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ABSTRACT Three novel complexes of copper(II), ruthenium(III), and thorium(IV) ions with quinaldine azo dye ligand HL were synthesized in nanoscale. Applying mass spectroscopy, electronic, infrared, 1H NMR, elemental, and thermal investigations, their structures were examined. By using azo nitrogen and hydroxyl oxygen atoms to coordinate as a monobasic bidentate, it was found that the ligand displayed bicapped square antiprism geometry with thorium(IV) metal ion, square pyramidal arrangement in copper(II) complex and octahedral configuration in ruthenium(III) complex. In order to confirm the complexes' geometrical arrangement, theoretical investigations were carried out using DFT/B3LYP/6–311 + G(d,p)/LANLDZ. The dipole moment, geometrical configuration, energetic parameters, and HOMO–LUMO gap of energy have been calculated. The compounds were formed in nanometric forms, as indicated by the mean particle sizes obtained by applying TEM. Based on TEM images for the complexes of copper(II), ruthenium(III), and thorium(IV), their average particle sizes were 11.04, 3.89, and 1.52 nm, respectively. PANC‐1 and A‐549 cells were used in the tests to evaluate the compounds' anticancer activity against the vinblastine reference. The findings confirm the great cytotoxicity effect of the free ligand and its complexes against the investigated cell lines using different doses of the examined compounds. Ru(III) and Cu(II) complexes exhibited cytotoxic effectiveness greater than that of vinblastine. The azo ligand, HL, exhibited the strongest antibacterial activity that is superior to that of the conventional medicines themselves and greater than that of its metal complexes. The most physiologically active compound's ideal conformation was found using molecular docking research, and the manner in which the Ru(III) complex and the enzyme of Panc‐1 link together was determined. It interacts in three different modes with the target receptor (PANC‐1): hydrophobic force, electrostatic force, and H‐bond. In addition to increasing the candidate activity, these interactions can be used to design and predict new, effective compounds. The capacity of the ligand and its complexes to act as heterogeneous catalysts for the oxidation of methyl violet 2B was examined. The ruthenium(III) and thorium(IV) complexes generated the greatest catalytic efficiencies. [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (AgNPs) have been successfully synthesized using leaf extract of Neem (Azadirachta Indica), Mint (Mentha Piperita), Tulsi (Ocimum Tenuiflorum), Bermuda grass (Cynodon Dactylon) and silver salt. As plant extracts produce best capping material for the stabilization of nanoparticles. AgNPs were characterized by UV–Vis spectroscopy in range of 200–800 nm and transmission electron microscopy TEM, XRD and FTIR. The nanoparticles synthesized were mainly in sizes between 25 and 100 nm. They appeared to be spherical, nanotriangles and irregular in shape. Catalytic application was observed for all the aqueous solution of leaves, quantity taken was 1 ml, 2 ml, 3 ml, 4 ml and 5 ml. Furthermore, prepared Ag nanoparticles are also used for seed germination.

Bee products, abundant in bioactive ingredients, have been utilized in both traditional and contemporary medicine. Their antioxidant, antimicrobial, and anti-inflammatory properties make them valuable for food, preservation, and cosmetics applications. Honeybees are a vast reservoir of potentially beneficial products such as honey, bee pollen, bee bread, beeswax, bee venom, and royal jelly. These products are rich in metabolites vital to human health, including proteins, amino acids, peptides, enzymes, sugars, vitamins, polyphenols, flavonoids, and minerals. The advancement of nanotechnology has led to a continuous search for new natural sources that can facilitate the easy, low-cost, and eco-friendly synthesis of nanomaterials. Nanoparticles (NPs) are actively synthesized using honeybee products, which serve dual purposes in preventive and interceptive treatment strategies due to their richness in essential metabolites. This review aims to highlight the potential role of bee products in this line and their applications as catalysts and food preservatives and to point out their anticancer, antibacterial, antifungal, and antioxidant underlying impacts. The research used several online databases, namely Google Scholar, Science Direct, and Sci Finder. The overall findings suggest that these bee-derived substances exhibit remarkable properties, making them promising candidates for the economical and eco-friendly production of NPs. [ABSTRACT FROM AUTHOR]

Rationally controlling the morphology and microstructure of the zeolite crystals could play a significant role in optimizing their physicochemical properties and catalytic performances for application in various zeolite-based heterogeneous catalysis processes. Among different controlling strategies, the utilization of zeolite growth modifiers (ZGMs), which are molecules capable of altering the anisotropic rates of crystal growth, is becoming a promising approach to modulate the morphology and microstructural characteristics of zeolite crystals. In this mini-review, we attempt to provide an organized overview of the recent progress in the usage of several easily available polymer-based growth modifiers in the synthesis of some commonly used microporous zeolites and to reveal their roles in controlling the morphology and various physicochemical properties of zeolite crystals during hydrothermal synthesis processes. This review is expected to provide some guidance for deeply understanding the modulation mechanisms of polymer-based zeolite growth modifiers and for appropriately utilizing such a modulation strategy to achieve precise control of the morphology and microstructure of zeolite crystals that display optimal performance in the target catalytic reactions. [ABSTRACT FROM AUTHOR]

