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17 pages, 3487 KiB

Open AccessFeature PaperArticle

The Formation of Mn-Ce-Zr Oxide Catalysts for CO and Propane Oxidation: The Role of Element Content Ratio

by Tatyana N. Afonasenko, Daria V. Yurpalova, Zakhar S. Vinokurov, Andrey A. Saraev, Egor E. Aidakov, Valeriya P. Konovalova, Vladimir A. Rogov and Olga A. Bulavchenko

Catalysts 2023, 13(1), 211; https://0-doi-org.brum.beds.ac.uk/10.3390/catal13010211 - 16 Jan 2023

Cited by 5 | Viewed by 1667

Abstract

The MnO_х-ZrO₂-CeO₂ oxide catalysts were synthesized by co-precipitation method with varying (1) Zr/Zr + Ce molar ratio at constant manganese content of 0.3; (2) manganese content at constant Zr/Ce molar ratio of 1; (3) Mn/Mn + Zr molar [...] Read more.

The MnO_х-ZrO₂-CeO₂ oxide catalysts were synthesized by co-precipitation method with varying (1) Zr/Zr + Ce molar ratio at constant manganese content of 0.3; (2) manganese content at constant Zr/Ce molar ratio of 1; (3) Mn/Mn + Zr molar ratio at constant Ce content of 0.5. Catalysts are characterized by XRD, N₂ adsorption, TPR, and XPS. The catalytic activity of all the series was tested in the CO and propane oxidation reactions. In contrast to the variation of the manganese content, the Zr/Zr + Ce molar ratio does not significantly affect the catalytic properties. The dependence of the catalytic activity in CO oxidation on the manganese content has a «volcano» shape, and the best catalytic performance is exhibited by the catalyst with Mn/(Zr + Ce) = 1. In the case of propane oxidation reaction, there is «sigma» like dependence, activity increases with increase of Mn/(Mn + Zr + Ce) molar ratio up to 0.3, stabilizing with a further increase in the manganese content. XRD and XPS have shown that with an increase of the Mn concentration in the MnO_x-ZrO₂-CeO₂ catalysts, the amount of crystalline manganese oxides such as Mn₂O₃ and Mn₃O₄, as well as the surface concentration of Mn cations, increases. While the content of Mn_xZr_yCe_1-x-yO₂ solid solution decreases, the concentration of manganese cations (x) in volume of Mn_xZr_yCe_1-x-yO₂ mixed oxide grows. The maximum activity in CO oxidation corresponds to the balance between the amount of the solid solution and the concentration of manganese cations in the volume of mixed oxide. The propane oxidation reaction is less sensitive to the state of manganese ion rather than to its amount. In this case, a decrease in the content of the Mn_xZr_yCe_1-x-yO₂ solid solution with increase in manganese amount in catalyst is compensated by an increase in content of crystalline manganese oxides and the surface concentration of manganese. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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15 pages, 3132 KiB

Open AccessArticle

Facile Hydrothermal Synthesis of Cu₂MoS₄ and FeMoS₄ for Efficient Adsorption of Chlortetracycline

by Junhui Zhou, Keyu Zhu, Yong Wang, Peng Cui, Linhua Zhu, Haofeng Wu, Mingqing Hua, Yan Huang, Guiling Luo, Yanhong Chao and Wenshuai Zhu

Catalysts 2023, 13(1), 61; https://0-doi-org.brum.beds.ac.uk/10.3390/catal13010061 - 28 Dec 2022

Cited by 3 | Viewed by 1385

Abstract

Contamination of antibiotics in an aqueous environment has attracted wide attention. Developing high-efficiency adsorbents for antibiotics removal is urgent. In this work, two kinds of ternary transition metal chalcogenides—Cu₂MoS₄ and FeMoS₄ with superior adsorption performance were prepared by a [...] Read more.

