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Many applications involving plasma–liquid interactions depend on the reactive processes occurring at the plasma–liquid interface. We report on a falling liquid film plasma reactor allowing for in situ optical absorption measurements of the time-dependence of the ferricyanide/ferrocyanide redox reactivity, complemented with ex situ measurement of the decomposition of formate. We found excellent agreement between the measured decomposition percentages and the diffusion-limited decomposition of formate by interfacial plasma-enabled reactions, except at high pH in thin liquid films, indicating the involvement of previously unexplored plasma-induced liquid phase chemistry enabled by long-lived reactive species. We also determined that high pH facilitates a reduction-favoring environment in ferricyanide/ferrocyanide redox solutions. In situ conversion measurements of a 1:1 ferricyanide/ferrocyanide redox mixture exceed the measured ex situ conversion and show that conversion of a 1:1 ferricyanide/ferrocyanide mixture is strongly dependent on film thickness. We identified three dominant processes: reduction faster than ms time scales for film thicknesses >100 µm, •OH-driven oxidation on time scales of <10 ms, and reduction on 15 ms time scales for film thickness <100 µm. We attribute the slow reduction and larger formate decomposition at high pH to HO 2 − formed from plasma-produced H2O2 enabled by the high pH at the plasma–liquid interface as confirmed experimentally and by computed reaction rates of HO 2 − with ferricyanide. Overall, this work demonstrates the utility of liquid film reactors in enabling the discovery of new plasma-interfacial chemistry and the utility of atmospheric plasmas for electrodeless electrochemistry. [ABSTRACT FROM AUTHOR]

Diosmetin (Dio) has attracted much attention because of its good pharmacological effects, thus it is necessary to determine its content in scientific research and production. In the study, stable orange‐red copper nanoclusters with 4‐hydroxy‐2‐mercapto‐6‐propylpyrimidine (PTU) as reducing agent and ligand (PTU‐CuNCs) was prepared by a simple approach with superior quantum yield (18.03 %), and the PTU‐CuNCs with red fluorescence could improve the anti‐interference ability of detection. Meanwhile, the synthesis conditions of PTU‐CuNCs were optimized and analyzed in detail. Through a series of experiments, it was found that inner filter effect (IFE) and dynamic quenching might become the main reasons for the fluorescence quenching of PTU‐CuNCs by Dio. Based on the mechanism, a fluorescence probe for the determination of Dio was established. In the range of 0.33–31.67 μmol L−1, the fluorescence quenching efficiency of PTU‐CuNCs was linearly related to the contents of Dio, and corresponding limit of determination (LOD) was estimated to be 101.3 nmol L−1, and limit of quantitation (LOQ) was calculated to be 337.4 nmol L−1. Furthermore, the method could be used effectively for the assay of Dio in practical samples. [ABSTRACT FROM AUTHOR]

N,N-diethylhydroxylamine (DEHA) is a new salt-free reducing agent applied in the separation of Pu from U in the reprocessing of irradiated fuel from nuclear power plants. The effect of monomethylhydrazine (MMH) on the γ-rays radiolysis of DEHA-HNO3 solution is presented in this paper. MMH can effectively enhance DEHA stability against radiation, and the main radiolytic products are H2, CH4, CH3CHO, CH3COOH and HNO2. The content of H2, CH4, CH3CHO and CH3COOH is raised with the dose. The amount of H2, CH4 and CH3CHO enhances with the MMH concentration, but CH3COOH concentration is reduced when MMH concentration is raised. [ABSTRACT FROM AUTHOR]

The one-step direct laser writing process has been an efficient strategy for constructing flexible metal structures. However, the effect of laser wavelength on the structuring process remains unclear, thus restricting the universal manufacturing process development. In this work, the feasibility of one-step writing of flexible Cu structures with different wavelength continuous diode lasers has been verified. Here, photothermal reactions dominate in the decomposition of the reducing agent to form copper structures. Differences in the wavelength primarily affect the photothermal reaction amplitude for structuring, resulting in a variation in the formation of Cu structures. Under our processing conditions, the photothermal reaction induced by 532 nm laser is higher than 808 nm laser, a higher reduced-joining degree of the Cu structure can be achieved by 532 nm laser. This results in a superior conductivity, adhesion, and bendability of Cu structures fabricated by 532 nm laser than that of 808 nm laser. Furthermore, strain sensors that can detect different bending angles and bending frequencies have been fabricated by 532 nm laser-written structures to demonstrate their practical applications. [ABSTRACT FROM AUTHOR]

The formation of inclusion bodies (IBs) in microbial cell factories is a very common process occurring during recombinant protein production. Different protocols have been developed for the extraction of soluble proteins from IBs using several strategies, ranging from the use of harsh denaturing and high concentrations of chaotropic agents and reducing agents to the use of mild protocols based on the use of non-denaturing detergents. However, in recent years, the biological vision of IBs has changed and research studies have demonstrated that these protein aggregates contain biologically active and properly folded recombinant proteins. This drives us to redefine the methodologies currently used to obtain soluble protein using IB as a protein source. Hence, we propose the extraction of IB protein via the simple spontaneous solubilization of IB as a strategy broadly applicable to all kinds of recombinant proteins without the negative effects of detergents and chaotropic agents on final biological activity. We prove the wide applicability of spontaneous solubilization processes to different types of IBs and that protocols can be easily customized for each protein in terms of timing and incubation temperature by monitoring the protein activity of the solubilized fraction. [ABSTRACT FROM AUTHOR]

Herein, we disclosed a protocol for the deoxygenation of allyl arylsulfones to access the corresponding thioethers under photoredox conditions by a "cut-sew" strategy. The key to the success of the deoxygenation process is using triarylphosphines not only as the terminal reductants, but also as the reaction initiators. Deeper understanding of this deoxygenation process enabled the intermolecular deoxygenative allylation. [ABSTRACT FROM AUTHOR]

