C (WTBC800) possessed larger specific surface area (342.57 m²/g), more abundant porous structure and massive defects state (I_D/I_G = 3.53), and exhibited a superior activation performance with 83.7% BPA removal within 120 min. Adsorption and non-radical oxidation pathways [e.g., the mediated electron transfer process (ETP) and singlet oxygen (¹O₂) generation] were evidenced to play the dominant roles in the BPA degradation through the formation of metastable complex WTBC-PAA*. The graphitic carbon, functional nitrogen species, defects structure and persistent free radicals (PFRs) in WTBC were proposed to contribute to the activation of PAA. Overall, relatively higher dosages of WTBC (0–0.5 g/L) and PAA (0–1.5 mM) facilitated the BPA degradation. The solution pH and water matrix (e.g., Cl⁻, NO₃⁻, HCO₃⁻ and SO₄²⁻) presented a negligible effect on the BPA degradation in WTBC/PAA system. This study not only proposes a sustainable approach for organic pollutants removal in wastewater, but also promotes the resource re-utilization of agricultural waste. Full article

(This article belongs to the Special Issue Novel Advanced Oxidation Processes for Catalytic Degradation of Emerging Contaminants)

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17 pages, 13372 KB

Open AccessArticle

Modeling and Optimization of Cumene Synthesis Using Zeolite-Catalyzed Alkylation

by Mohamed Bechir Ben Hamida

Catalysts 2026, 16(5), 419; https://doi.org/10.3390/catal16050419 - 3 May 2026

Abstract

This study focuses on simulating and optimizing cumene (isopropylbenzene) production via the alkylation of benzene with propylene using a beta zeolite catalyst. Two process configurations were evaluated: a conventional setup without a transalkylation reactor and an enhanced configuration incorporating a transalkylation unit to [...] Read more.

This study focuses on simulating and optimizing cumene (isopropylbenzene) production via the alkylation of benzene with propylene using a beta zeolite catalyst. Two process configurations were evaluated: a conventional setup without a transalkylation reactor and an enhanced configuration incorporating a transalkylation unit to convert byproducts back into cumene. The process was modeled under steady-state conditions in Aspen HYSYS using plug flow reactors and the Peng–Robinson fluid package, with reaction kinetics derived from established literature on zeolite-catalyzed systems. Optimization studies examined the effects of reactor temperature, pressure, and the benzene-to-propylene molar ratio. Increasing the reactor temperature to 178 °C improved propylene conversion to 96.20%, while raising the pressure from 3540 kPa to 3600 kPa further enhanced it to 96.24%. By optimizing the benzene-to-propylene molar feed ratio to approximately 1.02:1 and increasing the fresh benzene feed to 138.5 kmol/h, cumene production reached 135.792 kmol/h while minimizing byproduct formation. Comparative analysis revealed that the configuration without a transalkylation reactor generated 4.171 kmol/h of diisopropylbenzene (DIPB) as waste, representing both economic loss and environmental concern due to its toxicity. In contrast, the integration of a transalkylation reactor enabled the conversion of DIPB into additional cumene, significantly improving process efficiency and sustainability. These findings demonstrate that optimizing reaction conditions and integrating a transalkylation step substantially enhances cumene yield and reduces waste, leading to a more viable and environmentally friendly industrial process. Full article

(This article belongs to the Special Issue Zeolites and Zeolite-Based Catalysis: Development, Application and Challenges)

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22 pages, 3644 KB

Open AccessArticle

RuO₂-CeO₂@Ti Anode for Electrocatalytic Degradation of Acid Orange 3: Performance Evaluation and Mechanistic Study

by Ai Qu, Peiqing Yuan, Xinru Xu and Jingyi Yang

Catalysts 2026, 16(5), 418; https://doi.org/10.3390/catal16050418 - 2 May 2026

Abstract

Acid Orange 3 (AO3) is a widely used azo dye in leather, paper, and textile dyeing. Untreated direct discharge into water bodies severely threatens human health and aquatic ecosystems, yet efficient degradation remains challenging for conventional technologies. In this work, RuO₂/CeO [...] Read more.