The graphene family and graphite oxide catalysts, particularly graphene oxide structures, have emerged over the past decade as a robust approach for developing common organic reactions and synthesizing heterocyclic compounds under different conditions. This review highlights the potential of using these catalysts for selective organic compounds, particularly N-heterocyclic compounds, which have numerous applications in life and material science. This article also provides an overview of different graphene oxide catalytic structures based on Fe, Cu, Mn, Pd, Ni, Co, Si, and Al for synthesizing N-heterocyclic compounds. Catalyst attributes include recyclability, effectiveness, catalyst lifespan, lack of catalyst nanoparticle mass, and the required time for catalyst effects on the reactions. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mg alloys/Mg-based composites are utilized significantly in the construction of missiles, aerospace and automobiles due to their lightweight, specific strength, and hardness. In the recent work, Mg-based two-components (Mg–TiO2/Mg–Al2O3) and three-components (Mg–TiO2–Al2O3) composites were fabricated through solid-phase synthesis (powder metallurgy method). Temperature (30 °C), pressure (760 mm Hg) and concentration factors were optimized prior to experiments. The characterization of obtained composites were performed through different physicochemical methods like Surface analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). FTIR analysis verified the composite fabrication. SEM determined microstructures and particle size of the materials in µm dimensions. XRD confirmed the homogeneity and crystalline nature of the obtained composites. The surface area of the produced samples was observed to vary from 40 to 70 m2/g. These properties allow the prepared composites to play the main role in different adsorption applications and catalytic analysis. The prepared materials were considered to be used as catalyst for the formation of CNTs. The catalytic efficiency was observed to be 80 % for the growth of CNTs. [ABSTRACT FROM AUTHOR]

Bee products, abundant in bioactive ingredients, have been utilized in both traditional and contemporary medicine. Their antioxidant, antimicrobial, and anti-inflammatory properties make them valuable for food, preservation, and cosmetics applications. Honeybees are a vast reservoir of potentially beneficial products such as honey, bee pollen, bee bread, beeswax, bee venom, and royal jelly. These products are rich in metabolites vital to human health, including proteins, amino acids, peptides, enzymes, sugars, vitamins, polyphenols, flavonoids, and minerals. The advancement of nanotechnology has led to a continuous search for new natural sources that can facilitate the easy, low-cost, and eco-friendly synthesis of nanomaterials. Nanoparticles (NPs) are actively synthesized using honeybee products, which serve dual purposes in preventive and interceptive treatment strategies due to their richness in essential metabolites. This review aims to highlight the potential role of bee products in this line and their applications as catalysts and food preservatives and to point out their anticancer, antibacterial, antifungal, and antioxidant underlying impacts. The research used several online databases, namely Google Scholar, Science Direct, and Sci Finder. The overall findings suggest that these bee-derived substances exhibit remarkable properties, making them promising candidates for the economical and eco-friendly production of NPs.

Rationally controlling the morphology and microstructure of the zeolite crystals could play a significant role in optimizing their physicochemical properties and catalytic performances for application in various zeolite-based heterogeneous catalysis processes. Among different controlling strategies, the utilization of zeolite growth modifiers (ZGMs), which are molecules capable of altering the anisotropic rates of crystal growth, is becoming a promising approach to modulate the morphology and microstructural characteristics of zeolite crystals. In this mini-review, we attempt to provide an organized overview of the recent progress in the usage of several easily available polymer-based growth modifiers in the synthesis of some commonly used microporous zeolites and to reveal their roles in controlling the morphology and various physicochemical properties of zeolite crystals during hydrothermal synthesis processes. This review is expected to provide some guidance for deeply understanding the modulation mechanisms of polymer-based zeolite growth modifiers and for appropriately utilizing such a modulation strategy to achieve precise control of the morphology and microstructure of zeolite crystals that display optimal performance in the target catalytic reactions.

Owing to advantages in synthesis, separation, structure determination, and low cost (compared to noble metal nanoclusters), Ag/Cu hydride clusters (and their alloys) have received increasing research interest in recent decades and have shown great potential in mediating reduction reactions and H2 storage applications. The atomic precision of the Ag/Cu hydride clusters with the combination of single-crystal X-ray diffraction, 1/2H nuclear magnetic resonance, electrospray ionization mass spectrometry, density functional theory, and particularly, single-crystal neutron diffraction, has provided pivotal information regarding its structural characteristics, facilitating a deep understanding of the inherent bonding principles therein. This review summarizes the research progress of atomically precise Ag/Cu hydride clusters (and their alloys) over the past three years (2021–2023), mainly focusing on the synthesis, structure analysis, and catalytic applications of the hydride clusters. We believe that this review can benefit the future design of different types of metal hydride clusters and aid in their application in various redox reactions.