This review summarizes the progress in the research on polyoxometalate (POM)-decorated gold (Au) and silver (Ag) core–shell structures (Au/Ag@POMs), emphasizing their substantial application potential in catalysis, medicine, and biology. It outlines the central strategies for fabricating Au/Ag@POMs with diverse morphologies and dimensions, leveraging POMs as protective ligands and reducing agents as well as for ligand exchange. Of particular note is the focus on the analysis of the nanoparticle size, shape, and intricate architecture of POM shells using cryo-electron microscopy techniques. By integrating recent findings on atomically precise POM-stabilized nanoclusters, this review delves deeper into understanding surface interface structures, intrinsic atomic architectures, and electronic interactions between POM shells and metallic cores. Collectively, advancements in this field underscore significant strides in the controllable synthesis and precise structural manipulation of Au/Ag@POM architectures, thus paving the way for engineering high-performance metal catalysts. [ABSTRACT FROM AUTHOR]

This study investigates the effects of reducing agents on the structural, morphological, and electrochemical properties of ZnO- and Ni-doped ZnO nanocrystals, which were synthesized via the chemical precipitation method without any capping agent. The morphological and compositional analyses were conducted using field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX). The results suggested that the reducing agent influenced the particle size and morphology, and 6–7 at% Ni was found in the doped ZnO nanocrystals. Crystallographic characterization was performed using X-ray diffraction (XRD), where the crystallinity of the samples was slightly influenced by Ni doping, and wurtzite hexagonal polycrystalline nanocrystals with average crystal sizes between 17 and 25 nm, where the average crystal size increases with Ni doping. Moreover, Raman spectra analyses showed that all samples have the characteristic Raman modes of the ZnO, and the asymmetry ratio analyses of the E2 (high) mode decreased for the Ni-doped ZnO compared to pristine ZnO for both reducing agents. The electrochemical behavior of the ZnO- and Ni-doped ZnO samples was examined through cyclic voltammetry, and the nanocrystals synthesized via NaOH solution had a higher current density. The results showed that using different reducing agents and doping with Ni significantly impacted the morphological, structural, and electrochemical properties of the ZnO-based nanocrystals. [ABSTRACT FROM AUTHOR]

Introduction: This review article gives an overview of the biogenic synthesis of metal nanoparticles (mNPs) while using Litchi chinensis extract as a reducing and stabilizing agent. The subtropical fruit tree i.e lychee contains phytochemicals such as flavonoids, terpenoids, and polyphenolic compounds which act as reducing agents and convert the metal ions into metal atoms that coagulate to form mNPs. Methodology: Different methodologies adopted for the synthesis of lychee extract and its use in the fabrication of mNPs under different reaction conditions such as solvent, extract amount, temperature, and pH of the medium have also been discussed critically in detail. Techniques: Different techniques such as FTIR, UV–visible, XRD, SEM, EDX, and TEM adopted for the analysis of biogenic synthesis of mNPs have also been discussed in detail. Applications of mNPs: Applications of these prepared mNPs in various fields due to their antimicrobial, antiinflammatory, anticancer, and catalytic activities have also been described in detail. [ABSTRACT FROM AUTHOR]

Glistening is the condensation of water that forms within the intraocular lens (IOL) materials. In this study, a new approach was attempted to reduce the glistening using various types and content of crosslinking agents. Hydrophobic acrylic IOL materials were prepared from 2-phenoxyethyl acrylate using three different crosslinking agents: ethylene glycol dimethacrylate (EGDMA), 1,4-butanediol diacrylate (BDDA), and glycerol 1,3-diglycerolate diacrylate (GDGDA). The IOL material cross-linked with the GDGDA showed the least amount of glistening. However, the IOL materials exhibited the largest amount of glistening when cross-linked with the EGDMA, indicating that the glistening decreased in the order of GDGDA > BDDA > EGDMA. [ABSTRACT FROM AUTHOR]

Biologically produced silver nanoparticles are becoming a more appealing option than chemically produced antioxidants and antimicrobial agents, because they are safer, easier to manufacture and have medicinal properties at lower concentrations. In this work, we employed the aqueous pomegranate peel extract (PPE) to synthesize silver nanoparticles (PPE-AgNPs), as peel extract is a rich source of phytochemicals which functions as reducing agent for the synthesis of PPE-AgNPs. Additionally, the PPE was examined quantitatively for total phenolics and total flavonoids content. PPE-AgNPs were characterized using analytical techniques including UV–Vis spectroscopy, DLS, FTIR, XRD, HRTEM and FESEM, evaluated in vitro against the plant pathogenic microbes and also for antioxidant activities. Analytical techniques (HRTEM and FESEM) confirmed the spherical shape and XRD technique revealed the crystalline nature of synthesized PPE-AgNPs. Quantitative analysis revealed the presence of total phenolics (269.93 ± 1.01 mg GAE/g) and total flavonoids (119.70 ± 0.83 mg CE/g). Biosynthesized PPE-AgNPs exhibited significant antibacterial activity against Klebsiella aerogenes and Xanthomonas axonopodis, antifungal activity against Colletotrichum graminicola and Colletotrichum gloesporioides at 50 µg/mL concentration. The antioxidant potential of biosynthesized PPE-AgNPs was analysed via ABTS (IC50 4.25 µg/mL), DPPH (IC50 5.22 µg/mL), total antioxidant (86.68 g AAE/mL at 10 µg/mL) and FRAP (1.93 mM Fe(II)/mL at 10 µg/mL) assays. Cytotoxicity of PPE-AgNPs was valuated using MTT assay and cell viability of 83.32% was determined at 100 µg/mL concentration. These investigations suggest that synthesized PPE-AgNPs might prove useful for agricultural and medicinal purposes in the future. [ABSTRACT FROM AUTHOR]

Colloidal InSb quantum dots (QDs) are a potential alternative to toxic Pb‐ and Hg‐chalcogenide QDs for covering the technologically important near‐infrared/shortwave infrared (NIR/SWIR) spectral range. However, appropriate Sb precursors are scarce and obtaining narrow size distributions is challenging. Tris(dimethylamido)antimony (Sb(NMe2)3) is an appealing choice due to its commercial availability and non‐pyrophoric character but implies the reduction of antimony from the +3 to the required –3 state. In reported works, strong reducing agents such as lithium triethylborohydride are used, which lead to the fast co‐reduction of both Sb3+ and In3+. The downsides of this approach are reproducibility issues and the risk of forming metal nanoparticles due to the different reduction kinetics of Sb3+ and In3+. Here, indium(I) halides are explored as simultaneous indium source and mild reducing agent for the antimony precursor. The wavelength of the excitonic absorption peak of the phase‐pure InSb QDs obtained with this approach can be tuned from 630 to 1890 nm, which corresponds to a size range of ≈2–7 nm. The synthesis can also be conducted in a heat‐up manner, which facilitates the scale‐up and paves the way for the use of InSb QDs in applications such as NIR/SWIR photodetectors, cameras, biological imaging, and telecommunications. [ABSTRACT FROM AUTHOR]