Acid Orange 3 (AO3) is a widely used azo dye in leather, paper, and textile dyeing. Untreated direct discharge into water bodies severely threatens human health and aquatic ecosystems, yet efficient degradation remains challenging for conventional technologies. In this work, RuO₂/CeO₂ heterostructure was synthesized and immobilized on a Ti substrate via controlled hydrothermal and annealing treatments, yielding RuO₂/CeO₂@Ti electrode. The electrode showed electrocatalytic activity for the oxygen evolution reaction (OER) over a wide pH range. Under optimized conditions (47 mA/cm², pH 6, 0.25 M NaCl), 150 mg/L AO3 was degraded by 95.89% within 180 min. The degradation mechanism was elucidated by GC-MS and DFT (density functional theory) calculations. The degradation process was dominated by indirect oxidation, sequentially involving azo bond cleavage, heterocyclic ring opening, desulfurization, denitrification, benzene ring cleavage, and mineralization of small molecules into H₂O and CO₂. Full article

(This article belongs to the Section Electrocatalysis)

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19 pages, 3318 KB

Open AccessFeature PaperArticle

Alkali Metal-Promoted Au/TS-1 Bifunctional Catalyst for Highly Efficient and Stable Gas-Phase Propylene Epoxidation with H₂ and O₂ via In Situ-Generated H₂O₂

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

Catalysts 2026, 16(5), 417; https://doi.org/10.3390/catal16050417 - 2 May 2026

Abstract

Developing effective catalysts for the epoxidation of propylene with H₂ and O₂ holds significant scientific and industrial significance. This study synthesized a series of Au/TS-1 catalysts modified with alkali metals (Na⁺, Cs⁺) and carefully examined their impact [...] Read more.

Developing effective catalysts for the epoxidation of propylene with H₂ and O₂ holds significant scientific and industrial significance. This study synthesized a series of Au/TS-1 catalysts modified with alkali metals (Na⁺, Cs⁺) and carefully examined their impact on gas-phase propylene epoxidation, with particular attention to the role of anions. The optimal Au–CsC(1:10)/TS-1 catalyst (Cs₂CO₃ modified, Au/Cs molar ratio = 1:10) achieves a propylene conversion of 16.8%, a PO selectivity of 88.5%, an H₂ efficiency of 40.8%, a record PO formation rate of 383.9 g_po·kg_cat⁻¹·h⁻¹, and unprecedented long term stability (>380 h without deactivation). To the best of our knowledge, no previous study has simultaneously achieved such balanced and outstanding performance across all these key indicators. Comprehensive characterization reveals that Cs⁺ modification suppresses side reactions and coke formation, increases microporosity, tunes surface acid–base properties and hydrophobicity, restricts Au particle size, and stabilizes both Au⁰ and tetra coordinated Ti sites, thereby inhibiting H₂O₂ decomposition and PO isomerization while greatly enhancing reaction efficiency. This holistic advancement represents a significant leap forward for Au based catalysts in gas phase propylene epoxidation, offering both a theoretical foundation and practical guidance for the development of high performance epoxidation catalysts. Full article

(This article belongs to the Special Issue 15th Anniversary of Catalysts: Shaping a Sustainable Future Through Catalysis)

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36 pages, 2813 KB

Open AccessReview

The Use of Titanium Compounds as Supports and Cocatalysts/Additives for Low-Temperature Fuel Cell Catalysts

by Ermete Antolini

Catalysts 2026, 16(5), 416; https://doi.org/10.3390/catal16050416 - 2 May 2026

Abstract

Among different non-carbon materials, due to their high corrosion resistance and chemical stability, titanium-based compounds, such as TiO₂, TiN, TiC and Ti₃C₂T_x, are potential supports for PEMFC catalysts. In addition to its main function as [...] Read more.

