Subjects -> METALLURGY (Total: 58 journals)
Showing 1 - 10 of 10 Journals sorted alphabetically
Acta Metallurgica Slovaca     Open Access  
Advanced Device Materials     Open Access   (Followers: 3)
American Journal of Fluid Dynamics     Open Access   (Followers: 48)
Archives of Metallurgy and Materials     Open Access   (Followers: 9)
Asian Journal of Materials Science     Open Access   (Followers: 5)
Canadian Metallurgical Quarterly     Hybrid Journal   (Followers: 20)
Complex Metals     Open Access   (Followers: 2)
Corrosion Communications     Open Access  
Energy Materials : Materials Science and Engineering for Energy Systems     Hybrid Journal   (Followers: 19)
Handbook of Magnetic Materials     Full-text available via subscription   (Followers: 2)
Indian Journal of Engineering and Materials Sciences (IJEMS)     Open Access   (Followers: 10)
International Journal of Metallurgy and Alloys     Full-text available via subscription   (Followers: 3)
International Journal of Metals     Open Access   (Followers: 6)
International Journal of Minerals, Metallurgy, and Materials     Hybrid Journal   (Followers: 8)
International Journal of Mining and Geo-Engineering     Open Access  
Ironmaking & Steelmaking     Hybrid Journal   (Followers: 4)
ISIJ International - Iron and Steel Institute of Japan     Full-text available via subscription   (Followers: 23)
JOM Journal of the Minerals, Metals and Materials Society     Hybrid Journal   (Followers: 32)
Journal of Advanced Joining Processes     Open Access   (Followers: 1)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Journal of Cluster Science     Hybrid Journal  
Journal of Iron and Steel Research International     Hybrid Journal   (Followers: 7)
Journal of Materials & Metallurgical Engineering     Full-text available via subscription   (Followers: 1)
Journal of Materials Processing Technology     Hybrid Journal   (Followers: 19)
Journal of Metallurgical Engineering     Open Access   (Followers: 2)
Journal of Sustainable Metallurgy     Hybrid Journal   (Followers: 3)
Materials Science and Metallurgy Engineering     Open Access   (Followers: 7)
Metallurgical and Materials Engineering     Open Access  
Metallurgical and Materials Transactions A     Hybrid Journal   (Followers: 41)
Metallurgical and Materials Transactions B     Hybrid Journal   (Followers: 30)
Metallurgical and Materials Transactions E     Full-text available via subscription   (Followers: 2)
Metallurgical Research & Technology     Full-text available via subscription  
Metallurgical Research and Technology     Full-text available via subscription   (Followers: 6)
Metallurgy and Foundry Engineering     Open Access   (Followers: 1)
Mining, Metallurgy & Exploration     Hybrid Journal  
Powder Diffraction     Full-text available via subscription   (Followers: 1)
Powder Metallurgy     Hybrid Journal   (Followers: 33)
Powder Metallurgy and Metal Ceramics     Hybrid Journal   (Followers: 7)
Powder Metallurgy Progress     Open Access   (Followers: 5)
Rare Metals     Hybrid Journal   (Followers: 2)
Revista de Metalurgia     Open Access  
Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica     Open Access  
Revista Remetallica     Open Access  
Russian Metallurgy (Metally)     Full-text available via subscription   (Followers: 4)
Science and Technology of Welding and Joining     Hybrid Journal   (Followers: 4)
Soldering & Surface Mount Technology     Hybrid Journal   (Followers: 1)
Stainless Steel World     Full-text available via subscription   (Followers: 17)
Transactions of the IMF     Hybrid Journal   (Followers: 14)
Transactions of the Indian Institute of Metals     Hybrid Journal   (Followers: 4)
Tungsten     Hybrid Journal  
Universal Journal of Materials Science     Open Access   (Followers: 1)
Welding in the World     Hybrid Journal   (Followers: 4)
Welding International     Hybrid Journal   (Followers: 7)
Вісник Приазовського Державного Технічного Університету. Серія: Технічні науки     Open Access  
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Tungsten
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  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2661-8028 - ISSN (Online) 2661-8036
Published by Springer-Verlag Homepage  [2469 journals]
  • Incorporation of polyoxometalate-based acid–base pair into a sulfonated
           MIL-101 for achieving proton-conduction materials with high proton
           conductivity and high stability