This study investigates the direct carbonylation of glycerol using a composite photocatalyst (TiO2 loaded with cellulose) and 2-cyanopyridine as a waterreducing agent. In this research, the performance of the photocatalytic system was evaluated under different conditions, including various concentrations of 2-cyanopyridine, glycerol, and catalyst dosage, as well as changing the molar ratios of CO2 to glycerol and reaction times. The optimal conditions for achieving high glycerol conversion and GlyCO3 performance were determined, resulting in a glycerol conversion of 92.43% and a yield of 91.12% towards glycerol carbonate under these conditions. Increasing the concentration of 2-cyanopyridine up to 30 mmol enhanced GlyCO3 production. However, excessive amounts led to decreased yields due to catalyst site blockage. The influence of the CO2 to glycerol molar ratio on GlyCO3 yield was marginal within a certain concentration range, indicating a non-limiting CO2 supply. Catalyst loading significantly affected product yield, with higher concentrations promoting greater GlyCO3 formation. However, catalyst reusability tests revealed a decline in activity after recycling, attributed to drying-induced deactivation. These findings provide valuable insights into optimizing the cellulose-TiO2 photocatalyst for efficient glycerol carbonylation, contributing to the advancement of sustainable chemical processes. [ABSTRACT FROM AUTHOR]

The energetic characteristics of a novel ionic cocrystal composed of 1H-tetrazole/sodium perchlorate and differences of properties between the cocrystal and simple mixture are reported herein. Cocrystals containing reductants and oxidizers exhibit enhanced energy release rate compared with their simple mixture owing to their short molecular distances. Differential scanning calorimetry, thermogravimetric analysis, sensitivity tests and humidity tests are performed to clarify the properties of the cocrystals and simple mixture. The calculated detonation velocity of the cocrystal was higher than that of 1H-tetrazole. The cocrystal achieves high deflagration performance, as evaluated via a pressure vessel test. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Agricultural Sciences / Jurnal Ilmu Pertanian Indonesia is the property of IPB University 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.)

The complex environmental conditions at Cr-contaminated sites, characterized by uneven ion distribution, oxidants competition, and limited solid-phase mobility, lead to inadequate mixing of Fe-based reducing agents with Cr, posing significant challenges to the effectiveness of Cr remediation through Cr-spinel precipitation. This study investigates the distinct roles of Fe(II), Fe(III), and Cr(III) in Cr-spinel crystallization under ambient temperature and pressure. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray absorption near-edge structure spectroscopy, and Mössbauer spectroscopy were employed to elucidate the phase composition, microstructure, and ion coordination within the precipitates. Our findings indicate that Fe(II) acts as a catalyst in the formation of the spinel phase, occupying octahedral sites within the spinel structure. Under the catalytic influence of Fe(II), Fe(III) transitions into the spinel phase, occupying both the tetrahedral and the remaining octahedral sites. Meanwhile, Cr(III), due to its high octahedral site preference energy, preferentially occupies the octahedral sites. When Fe(II) or Fe(III) is present but does not meet the ideal stoichiometric ratio, a deficiency in Fe(II) leads to low yield and poor crystallinity of Cr-spinel, whereas a deficiency in Fe(III) can completely inhibit its formation. Conversely, when either Fe(II) or Fe(III) is in excess, the formation of Cr-spinel remains feasible. Furthermore, metastable Cr phases can be transformed into stable Cr-spinel by adjusting the Fe(II)/Fe(III)/Cr(III) ratio. These results highlight the broad range of conditions under which Cr-spinel mineralization can occur in environmental settings, enhancing our understanding of the mechanisms driving Cr-spinel formation in Cr-contaminated sites treated with Fe-based reducing agents. This research provides critical insights for optimizing Cr remediation strategies. [ABSTRACT FROM AUTHOR]

The [PdCl2(Xantphos)] complex, in comparison with several [PdCl2(P–P)] complexes having different diphosphine chelating ligands (P–P), is very active as a catalyst for the carbonylation of iodobenzene to methyl benzoate. The run conditions and the influence of several cocatalysts have been also studied to further improve the catalytic activity. The optimization of the catalytic system allowed to obtain TOFs of ca. 260,000 h−1. The addition of some additives able to reduce the possible catalyst deactivation allowed to increase the TOF of ca. 15%. The best positive results were obtained by adding reducing agents such as ferrocene, which leads to a TOF higher than 300,000 h−1. [ABSTRACT FROM AUTHOR]

An oxidase (OXD) -like AuAg@AuNPs nanozyme was prepared by Au seeds growth using dopamine carbon dots as reducing and capping agents. The AuAg@AuNPs show excellent OXD-like and surface-enhanced Raman spectroscopy (SERS) activities and can oxidize the non-Raman-active leucomalachite green (LMG) into the Raman-active malachite green (MG). The research displays that D-penicillamine (D-PA) can effectively inhibit the OXD-like activity of Au@AgNPs and enhance the SERS signals as substrate. It is attributed to the formation of S–Au bond due to thiol (-SH) in D-PA. Therefore, a highly sensitive and specific SERS dual-readout sensing platform was proposed to assay D-PA with a limit of detection of 0.1 μg/mL (direct SERS mode) and 6.64 μg/L (indirect SERS mode). This approach was successfully used to determine D-PA in actual pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

Principal‐agent theorizing is based on the idea of a linear inverse relationship between principal control and agency slack: the higher the control over the agent, the less likely is the agent to slack. In this paper, we challenge this assumption by explicitly taking the varying nature of agents into account. While control may reduce the agent's room for maneuver, it does not explain the extent to which different agents are inclined to put efforts in circumventing these obstacles. Focusing on international organizations (IOs), we measure member states' as principals' control over IO administrations as their agents as well as the latter's intrinsic propensity to slack across eight major IOs. The analysis shows that low control by the principal is not necessarily associated with run‐away agents, whereas high control is not necessarily associated with servant‐like agents. The assumed control–slack relationship can thus be distorted and determining an ideal level of control is not possible without considering the agent's entrepreneurialism. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office 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.)