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Single-atom catalysts (SACs) with active metals dispersed atomically have shown great potential in heterogeneous catalysis due to the high atomic utilization and superior selectivity/stability. Synthesis of SACs using carbon-neutral biomass and its components as the feedstocks provides a promising strategy to realize the sustainable and cost-effective SACs preparation as well as the valorization of underused biomass resources. Herein, we begin by describing the general background and status quo of carbon-based SACs derived from biomass. A detailed enumeration of the common biomass feedstocks (e.g., lignin, cellulose, chitosan, etc.) for the SACs preparation is then offered. The interactions between metal atoms and biomass-derived carbon carriers are summarized to give general rules on how to stabilize the atomic metal centers and rationalize porous carbon structures. Furthermore, the widespread adoption of catalysts in diverse domains (e.g., chemocatalysis, electrocatalysis and photocatalysis, etc.) is comprehensively introduced. The structure-property relationships and the underlying catalytic mechanisms are also addressed, including the influences of metal sites on the activity and stability, and the impact of the unique structure of single-atom centers modulated by metal/biomass feedstocks interactions on catalytic activity and selectivity. Finally, we end this review with a look into the remaining challenges and future perspectives of biomass-based SACs. We expect to shed some light on the forthcoming research of carbon-based SACs derived from biomass, manifestly stimulating the development in this emerging research area. [Display omitted] • Advances in carbon-based SACs derived from biomass and its components are reviewed. • Unique interactions between metal and biomass for atomic metal dispersion are revealed. • Conformations of active atomic metal on biomass-derived carbon carriers are elaborated. • Applications of biomass-based SACs in diverse catalysis are comprehensively introduced. [ABSTRACT FROM AUTHOR]

Acyltransferases (ATs) are important tailoring enzymes that contribute to the diversity of natural products. They catalyze the transfer of acyl groups to the skeleton, which improves the lipid solubility, stability, and pharmacological activity of natural compounds. In recent years, a number of ATs have been isolated from plants. In this review, we have summarized 141 biochemically characterized ATs during the period July 1997 to October 2020, including their function, heterologous expression systems, and catalytic mechanisms. Their catalytic performance and application potential has been further discussed. [ABSTRACT FROM AUTHOR]

Nanocatalysts are very much efficient than the traditional catalysts because of their large surface to mass ratio, high absorbing ability, simple and high reusability. Copper nanoparticles have been investigated as a new class of heterogeneous nanocatalyst for a diverse range of chemical reactions. In this category, copper iodide nanoparticles (CuI NPs) have received a lot of interest among synthetic chemists due to their valuable advantageous such as high atom economy, inexpensive, simple preparation, readily available and reusability of the catalyst. The present review focuses on the developments in the chemistry of CuI NPs-catalyzed chemical reactions. The review aims to comprehensively discuss relevant work, which was mainly done in the field in recent times. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new family of binuclear ruthenium(III) complexes has been synthesized. • Rhombic distortion of an octahedral geometry around metal is identified. • Facile one-pot aldehyde to amide transformation is investigated. • Present result indicates the excellent conversion of aldehydes to amides. A series of new binuclear ruthenium(III) complexes [ Ru 2 Cl 4 (EPh 3) 4 (L)] (E = P or As) were successfully synthesized from 1:2 mol ratio of bi-nucleating ligand precursors (L 1 H 2 - L 3 H 2) and [RuCl 3 (EPh 3) 3 ] in benzene for 6 h. The complexes were characterized by elemental analysis, FT-IR, UV–vis, magnetic susceptibility measurements and EPR spectroscopy methods. Rhombic distortion (gx ≠ gy ≠ gz) around the ruthenium ion was confirmed by EPR spectra in liquid nitrogen temperature. Catalytic activity of the facile one pot amidation reaction has been developed. The complex [Ru 2 Cl 4 (AsPh 3) 4 (L 1)](4) was found to possess excellent conversion up to 100 % of amide in toluene with the presence of hydroxylamine hydrochloride and NaHCO 3 at 110 °C in 2 h. The effect of time, temperature, solvents and different catalytic loading experiments was also investigated. [ABSTRACT FROM AUTHOR]

Copper has received extensive attention in the field of catalysis due to its rich natural reserves, low cost, and superior catalytic performance. Herein, we reviewed two modification mechanisms of co-catalyst on the coordination environment change of Cu-based catalysts: (1) change the electronic orbitals and geometric structure of Cu without any catalytic functions; (2) act as an additional active site with a certain catalytic function, as well as their catalytic mechanism in major reactions, including the hydrogenation to alcohols, dehydrogenation of alcohols, water gas shift reaction, reduction of nitrogenous compounds, electrocatalysis and others. The influencing mechanisms of different types of auxiliary metals on the structure-activity relationship of Cu-based catalysts in these reactions were especially summarized and discussed. The mechanistic understanding can provide significant guidance for the design and controllable synthesis of novel Cu-based catalysts used in many industrial reactions. [ABSTRACT FROM AUTHOR]