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      Abstract: Abstract Currently, it is of great significance to develop new proton-conduction materials with high proton conductivity, high stability, and good conducting durability to meet the demands of fuel cell and sensors. Herein, we prepared two composites DETA-HPW@MIL-101-SO3H 1 and TETA-HPW@MIL-101-SO3H 2 (DETA = diethylenetriamine, HPW = H3PW12O40·xH2O, MIL = Material Institut Lavoisier, TETA = triethylenetetramine) by encapsulating polyoxometalate (POM) and organic amine into a sulfonated MIL-101 through a step-by-step dipping method. Delightedly, 1 and 2 have high proton conductivities of 6.4 × 10−2 and 2.9 × 10−2 S·cm−1 at 65 °C and 95% relative humidity (RH), respectively, which can be attributed to the fast proton transfer among acid–base pairs formed between HPW and organic amine as well between sulfonic acid and organic amine. Moreover, the time-dependent test in proton conductivity displays that their proton-conduction properties have good stability and durability, which benefit from that the electrostatic interactions among acid–base pairs and the limitation of opening size of MIL-101-SO3H make HPW and organic amine stably exist in the cages of MIL-101-SO3H. The remarkable proton-conduction properties (high proton conductivity and high stability) of the two composites make them become promising proton-conduction materials.
      PubDate: 2022-06-01
       
  • Effect of Na(I)-H2O clusters on self-assembly of sandwich-type
           U(VI)-containing silicotungstates and the efficient catalytic activity for
           the synthesis of substituted phenylsulfonyl-1H-pyrazoles

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      Abstract: Abstract In this study, a sandwich-type uranium(VI)-containing silicotungstate KNa11H2(H2O)30[Na(UO2)(SiW9O34)]2·8H2O (1) with new three-dimensional (3D) structure was synthesized and characterized using single-crystal X-ray diffraction, Fourier transform infrared, Raman, solid-state ultraviolet–visible diffuse reflection spectra, thermogravimetric analysis and powder X-ray diffraction. Single crystal analysis revealed that the Na(I)-H2O clusters in 1 showed a two-dimensional structure similar to (4,4)-network and resulted in the formation of a new 3D structure of 1. In addition, it was notable that 1 presented excellent catalytic activity for the synthesis of substituted phenylsulfonyl-1H-pyrazoles via the cyclization reaction of 1,3-diketones with various substituted benzenesulfonyl hydrazides.
      PubDate: 2022-06-01
       
  • Insight into hexanuclear peroxotantalum complexes: synthesis,
           characterization, and efficient catalyst for amidation reaction

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      Abstract: Abstract Polyoxometalates (POMs), large oxoanions of the group 5 and 6 elements, attract attention due to their use as oxidation-stable catalysts and ligands. Different from the well-known V, Mo, and W POMs, the group V POMs of Ta assemble and are stable only in highly alkaline solution rather than acidic solution. In this paper, we successfully synthesized and structurally characterized two unprecedented peroxotantalum-containing clusters, KNa2[HSe2(TaO2)6(OH)4(H2O)2O13]·15H2O (1) and Cs2K1.5Na1.5[Se4(TaO2)6 (OH)3O18]·17H2O (2), which comprises a 6-peroxo-6-tantalum core stabilized by two and four selenite centers, respectively. The simple, one-pot synthesis of 1 and 2 involving addition of sodium selenite into the acidified hexatantalate aqueous solution in the presence of hydrogen peroxide could represent a general procedure for incorporating heteroatoms into peroxo-polyoxotantalate species, thus opening new possibilities for this emergent branch of polyoxotantalate chemistry. Moreover, the catalytic properties of these two compounds were investigated using succinic anhydride and phenylamine as the model substrate, and compound 2 presents excellent catalytic activity in the amidation reactions of anhydrides and amines.
      PubDate: 2022-06-01
       
  • A tri-vanadium-capped Keggin phosphomolybdate: synthesis,
           characterization, photocatalytic and bifunctional electrocatalytic
           properties

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      Abstract: Abstract A purely inorganic tri-vanadium-capped Keggin phosphomolybdate [Na3PMo12V3O43]·4H2O (compound 1) has been synthesized by hydrothermal means and characterized via powder X-ray diffraction, infrared spectrum, thermogravimetric analysis, single-crystal X-ray diffraction, scanning electron microscope, ultraviolet–visible absorption spectroscopy, ultraviolet–visible diffuse reflection spectra as well as electrochemical cyclic voltammetry tests. The structure analysis displays that compound 1 is a symmetric tri-vanadium-capped cluster through six half occupancy {VO5} units. Compound 1 remains a purely inorganic Keggin phosphomolybdate, which presents electrocatalytic properties for the oxidization of ascorbic acid and reduction of H2O2. At the same time, it possesses high-efficiency degradation capability for typical methylene blue, Rhodamine B and methyl orange dyes under ultraviolet light.
      PubDate: 2022-06-01
       