Phenylhydroxylamine and its derivates (PHAs) are important chemical intermediates. Phenylhydroxylamines are mainly produced via the catalytic reduction of aromatic nitro compounds. However, this catalytic reduction method prefers to generate thermodynamically stable aromatic amine. Thus, designing suitable catalytic systems, especially catalysts to selectively convert aromatic nitro compounds to PHAs, has received increasing attention but remains challenging. In this review, we initially provide a brief overview of the various strategies employed for the synthesis of PHAs, focusing on reducing aromatic nitro compounds. Subsequently, an in-depth analysis is presented on the catalytic reduction process, encompassing discussions on catalysts, reductants, hydrogen sources, and a comprehensive assessment of the merits and drawbacks of various catalytic systems. Furthermore, a concise overview is provided regarding the progress made in comprehending the mechanisms involved in this process of catalytic reduction of aromatic nitro compounds. Finally, the main challenges and prospects in PHAs' production via catalytic reduction are outlined. [ABSTRACT FROM AUTHOR]

Single-domain antibodies, including variable domains of the heavy chains of heavy chain-only antibodies (VHHs) from camelids and variable domains of immunoglobulin new antigen receptors (VNARs) from cartilaginous fish, show the therapeutic potential of targeting antigens in a cytosol reducing environment. A large proportion of single-domain antibodies contain non-canonical cysteines and corresponding non-canonical disulfide bonds situated on the protein surface, rendering them vulnerable to environmental factors. Research on non-canonical disulfide bonds has been limited, with a focus solely on VHHs and utilizing only cysteine mutations rather than the reducing agent treatment. In this study, we examined an anti-lysozyme VNAR and an anti-BC2-tag VHH, including their non-canonical disulfide bond reduced counterparts and non-canonical cysteine mutants. Both the affinity and stability of the VNARs and VHHs decreased in the non-canonical cysteine mutants, whereas the reduced-state samples exhibited decreased thermal stability, with their affinity remaining almost unchanged regardless of the presence of reducing agents. Molecular dynamics simulations suggested that the decrease in affinity of the mutants resulted from increased flexibility of the CDRs, the disappearance of non-canonical cysteine–antigen interactions, and the perturbation of other antigen-interacting residues caused by mutations. These findings highlight the significance of non-canonical cysteines for the affinity of single-domain antibodies and demonstrate that the mutation of non-canonical cysteines is not equivalent to the disruption of non-canonical disulfide bonds with a reducing agent when assessing the function of non-canonical disulfide bonds. [ABSTRACT FROM AUTHOR]

In the present study, pyroligneous acid, also known as wood vinegar, has been employed as reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs) anchored on nanocellulose (NC). The idea is to confer the latter bactericidal properties for its typical uses such as in cosmetics and food-packing. It has been demonstrated that AgNPs can be directly produced onto NC in one-pot fashion while dramatically enhancing the kinetics of AgNPs synthesis (2 h for reaction completion) in comparison to the NC-less counterpart (10 days for reaction completion). Furthermore, NC allowed for a narrower size distribution of AgNPs. NC-supported and non-supported AgNPs had sizes of 5.1 ± 1.6 nm and 16.7 ± 4.62 nm, respectively. Immortalized human keratinocytes (HaCat) cells were then employed as model to evaluate the cytotoxicity of the AgNPs-NC compound. The latter was found not to impact cell proliferation at any formulation, while decreasing the viability by only 6.8% after 72 h. This study contributes to the development of more environmentally benign routes to produce nanomaterials and to the understanding of their impact on cells. [ABSTRACT FROM AUTHOR]

Cyclodextrins (CDs) are macrocycles that are well suited for forming inclusion complexes for surface-enhanced Raman scattering (SERS) detection of analytes due to their low Raman activity, which minimizes background SERS signals and enhances the detection of target molecules without interference. In this paper, we systematically investigated the synthesis of both silver (Ag) and gold (Au) nanoparticles (NPs) using CDs as reducing and capping agents in a basic environment using microwave (MW), ultrasound (US), and room temperature (RT) synthesis. We found that replacing NaOH with K2CO3 as an alkaline environment almost doubles the size (from <10 nm to around 20 nm) of AgNPs in the MW-assisted synthesis. Synthesis using the US produces less stable particles due to the sample evolution after US irradiation. Ag (20 nm) and Au (11 nm) were successfully obtained at room temperature in the presence of CDs and K2CO3. All synthesized particles present SERS activity. CD capping allowed us to detect hydrophobic molecules like naphthalene and melamine. In the case of methylene blue, the CD capping prevents the changes induced in the SERS by a basic pH. We also demonstrate that the newly synthesized NPs can discriminate by SERS the propranolol enantiomers. Moreover, propranolol inclusion in CDs leads to a dramatic change in its SERS spectrum. [ABSTRACT FROM AUTHOR]

An organophotocatalytic method has been described towards the synthesis of indolines and oxindoles starting from unusual α-chloro amide and N-(2-chlorophenyl)-N-alkyl methacrylamide substrates. This marks a notable improvement since the earlier syntheses utilized iridium and gold catalysts, and involved C–I or C–Br bond cleavage as the initial step. Our photocatalyst is a pincer ligand that can be easily deprotonated to make a very strong reducing agent. The reductive cleavage of the carbon–chloride bond, and subsequent 5-exo-trig ring cyclization, followed by hydrogen atom abstraction, prepare the desired heterocycles under very mild reaction conditions. An atom economic use of KOtBu has been shown to demonstrate the unusual trifunctional role of the latter. [ABSTRACT FROM AUTHOR]