Among different non-carbon materials, due to their high corrosion resistance and chemical stability, titanium-based compounds, such as TiO₂, TiN, TiC and Ti₃C₂T_x, are potential supports for PEMFC catalysts. In addition to its main function as a support, due to its catalytic properties, TiO₂ is also used as co-catalyst/additive in the catalyst layer. In this work, the use of titanium compounds as catalyst supports and co-catalysts in the membrane electrode assembly of PEMFCs is overviewed and discussed. Full article

(This article belongs to the Special Issue 15th Anniversary of Catalysts: Feature Papers in Electrocatalysis)

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29 pages, 4655 KB

Open AccessReview

Recent Advances in ZrO₂-Based Catalysts for the Catalytic Oxidation of Formaldehyde

by Fei Chang, Xinyi Cai, Jing Xu, Fuyu Hong, Hongyu Yang and Deng-Guo Liu

Catalysts 2026, 16(5), 415; https://doi.org/10.3390/catal16050415 - 2 May 2026

Abstract

Formaldehyde (HCHO) is a typical volatile organic compound (VOC) that poses significant risks to human health. Long-term exposure, even at low concentrations, has been associated with various malignant diseases, including nasopharyngeal, colon, and brain cancers. Common technologies for HCHO abatement include ventilation, adsorption, [...] Read more.

Formaldehyde (HCHO) is a typical volatile organic compound (VOC) that poses significant risks to human health. Long-term exposure, even at low concentrations, has been associated with various malignant diseases, including nasopharyngeal, colon, and brain cancers. Common technologies for HCHO abatement include ventilation, adsorption, photocatalysis, and catalytic oxidation. Among these methods, catalytic oxidation is regarded as the most promising due to its high removal efficiency, low cost, minimal energy consumption, and no toxic by-products. In recent years, supported catalysts with excellent room-temperature activity and high dispersibility have attracted considerable attention. These catalysts can usually be divided into two categories: noble metal catalysts and non-noble metal catalysts. Zirconia (ZrO₂) has become an ideal support owing to its advantages of high specific surface area, abundant and tunable acid–base sites, and strong metal–support interaction (SMSI). Various modification strategies have been developed to improve the catalytic performance of ZrO₂-based systems, such as the construction of phase interfaces and the stabilization of single-atom species. This review summarizes the recent research progress of ZrO₂-based systems for the catalytic oxidation of formaldehyde. It provides a detailed discussion of the physicochemical properties of ZrO₂ supports and the reaction mechanisms involved, and highlights achievements in crystal phase regulation, elemental doping, metal–support interaction, and composite modification. Finally, future challenges and development directions for these catalysts are also outlined. Full article

(This article belongs to the Special Issue Catalysis and Sustainable Green Chemistry)

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11 pages, 2876 KB

Open AccessArticle

UV-A LED Assisted Persulfate and Fenton Process for Efficient Sucralose Oxidation

by Alyson R. Ribeiro, Jose A. Casas, Juan A. Zazo and Jefferson E. Silveira

Catalysts 2026, 16(5), 414; https://doi.org/10.3390/catal16050414 - 2 May 2026

Abstract

This study investigates a combined advanced oxidation process (AOP) utilizing UVA-LED irradiation (365 nm) for the degradation of sucralose (SUC), a complex artificial sweetener that poses a challenge for wastewater treatment due to its resistance to conventional methods. A sequential treatment strategy was [...] Read more.

This study investigates a combined advanced oxidation process (AOP) utilizing UVA-LED irradiation (365 nm) for the degradation of sucralose (SUC), a complex artificial sweetener that poses a challenge for wastewater treatment due to its resistance to conventional methods. A sequential treatment strategy was employed. The initial step utilized UVA-activated persulfate (PS) at varying dosages (0.12–0.5 g/L) and UVA fluence rate (ranging from 20 to 100% of nominal output). The influence of natural water components (bicarbonate, chloride, sulfate, and nitrate) on PS activation was systematically analyzed. Notably, the substantial pH decrease during oxidation opened the possibility of replacing an amount of PS with the less expensive and more environmentally friendly hydrogen peroxide (H₂O₂) in the subsequent Fenton reaction. This second step employed a stoichiometric dosage of H₂O₂ (2.12 g/g COD) and varying Fe²⁺ concentrations (0.05–0.2 g/L), achieving a 95% overall mineralization within 60 min. The combined process incurred an approximate cost of 2.5€ per m³. This research contributes to the development of more effective and environmentally friendly wastewater treatment strategies for emerging contaminants. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment, 2nd Edition)