  • A polyoxometalate based electrochemical sensor for efficient detection of
           L-cysteine

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      Abstract: Abstract L-cysteine (L-cys), as an important sulfur-containing amino acid, plays an indispensable role in biological systems. Too low and excessively high ratio of L-cys will cause harm to the function of human organs. Therefore, it is very necessary to develop efficient methods to detect it in multifarious samples. This paper has built an electrochemical sensor by combining Keggin-type polyoxometalate (PMo9V3) and cobalt tetrasulfonate (II) phthalocyanine (CoTsPc) on indium tin oxide electrodes using the layer-level self-assembly technology for efficiently detection of L-cys. The assembly process and surface morphology of the modified electrode was characterized by ultraviolet–visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope, and atomic force microscopy. The conditions of electro-catalysed oxidation of L-cys were optimized by cyclic voltammetry, and the kinetic electrochemical parameters were also evaluated by electrochemical impedance spectra. Furthermore, the sensing performance of the modified electrode was explored using amperometry. The proposed electrochemical L-cys sensor was found to have superior sensing performance with a range of linear response of 2.5 × 10–7 to 1.7 × 10–4 mol·L−1 and 1.7 × 10−4 to 39.5 × 10−4 mol·L−1, the detection limit of 1.0 × 10–7 mol·L−1 (signal/noise = 3), and satisfactory anti-interference ability. Consequently, the fabricated sensor has the potential to be applied in laboratory practices for L-cys deterimination in commercial drinks.
      PubDate: 2022-06-01
       
  • A Lindqvist-type [W6O19]2‒ organic–inorganic compound: synthesis,
           characterization, antibacterial activity and preliminary studies on the
           mechanism of action

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      Abstract: Abstract In this paper, a new organic–inorganic hybrid compound [Co(L)2]2[W6O19](1) (HL = 2-acetylpyridine thiosemicarbazone) was prepared and characterized. The compound 1 exhibits remarkable antibacterial activity by determination of minimum inhibitory concentration (MIC) against Staphylococcus aureus (S. aureus, 0.06 µg·mL−1) and Escherichia coli (E. coli, 0.24 µg·mL−1), respectively. Furthermore, the potential mechanism of compound 1 was studied in detail. The potential causes of bacteria death were cell wall/membrane disruption, inhibition of intracellular respiratory chain dehydrogenases (RCD) activity, destruction of reactive oxygen species (ROS) and depletion of glutathione (GSH).
      PubDate: 2022-06-01
       
  • Effects of hydrogen charging and deformation on tensile properties of a
           multi-component alloy for nuclear applications

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      Abstract: In this study, the influence of hydrogen charging and deformation on the tensile behavior of a 60Fe–12Cr–10Mn–15Cu–3Mo multi-component alloy was investigated using electron microscopy and positron annihilation lifetime spectroscopy. The results show that hydrogen-induced vacancy clusters found in the electrochemically charged hydrogen specimens are responsible for crack initiation. Upon ingress to the microstructure, hydrogen promotes the formation of cell-structured dislocations that are beneficial for the improvement of tensile strength. In addition, hydrogen embrittlement can be mitigated by dislocations that can hinder hydrogen mobility in the deformed specimens.
      PubDate: 2022-05-09
       
  • Effect of surface modification on thermal expansion of Zr2WP2O12/aromatic
           polyimides based composites

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      Abstract: Abstract Surface modification is a fascinating way to improve the compounding effect between inorganic fillers and polymers. In this study, zirconium tungsten phosphate (ZWP) with negative thermal expansion was surface modified by silane coupling agent 3-(Trimethoxysilyl)propyl methacrylate. The effects of surface modification and the modification mechanism were analyzed in detail by X-ray diffractometer, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal mechanical analysis. The surface modification could effectively reduce the thermal expansion properties of the composite. When the added amount of 3-methacryloxypropyl trimethoxysilaneSilane (trade name: KH570) is 0.50 wt%, the thermal expansion coefficient of ZWP/Aromatic polyimide composite decreased by 9.76%. The surface modification also can effectively improve the dielectric performance of aromatic polyimides. The present work provides one new way to improve the thermal expansion behavior of composites.
      PubDate: 2022-04-29
       