The recovery of spent lithium‐ion batteries by traditional acid leaching is limited by serious pollution, complicated technology, and the low purity of Li2CO3. To address the problems of the traditional acid leaching process and increasing demand for decarbonization, a technique for the selective carbonation leaching of Li and the recovery of battery‐grade Li2CO3 by a simple concentration precipitation process without acids or bases was developed. The coupling of CO2 and reducing agents could effectively promote the precipitation of MCO3 (M=Ni/Co/Mn) and the selective leaching of Li by decreasing the reducing capability needed for transition metals and decreasing the pH of the solution. The optimal selective leaching process of Li was obtained under 1 MPa CO2 with 20 g/L Na2S2O3 at an L/S ratio of 30 mL/g for 1.5 h. FT‐IR, XRD, ICP‐MS and other methods were used to reveal the multiphase interfacial reaction mechanism of the carbonation reduction of layered cathode materials, which indicated that the reducing agent Na2S2O3 could promote lattice distortion of the cathode materials and effective separation of Li. In summary, a green and economical method for the selective recovery of battery‐grade Li2CO3 using a one‐step method of CO2 carbonation recovery in a near‐neutral environment was proposed. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) is an important platinum group metal for the manufacture of advanced materials owing to its chemical and physical properties. Generally, it is extremely difficult to dissolve Ru metal by using acidic solutions containing strong oxidizing agents. Therefore, pretreatments like alkali fusion roasting at high temperature are practiced to render the Ru metal soluble in aqueous solution. In this work, a simple procedure was proposed to dissolve Ru metal at room temperature without any pretreatments. The dissolution procedure consisted of two steps: (i) oxidation of Ru metal to RuO4– by using pure NaClO solution; (ii) reduction of RuO4– to stable Ru2OCl104– by using HCl as a reducing agent. The role of NaClO and HCl in the dissolution of Ru metal was discussed on the basis of the potential-pH diagram and the corresponding oxidation and reduction reactions. The effect of several parameters like the concentration of NaClO and HCl, temperature, time, and pulp density was investigated. Optimum conditions were obtained to completely dissolve Ru metal by using NaClO and HCl solution without alkali fusion. [ABSTRACT FROM AUTHOR]

High-efficiency reduction of Fe3O4 particles in molten copper slag is the key for recovering slag-entrained copper, although restrained by the sluggish reaction kinetics of commercial powdery reductants with low density. Here, a new strategy by density tuning in conjunction with pelletizing of the powdery reductants is suggested, greatly enhancing the Fe3O4 reduction kinetics and resulting in remarkably facilitating the recovery of slag-entrained copper. Specifically, by replacing the industrially used coal powder with FeS2-C pellets at optimized density, the efficiency of Fe3O4 reduction is significantly increased from 18% to 51%, with the copper content in the low-layer slag being correspondingly enriched from 1.37% to 4.53%. The SEM-EDS characterizations and finite element analytical results all reveal that the enhanced reduction of Fe3O4 by the as-designed reductant contributes to the decrease of slag viscosity and copper exposure, as well as to the size growth of copper matte droplets, resulting in promoted settling of copper-containing components for copper–slag separation in the molten state. Additionally, the full exposure and size growth of copper matte in the molten state facilitate copper reclamation during the subsequent grinding–flotation process of the solidified slag, which increases the copper recovery from 23.3% to 85.3%, with the concentrate grade being correspondingly improved from 2.8% to 6.45% after one-stage flotation. The results can provide new insights into enhancing the recovery of slag-entrained copper. [ABSTRACT FROM AUTHOR]

The authors of this study focused on the energy and material assessment of processes for processing pellets from metal-bearing waste, specifically Fe concentrate. A mathematical model was created for process evaluation, with which thermotechnical calculations of parameters in the processing of metallized pellets were carried out. Thermodynamic calculations were performed to determine the enthalpy of the charge in individual devices (drying chamber, rotary kiln, cooler). For the reduction of Fe oxides, carbon from coke (with Fe oxide reductions of 50%, 61%, and 92%) and lignite (with Fe oxide reductions of 69% and 92%) were considered as part of the pellets. The degree of reduction of iron oxides was a determining parameter, and the consumption of the reducing agent corresponded to the direct reduction of Fe oxides by carbon with a coefficient of 1.5. Another determining parameter was the input and output temperature in individual devices. For a more precise description of the processes in individual devices, calculations were carried out zonally. The results of the calculations are analyses and recommendations for feasible alternatives for the reducing agent and associated processes. [ABSTRACT FROM AUTHOR]

Copyright of Chemkon - Chemie Konkret is the property of Wiley-Blackwell 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.)

The present study aims to evaluate the use of cranberry bush fruit pomace (CBFP) (Viburnum opulus L.), which has recently become popular raw material, as a substrate in the presence of a reducing agent to increase biobutanol production by Clostridium beijerinckii DSMZ 6422. For this purpose, some factors were optimized, including the pretreatment, initial concentration of CBFP (5–20%), different types of reducing agents (ascorbic acid, L-cysteine, sodium dithionite and sodium sulfite), different concentrations of sodium dithionite (2.5–15 mM), inoculum concentration (5%, 10%, and 20%), and fermentation time (24–96 h). The maximum biobutanol, total ABE, biobutanol yield, and biobutanol productivity were 9.45 g/L, 12.08 g/L, 0.21 g/g, and 0.13 g/L/h in the medium containing enzymatically hydrolyzed 10% CBFP, 10 mM sodium dithionite, and 20% inoculum at the end of 72 h, respectively. These findings demonstrate that CBFP can be considered as a sustainable, economical, and viable substrate on biobutanol production for the first time in the literature. [ABSTRACT FROM AUTHOR]

Citrus juices are rich sources of antioxidants, including vitamin C, but are prone to oxidation during storage. We investigated the application of gallic acid (GA), an environmentally friendly reducing agent, as active packaging to mitigate this issue. Orange juice was packaged in airtight glass containers both with and without GA‐based oxygen scavenger (GA‐OS) label and stored at 20°C and 4°C. During the storage, we monitored oxygen levels in the headspace and dissolved oxygen concentration in the orange juice, vitamin C content and browning. In the presence of GA‐OS, oxygen levels in the headspace were reduced by half in under 1 h at 21°C and within 2 h at 4°C. Dissolved oxygen concentration decreased 50% after 8 h at 21°C and after 1.2 days at 4°C. In the absence of GA‐OS, vitamin C degraded completely within 30 days at 21°C and 45 days at 4°C. In contrast, GA‐OS nearly fully preserved vitamin C for 105 days at both temperatures. Browning, quantified by delta E, escalated in GA‐OS‐absent samples to 16.79 ± 0.16 at 21°C to 12.19 ± 0.10 at 4°C, whereas GA‐OS samples exhibited no significant browning. Our results underscore GA‐OS's efficacy in preserving the quality of liquid foodstuffs, exemplified by orange juice, suggesting its broad range applicability as active packaging. [ABSTRACT FROM AUTHOR]