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17 pages, 3049 KB

Open AccessReview

The Recent Impact of Natural Deep Eutectic Solvents on Asymmetric Organocatalysis

by Maria B. Moura, Elisabete P. Carreiro, Pedro Paiva, Hans-Jürgen Federsel and Anthony J. Burke

Catalysts 2026, 16(5), 413; https://doi.org/10.3390/catal16050413 (registering DOI) - 2 May 2026

Abstract

Over the last 20 years, Deep-Eutectic Solvents (DES) have been making a significant impact in the field of chemistry, with applications in nanotechnology, biomass transformation, electrochemistry pharmaceuticals and a host of other applications that includes catalysis. Considering the importance of chiral organocatalysis for [...] Read more.

Over the last 20 years, Deep-Eutectic Solvents (DES) have been making a significant impact in the field of chemistry, with applications in nanotechnology, biomass transformation, electrochemistry pharmaceuticals and a host of other applications that includes catalysis. Considering the importance of chiral organocatalysis for the selective synthesis of drugs, pharmaceuticals and fragrances, etc. DESs were quickly harnessed as the media for carrying out organocatalytic transformations. In this review, we discuss some of the most important examples from the literature that have made an impact in the field over the last 5 years. A more recent development has been the incorporation of DESs in structured and self-organized gel-like assemblies that are known as EutectoGels. These soft structures offer a more defined and compact environment that can influence stereoselectivity by pre-organizing the reactants in three-dimensional space, and potential control the types of transition states that can be formed. Full article

(This article belongs to the Special Issue Catalytic Procedures for the Synthesis of Pharmaceutical Active Compounds in Deep Eutectic Solvents)

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28 pages, 2011 KB

Open AccessReview

Comprehensive Review on Titanium-Based Perovskite Nanoparticles and Heterojunctions for Photocatalytic Degradation of Emerging Contaminants

by Harry Lik Hock Lau, Nur Amirah S. Yussof, Nur Diana Bazilah Awang Idris, Rusydi R. Sofian, Syahirah Nabilah Aedy Aewandy, Nur Aisyah Abdul Munir, Nur Nabaahah Roslan, Eny Kusrini, Muhammad Nur and Anwar Usman

Catalysts 2026, 16(5), 412; https://doi.org/10.3390/catal16050412 - 2 May 2026

Abstract

Titanium-based perovskites have garnered significant attention for photocatalytic applications, particularly in the field of environmental remediation through the degradation of synthetic dyes and pharmaceuticals in aqueous solutions. This review paper aims to explore the synthesis methods, crystal structures, photoactivity, and photocatalytic performance of [...] Read more.

Titanium-based perovskites have garnered significant attention for photocatalytic applications, particularly in the field of environmental remediation through the degradation of synthetic dyes and pharmaceuticals in aqueous solutions. This review paper aims to explore the synthesis methods, crystal structures, photoactivity, and photocatalytic performance of titanium-based perovskites in degrading synthetic dye and pharmaceutical effluents in water. The unique advantages of titanium-based perovskites as photocatalysts, associated with their high redox potentials and excellent optical and electrical properties, are highlighted. Their limitations in visible light absorption and photocatalytic efficiency due to rapid charge carrier recombination are also discussed. Several strategies to overcome these limitations, such as surface modifications of the photocatalysts, metal and non-metal doping, the introduction of structure defects, the formation of heterojunctions with electron-accepting materials, and the deposition of plasmonic metal nanoparticles are systematically examined. This review also provides an overview of the photocatalytic degradation of dyes and pharmaceuticals as emerging contaminants, utilizing titanium-based perovskites as photocatalysts, to highlight their efficiency and potential for real-word applications. By covering research findings, current knowledge, and future perspectives, this review aims to stimulate advancements in the design and application of titanium-based perovskite photocatalysts. Full article