  • Assembly of selenoniobate–vanadoniobate double-anion
           heteropolyoxoniobate: synthesis, structure, and magnetic property

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      Abstract: Abstract Recently, continuous interests and persisting efforts on heteropolyniobate have been dedicated to its preparation and exploration. In this work, a novel Se-centred heteropolyniobate, [H2SeNb12(VO)4O40][Cu(en)2]2{[VNb12(VO)4O40][Cu(en)2]4}0.5·39H2O (en = ethanediamine), was synthesized. The compound was synthesized in aqueous solution by reacting the K7HNb6O19·13H2O with a mixture of vanadate (V) and selenite (IV) source, which consists of two polyanions, i.e., V-centred one and Se-centred another. The architecture was characterized by infrared spectra, thermogravimetric analysis, X-ray powder diffraction spectroscopy, ultraviolet–visible and X-ray photoelectron spectroscopy. Further, the magnetic property shows the antiferromagnetic interaction of the compound.
      PubDate: 2022-04-27
       
  • First-principles study of substitutional solute and carbon interactions in
           tungsten

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      Abstract: Abstract Interstitial carbon and substitutional transition metal (TM) solutes are common impurities in tungsten and tungsten alloys. Yet, despite its important role in affecting mechanical and irradiation performances of tungsten, the interplay between these impurities remains largely unknown. In this work, we performed systematic first-principles simulations to study the interaction between carbon and TM solutes. By calculating related binding energies, we found that interplay between carbon and TM solutes is dominated by elastic interactions, with carbon generally showing attractions to TM solutes. Further, including vacancies in our calculation, we found that all solute–vacancy–carbon complexes are energetically stable with respect to associated point defects. Additional analysis shows that vacancy–carbon binding is generally weakened by TM solutes, while carbon also in turn reduces the binding energy between vacancy and TM solutes. Based on these binding energy results, we, respectively, evaluated the effect of solute and carbon on each other’s diffusion behaviors. We found that Cr and V slightly decrease the carbon diffusivity while other commonly seen TM solutes show little impacts on carbon diffusion, and we also expect carbon to slow down vacancy-mediated TM solute diffusion in tungsten.
      PubDate: 2022-04-19
       
  • Co3O4/stainless steel catalyst with synergistic effect of oxygen vacancies
           and phosphorus doping for overall water splitting

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      Abstract: Abstract The electrolysis of water into hydrogen and oxygen provides an effective means of storing electrical energy indirectly. The current challenge is to design an optimal catalyst that exhibits low overpotentials, long-term stability, universal availability, and only uses inexpensive materials. Herein, a Co3O4 nanoflower/stainless steel (P-Ov-Co3O4/SS) catalyst with both oxygen vacancies (Ovs) and phosphorus doping was perfectly prepared via a simple three-step method. The Ovs promoted charge transfer and accelerated the electrocatalysis, while P finely tuned the surface charge state. This resulted in numerous active sites for catalysis, and the synergistic effect of phosphorus doping and oxygen vacancies was finely demonstrated. The resultant electrocatalyst exhibited low hydrogen evolution overpotentials of 118 mV (− 10 mA·cm−2) and 242 (− 200 mA·cm−2), as well as oxygen evolution overpotentials of 327 mV (100 mA·cm−2) and 370 mV (200 mA·cm−2), owing to the excellent synergistic effect of the Ovs and low-temperature phosphating. Moreover, P-Ov-Co3O4/SS//P-Ov-Co3O4/SS exhibited a low water splitting voltage of 1.681 V at 20 mA·cm−2. These findings will enable the synthesis of novel high-performance electrocatalysts for overall water splitting.
      PubDate: 2022-04-13
       
  • Compositional study of δ-NbN film by Auger electron microscopy

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      Abstract: Abstract The chemical stoichiometry on the surface of superconducting δ-NbN thin films is of great importance for their application. Here, we fabricated the δ-NbN thin films on SiO2/Si substrate by DC sputtering method. The film was characterized using X-ray diffraction (XRD) and atomic force microscopy (AFM). Transport properties were measured to reveal the field dependent superconducting transition temperature. Both XRD and electrical measurement show high crystallinity of δ-NbN phase. A homogeneous and smooth surface morphology was measured by AFM. Auger electron spectroscopy (AES) was applied to analyze the composition along the depth of the film. The evolution of Auger peak profile, heights and nitride stoichiometry at the film surface is discussed. The current study provides a more thorough understanding of complex chemical compositions of δ-NbN thin films.
      PubDate: 2022-03-22
       