The effect of different chemical pre-desulfurization processes were compared to achieve the utilization of high sulfur coal efficiently and economically and its total sulfur content is 2.19%. The major influence factors were the reagent dosage, desulfurization temperature, and time. Compared with single-factor experiments, orthogonal experiments can greatly reduce the number of experiments and ensure the rationality of experimental data. The desulfurization rate of acid leach, alkali leach, oxidation, and catalytic reduction were 41.67%, 17.16%, 26.96%, and 27.45%, respectively, and the total sulfur after the pre-desulfurization process were 1.19%, 1.69%, 1.49%, and 1.48%, respectively. Range analysis and variance analysis were employed for the crucial operational parameters. In acid and alkali leaching desulfurization process, the acid/alkali concentration had the greatest influence on the desulfurization effect. In oxidation desulfurization process, the desulfurization time had the greatest influence on the desulfurization effect. In catalytic reduction desulfurization, the reducing agent dosage was the most important factor. The main factor for the results above was that the desulfurization mechanisms were different. Therefore, the research of different desulfurization mechanisms is the main direction of future work. The consequence of this paper would provide data support for the selection of the desulfurization method for high sulfur coal. [ABSTRACT FROM AUTHOR]

To eliminate the harm of nitrogen oxides to human health and ecological environment, selective catalytic denitrification using methane as a reducing agent (CH4-SCR) has received widespread attention. Developing highly active CH4-SCR denitrification catalysts has become a research focus of this technology. In this article, Co(x)/ZRP catalysts were prepared by impregnation method, and the effects of Co(x)/ZRP catalysts with different cobalt loading amounts on the denitrification performance of CH4-SCR were investigated. The physicochemical properties of Co (x)/ZRP catalysts were characterized using XRD, H2-TPR, Py-IR, NH3-TPD and NO-TPD methods. The CH4-SCR denitrification performance of Co(x)/ZRP catalysts was evaluated on fixed bed micro-reactor under atmospheric pressure. The results showed that the cobalt species in the Co(x)/ZRP catalyst were Co3O4. With the increase of cobalt loading, the Co3O4 grains became larger, the redox ability and NO adsorption and desorption performance of the catalyst were improved. With the increase of cobalt loading, the denitrification activity of Co(x)/ZRP catalyst first increased and then decreased, which was consistent with the variation of medium strong acid amount in the total acid of the catalyst. Among them, the Co(20)/ZRP catalyst had a higher amount of medium strong acid, and the CH4-SCR denitrification performance was good, with Tm of 342 °C, XNomax of 39.2%. The L-acid and medium strong acid content of the catalyst played an important role in the CH4-SCR catalytic denitrification activity of the catalyst. [ABSTRACT FROM AUTHOR]

Nanoparticles have unique characteristics with applications in different fields of industry and medicine. There are several methods for synthesizing zinc oxide nanoparticles, mostly according economic and environmental criteria. On this contribution, it is presented a review on zinc oxide nanoparticles synthesized by "green route" methods and their biomedical advantages such as anticancer and antibacterial properties. To obtain this type of environment-friendly nanoparticles with different morphologies, zinc salts are used as precursor and as reductants. Plants as biological media are used as well, that is because naturally occurs within their systems reduction processes and/or phytochemical extracts of some part of plants. Thankfully to these green routes, the exposure and final disposal of toxic substances that involve conventional chemical methods are mitigated. [ABSTRACT FROM AUTHOR]

Enormous advances have been made in the synthesis of metal nanoparticles (NPs) affording a high degree of control over their size, shape, and composition. In recent years, a growing effort has been dedicated to incorporating principles of green chemistry in different aspects of NPs, ranging from reagents/solvents to their fate in the environment. In this report, we focus on the use of Cyrene (dihydrolevoglucosenone) as an alternative green solvent for the synthesis of metal NPs. We begin with the synthesis of Ag NPs, given their prominence in the literature. Through control reactions, we show that Cyrene has a dual role of solvent and reducing agent. Additionally, the conversion yield for the Ag NPs synthesis was studied with respect to temperature and the Ag precursor. We then expand on the synthetic methodology to access Pd, Pt, and Bi NPs. The functionality of the synthesized NPs is assessed by employing them as electrocatalysts for furfural reduction and the hydrogen evolution reaction. We envision the use of Cyrene as a green solvent can be extended toward the synthesis of NPs of other metals and classes of materials. [ABSTRACT FROM AUTHOR]

To reduce the manufacturing cost of polymer electrolyte membrane fuel cells (PEMFCs), tests targeting the decrease of reaction temperature and the amount of reducing agent in the polyol method for the synthesis of Pt/C catalysts were conducted. The reaction temperature in the polyol method was changed from 50 to 160 °C. Through XRD and TGA, it was determined that the reduction of platinum ions by the oxidation of ethylene glycol started at 70 °C. Below a 60 °C reaction temperature, Pt (1 1 1) peaks in XRD were barely visible, indicating that no deposition occurred. TEM revealed that Pt particles were well-dispersed above a 100 °C reaction temperature. For manufacturing platinum catalysts using the polyol method, it was found that 100 °C is the optimal synthesis temperature. Additionally, it was found that similar performance can be achieved by adding water to decrease the amount of ethylene glycol during synthesis. Finally, considering various analyses, it is evident that the dispersion, size, and crystallinity of platinum particles had the most significant impact on performance. [ABSTRACT FROM AUTHOR]