Contamination of antibiotics in an aqueous environment has attracted wide attention. Developing high-efficiency adsorbents for antibiotics removal is urgent. In this work, two kinds of ternary transition metal chalcogenides—Cu₂MoS₄ and FeMoS₄ with superior adsorption performance were prepared by a facile hydrothermal synthesis method. The microstructure and physicochemical properties of the adsorbents were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The as-prepared Cu₂MoS₄ and FeMoS₄ were found to have dramatic potential for the adsorption of chlortetracycline (CTC) in an aqueous solution with an extremely high adsorption capacity. The Langmuir maximum adsorption capacity of Cu₂MoS₄ and FeMoS₄ to CTC can reach 1203.81 and 2169.19 mg/g, respectively, which goes far beyond the common adsorbents as reported. Moreover, the adsorption kinetics, thermodynamics as well as adsorption mechanism were examined in detail by a batch of adsorption experiments. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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12 pages, 3904 KiB

Open AccessArticle

Synergistic Effect in Plasmonic CuAu Alloys as Co-Catalyst on SnIn₄S₈ for Boosted Solar-Driven CO₂ Reduction

by Zhengrui Yang, Jinman Yang, Kefen Yang, Xingwang Zhu, Kang Zhong, Ming Zhang, Haiyan Ji, Minqiang He, Huaming Li and Hui Xu

Catalysts 2022, 12(12), 1588; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12121588 - 06 Dec 2022

Cited by 2 | Viewed by 1459

Abstract

The photoreduction of CO₂ to chemical fuels represents a promising technology to mitigate the current energy dilemma and global warming problems. Unfortunately, the original photocatalysts suffer from many side reactions and a poor CO₂ conversion efficiency. The rational combination of active [...] Read more.

The photoreduction of CO₂ to chemical fuels represents a promising technology to mitigate the current energy dilemma and global warming problems. Unfortunately, the original photocatalysts suffer from many side reactions and a poor CO₂ conversion efficiency. The rational combination of active co-catalyst with pristine photocatalysts for promoting the adsorption and activation of CO₂ is of vital importance to tackle this grand challenge. Herein, we rationally designed a SnIn₄S₈ nanosheet photocatalyst simultaneously equipped with CuAu alloys. The experimental results proved that the CuAu alloy can trap the electrons and enhance the separation and transport efficiency of the photogenerated carrier in the photocatalyst, alleviating the kinetical difficulty of the charge transfer process because of the preferable localized surface plasmon resonance (LSPR). Furthermore, the CuAu alloy works as the synergistic site to increase the CO₂ adsorption and activation capacity. The optimized CuAu-SnIn₄S₈ photocatalyst exhibited a superior performance with CO generation rates of 27.87 μmol g⁻¹ h⁻¹ and CH₄ of 7.21 μmol g⁻¹ h⁻¹, which are about 7.6 and 2.5 folds compared with SnIn₄S₈. This work highlights the critical role of alloy cocatalysts in boosting a CO₂ activation and an efficient CO₂ reduction, thus contributing to the development of more outstanding photocatalytic systems. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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11 pages, 3641 KiB

Open AccessArticle

Novel and Green Synthesis of Nitrogen-Doped Carbon Cohered Fe₃O₄ Nanoparticles with Rich Oxygen Vacancies and Its Application

by Xinxiang Cao, Huijie Zhu, Ben W.-L. Jang, Arash Mirjalili, Chunlai Yang, Luoqing Jiang, Siye Tang, Junjie Zhang, Juanjuan Qin and Long Zhang

Catalysts 2022, 12(6), 621; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12060621 - 06 Jun 2022

Cited by 3 | Viewed by 1781

Abstract

A one-pot and green synthesis methodology was successfully designed to prepare nitrogen-doped carbon (NC) cohered Fe₃O₄ nanoparticles with rich oxygen vacancies (Fe₃O₄-OVs/NC). The preparation was achieved via cold-atmospheric-pressure air plasma using Fe₂O₃ nanoparticles [...] Read more.