(This article belongs to the Special Issue 15th Anniversary of Catalysts—Recent Advances in Photocatalysis)

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36 pages, 1123 KB

Open AccessReview

Advances in Tar Steam Reforming Catalysts: A Review Focusing on Natural Minerals and Ni-Based Catalysts

by Xiaofei Sun, Dongwang Zhang, Rushan Bie and Man Zhang

Catalysts 2026, 16(5), 411; https://doi.org/10.3390/catal16050411 - 2 May 2026

Abstract

Biomass gasification technology is a crucial pathway for obtaining clean syngas and achieving efficient utilization of carbon resources. However, tar is one of the main factors restricting the industrialization of biomass gasification technology. Among various solutions, catalytic steam reforming is regarded as the [...] Read more.

Biomass gasification technology is a crucial pathway for obtaining clean syngas and achieving efficient utilization of carbon resources. However, tar is one of the main factors restricting the industrialization of biomass gasification technology. Among various solutions, catalytic steam reforming is regarded as the most promising solution. Currently, natural minerals and Ni-based catalysts have been demonstrated to be effective and economically viable for tar removal, which are widely used in industrial fluidized beds. Therefore, the basic reaction principles of tar steam reforming were briefly introduced. The development of tar steam reforming catalysts, focusing mainly on natural minerals and Ni-based catalysts, have been studied in this review. The catalytic cracking mechanisms of natural minerals such as dolomite and limestone, as well as the steam reforming mechanism of Ni-based catalysts, have been thoroughly summarized. In addition, the active sites of the catalysts, reaction pathways, and the essence of catalyst deactivation are discussed. Based on this, the catalytic effect of these two catalysts for steam reforming of tar in the fluidized bed was summarized. Further, the engineering challenges (such as mass transfer, wear, and continuous regeneration) and the corresponding process optimization measures were comprehensively reviewed, and future perspectives are discussed. Full article

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17 pages, 3718 KB

Open AccessFeature PaperArticle

Advancing Sustainable Aviation: Bimetallic Co-Mo Catalysts for Bio-Jet Fuel Production from Sunflower and Waste Cooking Oils

by Karoline K. Ferreira, Lucília S. Ribeiro and Manuel Fernando R. Pereira

Catalysts 2026, 16(5), 410; https://doi.org/10.3390/catal16050410 - 1 May 2026

Abstract

Co and Mo mono- and bimetallic catalysts supported on CNT-H-ZSM-5 composites were prepared and characterized using various techniques. The catalysts were evaluated for the conversion of sunflower oil (SO) into sustainable aviation fuel (SAF) hydrocarbons in the C₈–C₁₆ range. The [...] Read more.

Co and Mo mono- and bimetallic catalysts supported on CNT-H-ZSM-5 composites were prepared and characterized using various techniques. The catalysts were evaluated for the conversion of sunflower oil (SO) into sustainable aviation fuel (SAF) hydrocarbons in the C₈–C₁₆ range. The effects of reduction temperature and metal loading were the main parameters investigated in this study. The catalyst reduced at 600 °C promoted the formation of Mo₂C species, resulting in high SO conversion (84%), complete deoxygenation, and enhanced isomerization within the C₈–C₁₆ fraction. Optimal metal loadings (2.5 wt% Co and 8 wt% Mo) and the bimetallic configuration led to superior performance compared with monometallic catalysts and physical mixtures, clearly highlighting a synergistic effect between Co and Mo species. In contrast, when waste cooking oil was used as feedstock, lower conversion and reduced selectivity toward SAF-range hydrocarbons were observed, which were attributed to the higher complexity and impurity content of this residue feedstock. Full article