  • Deposition of nano-crystalline tungsten carbide powders from gaseous
           WO2(OH)2

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      Abstract: Abstract Lower WC grain sizes in the nanometer range have positive effects on the properties of hardmetals (e.g., hardness), but the established production processes of WC are limited to grain sizes of about 150 nm. To produce WC powder with grain sizes in the lower nanometer range, an alternative WC production process based on the chemical vapor transport (CVT) reaction of WO3 and H2O forming gaseous WO2(OH)2 at about 1100 °C, followed by a carburation reaction with H2/CH4-gas mixtures was investigated. The influences of different process parameters such as furnace temperature, humidity and gas flows were investigated to improve the process. With the right set of parameters the produced powder consisted mainly of agglomerated WC grains with a size of about 5 nm. Beside the common hexagonal WC phase, the cubic WC1−x phase was stabilized due to the small crystallite sizes. In addition, a thin layer of amorphous carbon was present on the powder surface due to the catalytic methane decomposition on the WC surface. The amount of oxidic and metallic residues in the product powder was minimized with the parameter optimization and the powder yield was increased up to about 50%. With further optimization of the process parameters and usage of improved flow breakers, the purity and yield of the product powder can be further improved. Since an application in the hardmetal section is not realistic at the moment, applications in the catalysis sector could be considered due to the small grain size and good catalytic activity of the cubic WC1−x phase.
      PubDate: 2022-03-10
       
  • Measurement of the electronic structure of a type-II topological Dirac
           semimetal candidate VAl3 using angle-resolved photoelectron spectroscopy

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      Abstract: Abstract Type-II topological Dirac semimetals are topological quantum materials hosting Lorentz-symmetry breaking type-II Dirac fermions, which are tilted Dirac cones with various exotic physical properties, such as anisotropic chiral anomalies and novel quantum oscillations. Until now, only limited material systems have been confirmed by theory and experiments with the type-II Dirac fermions. Here, we investigated the electronic structure of a new type-II Dirac semimetal VAl3 with angle-resolved photoelectron spectroscopy. The measured band dispersions are consistent with the theoretical prediction, which suggests the Dirac points are located close to (at about 100 meV above) the Fermi level. Our work demonstrates a new type-II Dirac semimetal candidate system with different Dirac node configurations and application potentials.
      PubDate: 2022-03-03
      DOI: 10.1007/s42864-022-00141-w
       
  • Strengthening of tungsten by coherent rhenium precipitates formed during
           low fluence irradiation

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      Abstract: Abstract Experimental data show that the accumulation of rhenium and osmium from transmutation reactions severely affect the microstructural evolution and property degradation of tungsten-based materials under neutron irradiation. Theory and modeling have confirmed that Re atom transport in W is by irradiation-produced migrating self-interstitial atoms. With this diffusion mode in operation, a specific microstructure evolution is realized when at relatively low neutron fluence the Re-rich precipitates are formed, while the void and interstitial loop population development is suppressed, affecting the mechanical properties. This research shows the effect of small coherent Re-rich precipitates on the dislocation glide under stress, investigated using the molecular dynamics approach with empirical interatomic potentials. The results are compared with an earlier simulation of void hardening in W. It is demonstrated that small coherent Re-rich precipitates of less than 6 nm diameter represent relatively weak obstacles for moving edge dislocations. The implication of these results on the interpretation of experimental results is discussed.
      PubDate: 2022-03-01
      DOI: 10.1007/s42864-021-00088-4
       
  • Preparation of the highly dense ceramic–metal fuel particle with
           fine-grained tungsten layer by chemical vapor deposition for the
           application in nuclear thermal propulsion

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      Abstract: Abstract The cermet fuel element was achieved by dispersing the UO2 particles with or without tungsten (W) coating layer uniformly in the W matrix. It is considered to be a robust and secure fuel for use in nuclear thermal propulsion in the near future. In this study, the effect of deposition temperature on the densification and grain refinement of the W coating layer was investigated. A high-density (19.24 g·cm−3) W layer with a uniform thickness (~ 10 μm) and fine grains (~ 297 nm) was prepared by spouted-bed chemical vapor deposition. The prepared high-density, fine-grained W layer has the following advantages. It can prevent direct contact between fuel particles, resulting in a more uniform fuel distribution. In addition, it can decrease the reaction probability between the fuel kernel and H2, and prevent the release of fission products from the fuel kernel by extending the diffusion path at grain boundaries more efficiently. Moreover, the high-density, fine-grained W layer showed outstanding thermal and mechanical performance. Its average hardness and Young’s modulus were approximately 7 and 200 GPa, respectively. The thermal conductivity of the W film was 101–124 W·m−1·K−1 at 298–773 K. This work furthers our understanding of the potential application of the high-density, fine-grained W layer in nuclear thermal propulsion.
      PubDate: 2022-03-01
      DOI: 10.1007/s42864-021-00117-2
       