Development of heavy gas oil (HGO) desulphurisation (DS) through altering the composition of employed catalysts is crucial to enhance the quality of clean fuels production. Therefore, this research work reports an effective low-cost desulphurization performance for HGO fraction using unsupported nickel particles, of mixed compositions, having morphologies as nanotube and nanoflower-like as novel catalysts. The introduced structures were synthesised by electroless deposition technique using two reducing agents. The various characteristics of these catalysts were confirmed by XRD, TEM, BET and TGA analysis. The results of gas oil desulfurization revealed that the use of different reducing agents during the preparation stage could have an effect on the level of sulfur removal. Particularly, the produced catalyst by using methylamine, as a reducing agent, could have stronger affinity towards DS process compared to that of the obtained catalyst by hydrazine. Specifically, the catalyst of the superior DS activity could exhibit 97.5% sulfur removal from a heavy gas oil feedstock contains 10,000 ppm as sulfur content. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, a method for the enantioselective reduction of unprotected 2‐alkylpyridines is reported for the first time. By using pinacolborane and an amide as reducing agents, a large number of 2‐alkylpiperidines were synthesized with high yields and excellent enantioselectivities via a cascade process involving 1,4‐hydroboration and subsequent transfer hydrogenation. The resulting products can be easily converted to natural alkaloids. [ABSTRACT FROM AUTHOR]

The present research conducted two experiments with an intelligent tutoring system to investigate the overall and dynamic impact of emotional support from a pedagogical agent (PA). In Experiment 1, a single factor intergroup design was used to explore the impact of PA's emotional support (supportive vs. non-supportive) on learners' emotions, intrinsic motivation, and learning gain. Sixty participants were recruited and randomly assigned to one of the two conditions. Experiment 2 also conducted a single factor between-subjects design to investigated the dynamic patterns between emotions and learning strategies among 30 participants using lag sequential analysis. Results showed that: Compared with the non-supportive pedagogical agent, the supportive pedagogical agent reduced frustration and improved learning gain, but did not increase intrinsic motivation. In addition, learners with the supportive pedagogical agent used more appropriate strategies after frustration and surprise, and use less ineffective strategies after confusion and enjoyment to avoid reaching a wrong answer. If learners did not receive emotional support in such cases, learning strategies following these emotions were more likely lead to negative cognitive results, or negative emotions tended to appear repeatedly. Instructors or PAs should identify learners' emotions in time and provide the appropriate emotional support according to learners' emotions. [ABSTRACT FROM AUTHOR]

This study investigates the effects of gallium doping on the structural, optical, and electrochemical properties of FeO–MgO nanoparticles synthesized using a greener approach by utilizing the plant extract of Citrus nobilis. The phytochemical studies of Citrus nobilis performed by GC–MS showed the presence of different reducing agents present in it. The synthesized nanoparticles were characterized by FTIR, SEM, XRD, and UV–Visible techniques. XRD results showed the size of prepared gallium-doped FeO–MgO nanoparticles is about 2.6nm. UV–Vis studies showed a band gap of 2.7 eV for FeO–MgO and 2.1 eV for Ga (FeO–MgO). A slight difference of 0.6 eV in the band gap highlights the influence of gallium on electronic transitions in FeO–MgO nanoparticles. Linear sweep voltammetry (LSV) analysis of Ga (FeO–MgO) showed a contrasting effect with undoped FeO–MgO nanoparticles. The results showed the FeO–MgO nanoparticles as highly conductive materials, while Ga (FeO–MgO) showcasing a controlled conductance profile signifies its potential applications in electronics and photovoltaics where controlled conductance is required. [ABSTRACT FROM AUTHOR]

The characteristics of water treated with cavitation-assisted electric discharge plasma have been studied. In the discharge itself, hydroxyl radicals and hydrogen and oxygen atoms are generated. With the cyclic passage of water through the discharge area, secondary products are formed that have oxidizing, reducing, and slightly alkaline properties. The yield of oxidizing and reducing agents was measured depending on the dose (total energy) deposited in the discharge. The results obtained give reason to assume that during the cyclic treatment of water with the cavitation-assisted discharge, octaoxidane H2O8 is formed in the liquid. The H2O8 concentration at a dose of 240 J/10 mL is ~10−3 mol/L. [ABSTRACT FROM AUTHOR]

The field of 2D nanomaterials is ever-growing with a myriad of synthetic advancements that have been used to obtain such materials. There are top-down, as well as bottom-up, fabrication methods for obtaining 2D nanomaterials; however, synthesis of 2D nanomaterials from solution offers a simple scalable way to control size, shape, and surface. This review outlines the recent advances in colloidal polyol synthesis of 2D nanomaterials and provides perspectives on the similarities and differences in various syntheses. Various materials classes are presented and discussed, including metals, oxides, chalcogenides, and halides, that can be synthesized as 2D nanomaterials via a polyol process. Throughout the literature, polyol media is demonstrated to be versatile not only as a solvent and reducing agent for metal precursors but also as a binding and shape-directing agent for many 2D nanomaterials. Polyols also offer the ability to dissolve various surfactants and additives that can further control the morphology and composition of various nanomaterials. In this review, we outline the various 2D materials that have been realized via the solution polyol route. [ABSTRACT FROM AUTHOR]

Olefination of aldehydes is one of the fundamental reactions in organic synthesis. The commonly used Wittig olefination reaction however uses stoichiometric quantities reagents under basic conditions resulting in stoichiometric amounts of byproducts. Known catalytic alternate to the Wittig reaction requires stoichiometric amounts of silane reducing agents and high temperature. Herein, we report a base‐free olefination of aryl aldehydes using propiolates as a surrogate for the Witting reagent under silver catalysis. Trimethyl orthoformate, in the presence of a silver catalyst adds to the alkynoate to form the nucleophilic silver allenolate which reacts with the reactive oxocarbenium ion formed from aldehyde under the reaction conditions. Subsequently, decarbonylation occurs to form the olefin. Trans olefin is formed exclusively from simple aryl aldehydes and cinnamaldehydes. Such a silver allenolate is conceptually novel and has not been explored so far. [ABSTRACT FROM AUTHOR]