The ordered mesoporous metal oxides as catalytic carrier or active center have been reported by many literatures. The large specific surface area and ordered mesoporous structure had caused great concern in the field of catalysis. In the catalytic reaction, the ordered mesoporous materials had great mechanical properties and the active centers had strong interaction between each other. There were obviously advantages of these ordered mesoporous materials than bulk materials or routine nano-materials in the catalytic conversion of volatile organic compound, CO, NOx and other polluting gases. At present, researchers prepared a variety of ordered mesoporous metal oxides by different synthetic methods. Based on the analysis and summary of the literature, this paper briefly reviewed the preparation methods and application of ordered mesoporous metal oxide catalysts and the prospect of future development is worth expecting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver nanoparticles (AgNPs) were phytosynthesized by the Lallemantia royleana leaf extract. • Physical and chemical characteristics of the synthesized AgNPs were evaluated. • The synthesized AgNPs were spherical and crystalline with average size 34.47 ± 1.6 nm. • The prepared AgNPs demonstrated significant antioxidant and antimicrobial, anti-inflammatory, anti-arthritic, cytotoxic, and catalytic activities. The study of the silver nanoparticles (AgNPs) synthesis based-green methods become more interesting recently due to their low-cost preparation, eco-friendly and non-toxic precursors. The present study approved the ability of the Lallemantia royleana (Benth. in Wall.) Benth. leaf extract for the synthesis of AgNPs for the first time. The synthesized AgNPs were physico-chemical characterized using ultraviolet–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), Fourier Transform-Infrared Spectroscopy (FT-IR), zeta potential and transmission electron microscopy (TEM) analysis. The total phenols, flavonoids, anthocyanin, tannin contents, antioxidant, antimicrobial, anti-inflammatory, anti-arthritic and cytotoxic activities of L. royleana leaf extract and the synthesized AgNPs were investigated. The biocatalytic activity of prepared AgNPs was assessed on methylene blue as a pollutant organic dye. The TEM examination showed that the synthesized AgNPs were predominantly spherical with some mixed shapes and crystalline with average size 34.47 ± 1.6 nm, and showed a localized surface plasmon resonance (LSPR) peak at 425 nm. The zeta potential value was −24.1 mV indicating the stability of produced AgNPs. The new prepared AgNPs have lower total phenols, flavonoids, anthocyanin, tannin contents than L. royleana leaf extract. In addition, the new prepared AgNPs demonstrated the higher DPPH radical scavenging activity (87 %) and the ABTS radical scavenging activity (77 %) at the maximum prepared concentration of 250 μg mL−1 as compared to the L. royleana leaf extract (62 % and 58 %, respectively). The produced AgNPs also exhibited the higher antimicrobial activity against both the Gram-positive (Staphylococcus aureus and Bacillus cereus) and the Gram-negative (Escherichia coli and Shigella flexneri) bacteria and the Candida strains (Candida glabrata and Candida albicans) as compared to the L. royleana leaf extract. The resulting AgNPs indicated a dose-dependent anti-inflammatory effect on human red-blood cell (RBC) membrane stabilization assay and had more activity (72 %) compared to the L. royleana leaf extract (61 %) at 250 µg mL−1. The prepared AgNPs showed promising in vitro anti-arthritic activity evaluated by 73 % compared to 58 % in case of L. royleana leaf extract. The new produced AgNPs showed the higher cytotoxic effect against the human hepatoma (Hep-G2) and the human breast (MCF-7) cancer cells compared to the L. royleana leaf extract with 79.3 % and 77.2 % at 250 µg/mL, respectively. The obtained results revealed also that the green synthesized AgNPs were capable to catalyze MB dye. Therefore, the obtained results provide a promising route of the green synthesis of AgNPs using L. royleana leaf extract with considerable biopharmaceuticals and catalytic applications. [ABSTRACT FROM AUTHOR]

The application of novel methodologies to the synthesis of nanomaterials is still a challenge in many different technological and scientific fields. New efficient and reproducible synthetic methodologies, that produce fewer residues and reduce the cost of raw materials must be developed. In the present work, we have explored the attractive possibility to apply the cheap iron (II) sulphate salt in the reduction process of the K2PtCl4 to produce colloids suspensions. The synthesis took places in water and was assisted by sodium citrate (SC) using polyvinylpyrrolidone (PVP) as a surfactant. The adjustment of this novelty process allows obtaining well-dispersed and sub-20 nm dendrimer-type platinum nanoparticles (Pt D-NPs). The nano-dendrimers produced have been characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), XRD spectroscopy, inductive couple plasma (ICP) analysis, Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis) spectroscopy. Interesting conformational results derived from the size and shape will be discussed. Catalytic application of the Pt D-NPs has been explored in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) in aqueous media at room temperature obtained TOF value of 253 min-1. Finally, our Pt D-NPs were tested as artificial metalloenzyme showing catechol oxidase activity for oxidation of L-DOPA. [ABSTRACT FROM AUTHOR]