A one-pot and green synthesis methodology was successfully designed to prepare nitrogen-doped carbon (NC) cohered Fe₃O₄ nanoparticles with rich oxygen vacancies (Fe₃O₄-OVs/NC). The preparation was achieved via cold-atmospheric-pressure air plasma using Fe₂O₃ nanoparticles as the only precursor, and pyridine as the carbon and nitrogen source. Systematic characterization results of the as-prepared Fe₃O₄-OVs/NC confirmed the transition from Fe₂O₃ to Fe₃O₄, along with the generation of oxygen vacancies, while preserving the original needle-like morphology of Fe₂O₃. Moreover, the results indicated the formation of the NC attaching to the surface of the formed Fe₃O₄ nanoparticles with a weight percent of ~13.6%. The synthesized nanocomposite was further employed as a heterogeneous Fenton catalyst to remove phenol from an aqueous solution. The material has shown excellent catalytic activity and stability, demonstrating a promising application for wastewater treatment. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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13 pages, 4600 KiB

Open AccessArticle

Study of Intermolecular Interaction between Small Molecules and Carbon Nanobelt: Electrostatic, Exchange, Dispersive and Inductive Forces

by Chen Lu, Panpan Chen, Cunlei Li and Jingang Wang

Catalysts 2022, 12(5), 561; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12050561 - 19 May 2022

Cited by 4 | Viewed by 2054

Abstract

The conjugated structure of carbon is used in chemical sensing and small molecule catalysis because of its high charge transfer ability, and the interaction between carbon materials and small molecules is the main factor determining the performance of sensing and catalytic reactions. In [...] Read more.

The conjugated structure of carbon is used in chemical sensing and small molecule catalysis because of its high charge transfer ability, and the interaction between carbon materials and small molecules is the main factor determining the performance of sensing and catalytic reactions. In this work, Reduced Density Gradient (RDG) and Symmetry-Adapted Perturbation Theory (SAPT) energy decomposition methods were used in combination to investigate the heterogeneity of catalytic substrates commonly used in energy chemistry with [6, 6] the carbon nanobelt ([6, 6] CNB, the interaction properties and mechanisms inside and outside the system). The results show that most of the attractive forces between dimers are provided by dispersive interactions, but electrostatic interactions cannot be ignored either. The total energy of the internal adsorption of [6, 6] CNB was significantly smaller than that of external adsorption, which led to the small molecules being more inclined to adsorb in the inner region of [6, 6] CNB. The dispersive interactions of small molecules adsorbed on [6, 6] CNB were also found to be very high. Furthermore, the dispersive interactions of the same small molecules adsorbed inside [6, 6] CNB were significantly stronger than those adsorbed outside. In [6, 6] CNB dimers, dispersion played a major role in the mutual attraction of molecules, accounting for 70% of the total attraction. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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21 pages, 9651 KiB

Open AccessArticle

Modified 7-Chloro-11H-indeno[1,2-b]quinoxaline Heterocyclic System for Biological Activities

by Nakul Kumar, Gajendra Kumar Inwati, Emad M. Ahmed, Chhagan Lal, Bharat Makwana, Virendra K. Yadav, Saiful Islam, Hyun-Jo Ahn, Krishna K. Yadav and Byong-Hun Jeon

Catalysts 2022, 12(2), 213; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12020213 - 11 Feb 2022

Cited by 10 | Viewed by 2334

Abstract

Recent advances in functionalized organic Spiro heterocyclic compounds composed of nitrogen bonded five- and six-membered rings have been made, establishing them as a synthetic target in organic-based biomedical applications. In this work, we report a synthesis of spirocyclic compounds under a one-pot reaction [...] Read more.

Recent advances in functionalized organic Spiro heterocyclic compounds composed of nitrogen bonded five- and six-membered rings have been made, establishing them as a synthetic target in organic-based biomedical applications. In this work, we report a synthesis of spirocyclic compounds under a one-pot reaction using 1,3-dipolar cycloaddition in a regio and diastereoselective manner. The higher atomic economy with higher yield (95%) and regio and stereoselectivity were achieved by a multi-component reaction of L-proline (1), Indenoquinoxaline (2), and the dipolarophile of malononitrile (3) solvents followed by reflux conditions. The reaction intermediate comprised azomethineylides derived from reactive primary amines, and the spiro derivatives were synthesized up to a ≈ 95% yield. The structural and characteristic chemical components of the as-prepared Spiro compounds were characterized by ¹H-NMR, FTIR, and Mass spectroscopy. The functionalized spiro-pyrrolizidines were found to be effective for biological uses by considering their in vitro screening and antimicrobial impacts. Spiro constituents were found to be much more effective for Gram-positive bacteria due to the stronger lipophilic character of the molecules, and they resulted feasible membrane permeation in a biological system. Based on the planarity geometry of the Spiro pyrrolizidines, meta-substitution possesses steric hindrance and hence shows less effectiveness compared to para-substitution on the same nucleus, which shows a marginal steric effect. The biological studies showed that the derived spiro heterocyclic systems have an inhibitory effect of 50%. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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10 pages, 3497 KiB