(This article belongs to the Special Issue Advanced Catalytic Materials for Greener Production of Chemicals, Biofuels, and Solar Fuels)

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12 pages, 3232 KB

Open AccessArticle

Ni-MOFs/CNTs Nanohybrid Catalysts for Thermoelectric Hydrogen Peroxide

by Linhao Zhang, Hong Liu, Jianming Zhang and Fagen Wang

Catalysts 2026, 16(5), 409; https://doi.org/10.3390/catal16050409 - 1 May 2026

Abstract

Harnessing low-grade thermal energy from industrial processes and the environment represents an attractive route toward sustainable chemical production. In this work, we report a thermoelectrocatalytic (TE-Catal) system capable of converting small temperature gradients into chemical energy for hydrogen peroxide (H₂O₂ [...] Read more.

Harnessing low-grade thermal energy from industrial processes and the environment represents an attractive route toward sustainable chemical production. In this work, we report a thermoelectrocatalytic (TE-Catal) system capable of converting small temperature gradients into chemical energy for hydrogen peroxide (H₂O₂) generation. A hybrid catalyst composed of nickel-based metal–organic frameworks (Ni-MOFs) nanoparticles integrated with carbon nanotubes (CNTs), Ni-MOFs/CNTs, was synthesized through a facile one-pot strategy. Under a temperature gradient, the thermoelectric response of the Ni-MOFs induces charge carrier generation through the Seebeck effect, enabling interfacial redox reactions that produce H₂O₂. However, rapid recombination of thermally generated carriers typically limits catalytic efficiency. By coupling Ni-MOFs with conductive CNTs networks, charge separation and transport are significantly enhanced due to the strong interfacial interaction and the high electrical conductivity of CNTs. As a result, the Ni-MOFs/CNTs nanohybrids exhibit greatly improved H₂O₂ generation rate of ~111.7 µmol g⁻¹ h⁻¹ compared with pristine Ni-MOFs (31.8 µmol g⁻¹ h⁻¹). Thermoelectric electrochemical measurements confirm that the CNT incorporation effectively promotes carrier migration and suppresses recombination. This study demonstrates the potential of MOF-based thermoelectric nanostructures for transforming waste heat into valuable chemical products. Full article

(This article belongs to the Special Issue Feature Papers in "Industrial Catalysis" Section, 3rd Edition)

16 pages, 2753 KB

Open AccessArticle

Surface-Subsurface Preference of S Species on Transition Metal Nanoparticles: A DFT Study

by Iskra Z. Koleva, Ivana Hristova, Boyana Sabcheva, Polya V. Koleva, Francesc Viñes and Hristiyan A. Aleksandrov

Catalysts 2026, 16(5), 408; https://doi.org/10.3390/catal16050408 - 1 May 2026

Abstract

Sulfur is a well-known catalyst poison, particularly for catalysts based on transition metals. Herein, we studied the adsorption of sulfur species on small nanoparticles (~1 nm in size) of the face centered cubic (fcc) transition metals (Rh, Ir, Ni, Pd, Pt, Cu, Ag, [...] Read more.

Sulfur is a well-known catalyst poison, particularly for catalysts based on transition metals. Herein, we studied the adsorption of sulfur species on small nanoparticles (~1 nm in size) of the face centered cubic (fcc) transition metals (Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au) using density functional theory (DFT) modeling. At low sulfur coverage (one S atom per nanoparticle), sulfur preferentially occupies the surface hollow sites of the nanoparticles. At higher coverage, however, the subsurface diffusion of S in Ni, Pd, and Ag nanoparticles becomes energetically favorable with low activation energies. Among the considered metals, sulfur binds most strongly to Rh and Ir, and most weakly to Ag and Au. The present results shed light on the facility of S-poisoning on such metal nanoparticles, either by surface blocking or by underlying sulfurization of the metal. Full article

(This article belongs to the Special Issue Catalysis and Sustainable Green Chemistry)

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