Abstract In the present work, phosphatizing and organic double wastewater were reused to synthesize ZnPO molecular sieves with a hydrothermal method. Enhanced application of the samples was carried out through cyclohexane oxidation and Michael addition alkylation reaction. The removal efficiency of Zn, P in phosphatizing wastewater was over 90%. The characterizations like the crystallite phases, surface morphology and porous features were also confirmed. The catalytic efficiencies of ZnPO prepared in double wastewater system had a good catalytic performance in cyclohexane oxidation and Michael addition reactions, which were much higher than that of the catalyst prepared via simulated system. The surface features of catalysts had a close relationship with such results. These outstanding characters were attributed to more active centers formation, which were brought through interaction of Zn, P, and other metal ions in phosphatizing wastewater, as well as the huge surface area caused by the organic materials in organic wastewater. Graphical abstract Image 10504 Highlights • Using phosphatizing and organic wastewater successfully synthesized ZnPO. • The removal efficiency of pollutants in phosphatizing wastewater was pretty good. • ZnPO showed an excellent catalytic activity in cyclohexane oxidation and Michael addition alkylation reaction. • ZnPO had more active centers and large surface area. [ABSTRACT FROM AUTHOR]

Abstract Porous nickel phosphates, denoted as VSB-1 (Versailles-Santa Barbara-1) and VSB-5 (Versailles-Santa Barbara-5), are crystalline metal phosphate microporous molecular sieves with zeolitic properties. These nickel phosphates could be used as functional catalysts and adsorbents due to interesting properties to readily accommodate many transition metal elements in their frameworks besides zeolitic properties as well as the presence of framework nickel (II) ions. In this account, we provide an overview of selected results regarding their catalytic and sorption applications which have been published in the literature. VSB-1 and VSB-5 are similar to zeolites in many aspects and may be suitable for use as adsorbents for the separation of molecular species and as catalysts or catalyst supports. Particularly, these materials possess unique catalytic properties suitable for several reactions that do not require strong acidity. Isomorphous substitution of Ni2+ with divalent or trivalent transition metals in a nickel phosphate structure can generate new redox centers and Brønsted-Lewis acid centers, providing interesting catalytic properties. Based on an understanding of the formation mechanism of nickel phosphate, VSB-5 was used in electrochemical applications and showed unusual surface chemistry of coordinatively unsaturated Ni2+ sites accessible in its pores. [ABSTRACT FROM AUTHOR]

Metal‐nanoparticles (M‐NPs) have been widely applied in catalysis, imaging, sensing and medicine. One particularly active area of this research is the modification of the surface of the nanoparticles to prevent aggregation through the coordination of ligands. N‐Heterocyclic carbenes (NHCs) have emerged as suitable ligands for this purpose due to their affinity to the metals and their strongly electron donating nature. A number of rationally designed NHC‐modified M‐NPs have been developed using strategies based on metal complex decomposition and ligand exchange. Herein, NHC‐stabilized M‐NPs based on a range of transition metals, especially the recent advances, were summarized. The modification of the surface of the nanoparticles to prevent aggregation through the coordination of ligands is a particularly active area. Numbers of rationally designed NHC‐modified M‐NPs have been developed through metal complex decomposition and ligand exchange. This review summarizes the recent advances of NHC‐stabilized M‐NPs based on a range of transition metals. [ABSTRACT FROM AUTHOR]

Two mononuclear zero-dimensional Ni(II) and Zn(II) complexes bearing diethylenetriamine derivative ligand, namely [NiL(CH3COO)2(H2O)] (1) and [ZnL(CH3COO)2] (2) [L = N, N’-bis(2-hydroxybenzyl)diethylenetriamine], were synthesized under reflux conditions. The molecular composition and structure of the complexes were identified by IR, PXRD, elemental analyses, and single crystal X-ray diffraction. Complex 1 belongs to a monoclinic crystal system with the P21/n space group, and Complex 2 belongs to a monoclinic crystal system with the C2/c space group. The Henry reaction of nitromethane with aromatic aldehydes was explored with Complexes 1 and 2 as the catalyst. Results from the catalytic reaction revealed that the complexes displayed excellent catalytic activities under the optimized conditions and that the substrate scope of aromatic aldehydes could be extended to a certain extent. In addition, the possible catalytic mechanism of the Henry reaction was also deduced.