Open AccessArticle

Synthesis, Crystal Structure, and Electrochemical Properties of an Isopolyoxovanadate Compound Modified Transition-Metal Complex Based on [V₄O₁₂]⁴⁻

by Yongxiu Wang, Bingjie Zhang, Huili Guo, Yanhua Fan, Haiyan Li, Jingyu Pang, Dongbin Dang and Yan Bai

Catalysts 2022, 12(2), 108; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12020108 - 18 Jan 2022

Cited by 2 | Viewed by 1620

Abstract

A new isopolyoxovanadate compound [Zn(phen)₃]₂·(V₄O₁₂)·phen·20H₂O (phen = 1,10-phenathroline) (1) has been synthesized in aqueous solution and characterized using IR and UV/Vis spectroscopy, elemental analysis, thermal gravimetric analysis, powder, single-crystal X-ray diffractions, [...] Read more.

A new isopolyoxovanadate compound [Zn(phen)₃]₂·(V₄O₁₂)·phen·20H₂O (phen = 1,10-phenathroline) (1) has been synthesized in aqueous solution and characterized using IR and UV/Vis spectroscopy, elemental analysis, thermal gravimetric analysis, powder, single-crystal X-ray diffractions, and field emission scanning electron microscopy. The molecular structure of 1 exists as two kinds of [V₄O₁₂]⁴⁻ polyoxoanions: distorted chair-like and coplanar conformations, two independent [Zn(phen)₃]²⁺ units and free phen. In the solid state, compound 1 forms a stable three-dimensional supramolecular structure through electrostatic interactions, π–π stacking interactions and multiform hydrogen bonds. The electrocatalytic activity and determination of DA of compound 1 have been studied by cyclic voltammetry and differential pulse voltammetry, respectively. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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Review

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13 pages, 4281 KiB

Open AccessReview

Catalytically Active Advanced Two-Dimensional Ultrathin Nanomaterials for Sustainable Energy

by FuJie Liu, Chao Wang, Ming Zhang and Mengxia Ji

Catalysts 2022, 12(10), 1167; https://0-doi-org.brum.beds.ac.uk/10.3390/catal12101167 - 03 Oct 2022

Viewed by 1429

Abstract

Advanced two-dimensional (2D) ultrathin nanomaterials’ unique structural and electronic properties and their applications in the photo-, photoelectro-, and electro-catalysis fields present timely topics related to the development of sustainable energy. This critical review briefly summarizes the state-of-the-art progress on 2D ultrathin nanomaterials. In [...] Read more.

Advanced two-dimensional (2D) ultrathin nanomaterials’ unique structural and electronic properties and their applications in the photo-, photoelectro-, and electro-catalysis fields present timely topics related to the development of sustainable energy. This critical review briefly summarizes the state-of-the-art progress on 2D ultrathin nanomaterials. In this mini review, we started with the synthesis of 2D ultrathin nanomaterials. Then, various strategies for tailoring the electronic and configuration structures of these nanomaterials in the new energy catalysis field are surveyed, where the emphasis is mainly on structure-activity relationships. The advancements of versatile 2D ultrathin nanomaterials in the fields of hydrogen evolution, carbon dioxide conversion, and dinitrogen fixation for sustainable energy were also discussed. Finally, the existing challenges and future research directions in this promising field are presented. Full article

(This article belongs to the Special Issue Functional Materials for Application in Adsorption & Catalysis)

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