The concurrent activation and surface modification (CAM) process is an integrated process used to synthesise palm kernel shell derived activated carbon (PKSdAC) in this study. CAM involves chemical activation and surface modification via metal impregnation in one process. This study investigated the usage of different acids as chemical activators and different soaking procedures for impregnating barium (Ba) in CAM-PKSdAC. It shows that chemical impregnation of PKS using 10% sulphuric acid (H2SO4) mass loading via two soaking steps can impregnate a high Ba amount of 0.86–2.98 wt. % in CAM-PKSdAC, compared to one soaking step. The two soaking steps procedure reduced the overage formation of BaSO4 from sealing the pores of PKS. Comparing HCl and H2SO4, at 30% acid mass loading, the impregnation of PKS with H2SO4 produced a higher impregnated Ba amount in CAM-PKSdAC. BaSO4 generated from the reaction between H2SO4 on the PKS surface with BaCl2 solution causes a reduction reaction at high temperatures. BaSO4 reacted with a carbon-reducing agent and is reduced to barium sulphide (BaS), impregnating Ba on CAM-PKSdAC. In conclusion, H2SO4 was found to be the suitable chemical activator with two soaking steps for the CAM process. [ABSTRACT FROM AUTHOR]

A new series of [CoIII–CF3]n+ complexes supported by a bidentate redox-active ligand is presented. The cationic [Co–CF3]+ complex was first obtained by reacting [CpCo(tBuUreaopda)] (Cp = cyclopentadienyl, opda = o-phenylenediamide) with an electrophilic trifluoromethyl source, for which the redox-active phenylenediamide ligand serves as a 2e− reservoir to generate [CpCp(tBuUreabqdi)(CF3)]+ (bqdi = benzoquinonediimine). Electrochemical studies of [Co–CF3]+ revealed two reversible 1e− reductions. Chemical reduction with 1 or 2 equiv. reducing agent enabled isolation of the neutral and anionic complexes, respectively, where the [CoIII–CF3] bond remains intact in all three oxidation states (n = +1, 0, −1). Structural analysis shows systematic changes to the redox-active ligand backbone upon reduction, consistent with sequential ligand-centered electron transfer in the series [bqdi]0 to [s-bqdi]˙− to [opda]2−. In contrast, the reaction of [CpCo(tBuUreaopda)] with alkyl triflates resulted in ligand-centered alkylation at the ureayl groups instead of the targeted Co–alkyl bond formation, suggesting less favorable bond formation at cobalt and greater nucleophilic accessibility of the ligand compared to the metal center. [ABSTRACT FROM AUTHOR]

The solvothermal method of producing spherically shaped and highly fluorescent tiny (∼3 nm) nitrogen-doped carbon quantum dots (NCQDs) with high quantum yield (43%) from Ixora coccinea flowers and o-phenylenediamine has been approached sustainably. Since these NCQDs exhibit excitation-dependent fluorescence activity, they were used to detect the Fe3+ ion selectively in real-time in human blood serum, because it is a component of human blood. The limit of detection (LOD) of the NCQDs was found to be 60 nM. We also synthesized palladium nanoparticles utilizing the NCQDs without additional reducing or stabilizing agents because these quantum dots serve as both. Numerous characterization techniques were used to characterize the nanoparticles, and all the characterizations showed the presence of NCQDs, which stabilize the nanoparticles. Palladium nanoparticles' small size (4 nm) and large surface area (35.77 m2 g−1) enable them to exhibit strong catalytic activity in Suzuki–Miyaura coupling and cyanation processes. It is obvious that synthetic palladium nanoparticles and NCQDs have a variety of uses in the fields of catalysis and sensing respectively. [ABSTRACT FROM AUTHOR]

Nanoparticle green synthesis is an emerging scientific field that focuses on the production of nanoparticles by living cells. In this work, the potential of extracts of alfalfa leaves (Medicago sativa) as affordable and fabricated zirconium nanoparticles (ZrNPs) was evaluated for the first time. alfalfa alcoholic extract and zirconium precursor were used to produce ZrNPs, the production and characteristics of nanoparticles were measured using the Tyndall effect, UV‐vis, FT‐IR, EDX, DLS, and SEM tests, antioxidant and antibacterial properties, and toxicity Measurement of nanoparticles on breast cancer (MDA‐MB‐468) and human healthy cells (HFF) was investigated. The optimization of nanoparticle production was evaluated with ANN and GN algorithms. The analysis showed that nanoparticles have spherical‐like ZrNPs shapes with an average of 50 nm size. in addition, ZrNPs have significant cytotoxic effects against human breast cancer (MDA‐MB‐468) cells, and Human foreskin fibroblast (HFF) cells exhibited the highest resistance to ZrNPs. There was a significant agreement between the results of the designed ANN‐GA model and the experimental data. In this research, ZrNP was successfully created using alfalfa extract as a renewable source of stabilizing and reducing agents with an environmentally friendly approach, and they showed significant antioxidant, antibacterial, and anticancer properties. [ABSTRACT FROM AUTHOR]

Fluorinated arylborane‐based Lewis acid catalysts have shown remarkable activity and serve as ideal examples of transition metal‐free catalysts for diverse organic transformations. However, their homogeneous nature poses challenges in terms of recyclability and separation from reaction mixtures. This work presents an efficient technique for the heterogenization of boron Lewis acid catalysts by anchoring Piers' borane to allyl‐functionalized iron oxide. This catalyst demonstrates excellent activity in the hydrosilylation of imines and the reductive amination of carbonyls using various silanes as reducing agents under mild reaction conditions. The catalyst exhibits broad tolerance towards a wide range of functional substrates. Furthermore, it exhibits good recyclability and can be easily separated from the products using an external magnetic field. This work represents a significant advance in the development of sustainable heterogenous metal‐free catalysts for organic transformations. [ABSTRACT FROM AUTHOR]

This concept addresses the main economic, environmental, scientific and technological issues associated with the use of homogeneous Pt‐catalysts in the important industrial hydrosilylation process. The development of biphase catalysis is proposed as the most promising approach. One solution we suggest is the use of ethylene glycol (EG) as a medium in biphase catalysis. We have previously shown that EG in Pt‐catalyzed hydrosilylation serves not only as a medium but also as a mild reducing agent of Pt‐ions to Pt0, as well as an effective ligand for the preparation of mononuclear Pt01‐complexes. These zero valent platinum complexes are single‐atom catalysts (SAC) and have high activity in hydrosilylation, stability during storage and the ability to be recycled multiple times (~40 times). This option of using an atomic catalyst allows us to combine the advantages of homogeneous and heterogeneous catalysts. [ABSTRACT FROM AUTHOR]