Ultrasmall (<2 nm) ligand-protected metal nanoclusters (NCs) have been an emerging class of functional materials with rich coordination chemistry, finding increasing acceptance in both basic and applied research owing to their atomic precision, well-defined molecular structure, and intriguing molecular-like properties. The presence of ligands on metal NCs is crucial not only for maintaining their atomic precision and well-defined structure, but also for their rich coordination chemistry with noble metals, influencing the synthesis, and physicochemical and catalytic properties of metal NCs. In this review, we discuss the important roles of ligands to metal NCs, taking water-soluble gold nanoclusters (Au NCs) as an example. The review covers the fundamental understandings (and advances) on the roles of ligands to water-soluble Au NCs in the synthesis ( e.g., influencing the size and formation rate, and revealing the growth mechanisms), physicochemical properties ( e.g., geometrical structure, chirality, stability, solubility, and electronic, photoluminescence and biological properties) and catalytic applications ( e.g., accessibility, activity, selectivity, and coordination of catalytic mechanism of quasi-homogeneous catalysts and immobilization of heterogeneous catalysts). The review also highlights some challenging issues on how ligands and ligand engineering could expand the scope of metal NCs in the synthesis, physicochemical properties, and catalytic application. [ABSTRACT FROM AUTHOR]

In this study, CuO nanoparticles supported on the seashell (CuO NPs/seashell) was prepared using Rumex crispus seeds extract as a chelating and capping agent. The prepared nanocomposite was characterised by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and transmission electron microscopy. The particle size of CuO NPs on the seashell sheets was in the range of 8–60 nm. Catalytic ability of CuO NPs/seashell was investigated for the reduction of 4‐nitrophenol (4‐NP) and Congo red (CR). It was observed that catalyst can be easily recovered and reused several times without any significant loss of catalytic efficiency. [ABSTRACT FROM AUTHOR]

The unique electronic configuration and structural properties of ceria make ceria-based nanomaterials such as morphology-dependent ceria nanocrystals, rare earth-doped ceria-zirconia solid solutions and noble metal-ceria nanocomposites effective promoters in three-way catalysts for low-temperature water-gas-shift reaction, preferential oxidation of traces of CO, the treatment of toxic auto-mobile exhaust, etc. The activities of nanoceria catalysts can be determined by their morphologies, oxygen vacancies, interfacial structures and the type of exposed crystal surfaces, as well as the synergistic effect exhibited by nanocomposites. In this review, the state-of-the-art developments in the well-controlled synthesis of ceria-based nanocatalysts and their applications in both environmental and energy fields is summarized. The involved reaction mechanisms are also briefly introduced, and eventually an outlook in the design of novel nanoceria catalysts for valuable energy applications is addressed. [ABSTRACT FROM AUTHOR]

Zeolites have widely been studied because of the better performance as catalysts and supports. However, the zeolites with only micropores have drawbacks in reactivity and selectivity due to limitation of diffusivity. The hollow zeolite fibers (HZF) with hierarchical porosity however can overcome the problem. The HZF can be synthesized by such methods as incorporated substrate removal method, solid-solid transformation method, co-axial electrospinning technology, dry-wet spinning technology, and hollow fiber incorporation method. The unique hierarchical porous structure leads to the great improvement in the diffusion efficiency of reactants. The catalytic zeolite membrane fibers are the most commonly used as they have stronger catalyst stability and higher catalytic selectivity. The HZFs are suitable in catalytic applications such as selective catalysis, CO preferential oxidation, air purification and wastewater treatment. In order that the HZFs can be applied to industrial operations, more research work should be carried out, such as developments of self-assembly pure HZFs, catalytic substrate incorporated HZFs, HZFs with gradient multicomponent zeolites and HZFs with nanoscale diameters. [Display omitted] • Hierarchical hollow zeolite fibers have distinguished diffusion efficiency. • Highly effective catalytic membranes can be prepared by hollow zeolite fibers. • Hollow zeolite fibers catalysts show stronger stability and higher selectivity. • They well perform in catalysis and treatment of gas and wastewater. • Perspectives in terms of their structures and applications are discussed. [ABSTRACT FROM AUTHOR]

HPWO/Cu(BTC) (BTC = 1,3,5-benzenetricarboxylate) as a new catalyst was prepared by the impregnation method and used to synthesize cyclohexanone ethylene ketal as a probe reaction, which has shown its favorable catalytic activity. FT-IR, XRD, SEM, N adsorption-desorption isotherms and TG/DTA were used to characterize its composition, structure, morphology, stability and toleration for thermal in order to further prepare the catalyst with effective performance. Moreover, we have also explored the optimized conditions of carrying out the probe reaction by orthogonal experiments. The optimized conditions were as follows: fixing cyclohexanone consumption was 0.02 mol, n(cyclohexanone): n(ethylene glycol) = 1:1.3, the mass ratio of the catalyst to total reactant was 0.2 %, cyclohexane dosage was 4 mL, and the reaction time was 75 min. The yield of the acetals and ketones could reach 54.9 ~ 83.5 % under the optimum conditions. In addition, HPWO/Cu(BTC) exhibited good reusability and the approaches above may enable rational design of advanced and environmental-friendly MOF-based catalysts. [ABSTRACT FROM AUTHOR]