  • Preface to the special issue on Polyoxometalates

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      PubDate: 2022-01-25
      DOI: 10.1007/s42864-022-00137-6
       
  • Recent advances in polyoxoniobate-catalyzed reactions

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      Abstract: Abstract The search for polyoxometalate-based catalysts has long attracted interest. Being designable in structure, stable and effective, polyoxoniobate-based catalysts have an exciting prospect for industrial applications. This paper not only summarizes recent advances in classic polyoxoniobate-catalyzed reactions, including chemical warfare agents and organic dyes degradation, epoxidation reactions, photocatalytic hydrogen evolution and base-catalyzed reactions but also discusses some representative cases and the speculative mechanism related to structures. In addition, the current challenges and perspectives in the fabrication of more efficient and promising polyoxoniobate-based catalysts are also presented.
      PubDate: 2022-01-25
      DOI: 10.1007/s42864-021-00134-1
       
  • Hydrogen bond-mediated polyoxometalate-based metal-organic networks for
           efficient and selective oxidation of aryl alkenes to aldehydes

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      Abstract: Abstract Selective oxidation of aryl alkenes to aldehydes is an important approach to produce industrial raw materials, in which the exploration of an efficient heterogeneous catalyst is significant but challenging. In this work, three hydrogen bond-mediated polyoxometalate(POM)-contained metal–organic networks with the formulas of [Ni(BTD)2(H2O)2]2[SiW12O40]·12H2O (1), [Ni(BTD)2(H2O)]2[SiW12O40]·6H2O (2) and [Zn(BTD)2(H2O)]2[SiW12O40]·6H2O (3) (BTD = 4H,4ʹH-[3,3ʹ-bi(1,2,4-triazole)]-5,5ʹ-diamine) were hydrothermally synthesized, in which the metal–organic fragments interact with POM clusters via abundant hydrogen bonding to extend the structure into three-dimensional supramolecular networks. To be explored as heterogenous catalysts, compounds 1–3 showed high catalytic activity and selectivity for the selective oxidation of styrene to benzaldehyde. Among them, compound 1 exhibits the highest performance with ca. 99% styrene conversion and ca. 99% selectivity of benzaldehyde in 5 h. Moreover, compound 1 displays rich substrate compatibility, recyclability and good structural stability. A series of experiments demonstrated that the high performance of compound 1 should be attributed to the synergistic effect among polyoxoanion and coordination-unsaturated metal centers in metal–organic fragments, which facilitates the activation of H2O2 and styrene substrates, thus enhancing the catalytic performance.
      PubDate: 2022-01-18
      DOI: 10.1007/s42864-021-00130-5
       
  • Preparation of tungsten–iron composite oxides and application in
           environmental catalysis for volatile organic compounds degradation

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      Abstract: Abstract Emission of volatile organic compounds has important influence on complex air pollution and human health. In this paper, a series of tungsten–iron composite oxides with different proportions and preparation methods were synthesized and first used for catalytic combustion of chlorobenzene and toluene, as typical polluting gas sources. These WO3-based solid catalytic materials were systematically characterized by modern analytical methods, and the results showed that there was strong electron interaction between W and Fe elements in the composite oxides, and the presence of a certain amount of tungsten oxide inhibited the crystallization of iron oxide, and vice versa, which were beneficial to the uniform dispersion of tungsten–iron components into each other and the improvement of redox properties. Compared with single-component oxide, the formation of tungsten–iron composite oxide affected the micro-structure, improved the specific surface area and optimized the pore structure of materials. The performance test results showed that the tungsten–iron composite oxide (FeWO4–0.5Fe2O3, molar ratio of tungsten and iron was 1/2) prepared using citric acid-based sol–gel method was the optimal, and its catalytic degradation efficiency could reach 90% for chlorobenzene and 83% for toluene at 320 °C, and maintain at least 60 h without obvious deactivation, with high selectivity to the formation of HCl and CO2.
      PubDate: 2021-12-17
      DOI: 10.1007/s42864-021-00128-z
       
 
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