This is the first comprehensive review of the biological activity of hydrazone-transition metal complexes. Hydrazone complexes gained much attention because of their antifugial, antibacterial anticonvulsant, and analgesic, antiinflammatory, antimalarial, antimicrobial, antituberculosis, anticancer, and antiviral activities. Additionally, some of the hydrazone complexes were used in treatment of iron overload diseases. One application, which reflects the importance of hydrazone complexes, is their use in detection and determination of metals and some organic constituents in pharmaceutical formulations. This review will provide an overview of the biological, analytical and catalytic applications of this category of complexes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hydrothermal growth of ZnO microrods achieved on porous ceramic substrates. [•] Controlled anisotropic crystal growth attained by controlling hexamine decomposition. [•] pH control leads to surface independent growth characteristics. [•] ZnO microrods grown on porous ceramics can be used as a catalyst support materials. [ABSTRACT FROM AUTHOR]

CuBTC (Copper(II) benzene-1,3,5-tricarboxylate) is one of the most well characterized and widely studied metal organic framework (MOF) structures for potential use in industrial applications due to its relatively easy synthesis and excellent textural and physicochemical properties. In this comprehensive review, a different perspective on MOF materials for future sustainability is presented by critically examining the recent works that have considered the synthesis and adsorption/catalytic applications of CuBTC as a model case. [ABSTRACT FROM AUTHOR]

Carbon nanotubes were synthesized by chemical vapor deposition and subsequently purified and oxidized by repeated treatment with nitric acid. After acid treatment the walls of carbon nanotubes became thinner and the surface area increased. The Ni-supported carbon nanotubes prepared by impregnation were applied to the cracking of n- heptane to show an excellent activity. This indicates that the carbon nanotubes can serve as a good catalyst support with high dispersion of metallic components. The optimum Ni loading turned out to be about 5.2 mmol/g. The cracking product was found to contain mainly small hydrocarbons; thus the Ni-supported carbon nanotubes may be applied as a potential catalyst to the cracking of heavy hydrocarbons. [ABSTRACT FROM AUTHOR]

Salient examples of catalytic application of niobium compounds and materials are demonstrated. Niobium oxides, when small amounts are added to known catalysts, markedly enhance catalytic activity and selectivity and prolong catalyst life for various reactions. Moreover, niobium oxides exhibit a pronounced effect as supports of metal or metal oxide catalysts. Hydrated niobium pentoxide (niobic acid, Nb2O5·nH2O) and niobium phosphate which are unusual solid acids show high catalytic activity, selectivity, and stability for acid-catalyzed reactions. Layer compounds containing niobium combined with metal show peculiar photocatalytic activity. These characteristic features of niobium compounds as catalysts and catalyst components are discussed, their potential significance being emphasized. [Copyright &y& Elsevier]

To develop efficient catalysts is one of the major ways to solve the energy and environmental problems. Spinel ferrites, with the general chemical formula of MFe 2 O 4 (where M = Mg2+, Co2+, Ni2+, Zn2+, Fe2+, Mn2+, etc.), have attracted considerable attention in catalytic research. The flexible position and valence variability of metal cations endow spinel ferrites with diverse physicochemical properties, such as abundant surface active sites, high catalytic activity and easy to be modified. Meanwhile, their unique advantages in regenerating and recycling on account of the magnetic performances facilitate their practical application potential. Herein, the conventional as well as green chemistry synthesis of spinel ferrites is reviewed. Most importantly, the critical pathways to improve the catalytic performance are discussed in detail, mainly covering selective doping, site substitution, structure reversal, defect introduction and coupled composites. Furthermore, the catalytic applications of spinel ferrites and their derivative composites are exclusively reviewed, including Fenton-type catalysis, photocatalysis, electrocatalysis and photoelectro-chemical catalysis. In addition, some vital remarks, including toxicity, recovery and reuse, are also covered. Future applications of spinel ferrites are envisioned focusing on environmental and energy issues, which will be pushed by the development of precise synthesis, skilled modification and advanced characterization along with emerging theoretical calculation. [Display omitted] • This review is started off with a short outlook on crystal structure of spinel ferrites and its synthesis methods. • Five strategies for catalytic performance improvement are innovatively proposed. • The catalytic applications of spinel ferrites in environment and energy field are detailed discussed. • Some vital remarks about toxicity are included. [ABSTRACT FROM AUTHOR]

1) Reduction of synthesis time of the Al-SBA-15 support. 2) The Pt/Al-SBA-15 catalyst was prepared by three different synthesis procedures. 3) Catalyst and support characterization by: XRPD, BET, NH3-TPD, SEM, TPR. 4) The Pt/Al-SBA-15 catalyst also presents low selectivity to cracked products. 5) The catalyst presented a 43% selectivity to the 7-methyl-pentadecane isomer. Oil derived products can be used effectively through the use of bifunctional catalysts in hydroconversion (hydroisomerization/hydrocracking) reactions. Therefore, the objective of this work was studying the n-hexadecane hydroisomerization using a bifunctional Pt/Al-SBA-15 catalyst, evaluating conversion and selectivity to mono branched products. The Al-SBA-15 support was synthesized by three different procedures, two described in literature, an innovator. The support was extensively characterized by several techniques. Pt was impregnated by incipient dry impregnation. The catalyst was characterized and activated. It was evaluated against the n-hexadecane isomerization in batch, 800 rpm, 280, 290 and 300 °C, and 55 bar, 0,052 grams of catalyst/ grams of reactant ratio. The conversion obtained was 100% for 30 h of reaction. The selectivity for mono-branched products obtained was 43% for all catalysts, remaining virtually constant with reaction time and temperature. Thus, this thorough work of bifunctional catalysts synthesis, characterization of the mesoporous support and application in hydroisomerization reactions, provides viable alternatives for the use of oil derived products in an efficient method. [Display omitted] [ABSTRACT FROM AUTHOR]

Cu 2 (bdc) 2 (bpy) metal-organic framework (MOF) was prepared by solvothermal method and the structure was characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR). The specific surface area and the pore size distributions was estimated by Brunauer–Emmett–Teller (BET) method and micropore (MP) plot. This metal-organic framework was used as catalyst to improve the thermal decomposition of ammonium perchlorate (AP) and thermal behaviors of the mixed samples containing the catalyst and ammonium perchlorate were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) experiments. The results showed that in the catalyzed samples, the heat released from thermal decomposition of ammonium perchlorate is much higher (more than 3 times in sample containing 4% by weight of the metal-organic framework as catalyst) and thermal decomposition temperature was significantly lower than that of pure AP (about 110 ​°C decrease in sample containing 2% by weight of catalyst). Thermal decomposition temperature range of AP was reduced from 178 ​°C to 105 ​°C and 61 ​°C in the samples containing 4% and 2% by weight of catalyst respectively. The results of kinetic calculations obtained from Kissinger method showed effective catalytic performance of this metal-organic framework by increasing the thermal decomposition rate constant of AP more than 1.8 times at a much lower temperature. Image 1 • Cu 2 (bdc) 2 (bpy) metal-organic framework was prepared solvothermally. • Effect of catalyst on ammonium perchlorate thermal decomposition was investigated. • Released heat increased more than 3 times in the sample with more amount of catalyst. • Decomposition temperature and its range were significantly decreased. • Activation energy, pre-exponential factor and rate constant were calculated. [ABSTRACT FROM AUTHOR]

• Three Cu(II) and Zn(II) complexes as well as two salicylaldehyde-imine ligands were synthesized and characterized. • The compounds were tested as catalyst in the decomposition reaction of H 2 O 2. • The compounds were screened as antibacterial agents against three gram-negative bacteria and three gram-positive bacteria. Three novel copper(II) and zinc(II) complexes based on salicylaldehyde-imine ligands, namely [Cu(HL1)(CH 3 CH 2 OH)]·(CH 3 COO) (1), [Zn 3 (HL1) 2 (CH 3 COO) 4 (2), and [Zn 2 (L2)]·(CH 3 COO) (3) [H 2 L1 = N,N ′-bis(salicylidene)diethylenetriamine and H 3 L2 = 2,2′-(1 E ,1′ E)-(2,2′-(2-(2-hydroxyphenyl)imidazolidine-1,3-diyl)bis(ethane-2,1-diyl))bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)diphenol] have been synthesized. The complexes were characterized by IR, melting point, and elemental analyses, and the crystal structures were further determined by single crystal X-ray diffraction. These three complexes demonstrated excellent catalytic activities in the decomposition reaction of H 2 O 2 , and the decomposition percent of the H 2 O 2 ranged from 89% to 98% under the optimized reaction conditions. Additionally, the compounds were screened as antibacterial agents against three gram-negative bacteria (Escherichia coli , Klebsiella pneumoniae and Pseudomonas aeruginosa) and three gram-positive bacteria (Bacillus subtilis , Staphylococcus aureus and Corynebacterium xerosis). The results showed that complex 2 possessed stronger antibacterial activities than the two ligands and other two complexes. [ABSTRACT FROM AUTHOR]

Two mononuclear zero-dimensional Ni(II) and Zn(II) complexes bearing diethylenetriamine derivative ligand, namely [NiL(CH3COO)2(H2O)] (1) and [ZnL(CH3COO)2] (2) [L = N, N'-bis(2-hydroxybenzyl)diethylenetriamine], were synthesized under reflux conditions. The molecular composition and structure of the complexes were identified by IR, PXRD, elemental analyses, and single crystal X-ray diffraction. Complex 1 belongs to a monoclinic crystal system with the P21/n space group, and Complex 2 belongs to a monoclinic crystal system with the C2/c space group. The Henry reaction of nitromethane with aromatic aldehydes was explored with Complexes 1 and 2 as the catalyst. Results from the catalytic reaction revealed that the complexes displayed excellent catalytic activities under the optimized conditions and that the substrate scope of aromatic aldehydes could be extended to a certain extent. In addition, the possible catalytic mechanism of the Henry reaction was also deduced. [ABSTRACT FROM AUTHOR]