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In this paper, the in situ TaC/Ni composites were prepared by reactive sintering method using Ta, Ni and graphite as raw materials, and their oxidation behavior at 873, 973 and 1073 K in air is investigated by static cyclic oxidation method. The results present that the oxidation behavior of composites conforms to the linear kinetic law. At 873 K, the oxidation of TaC and Ni–Ta matrix generate NiO, Ta2O5, TaO2 and NiTa2O6. The oxide scale is consisted by double continuous layers, including the outer NiO and inner Ta2O5 layer, due to the diffusion of Ni ion through the oxide ion vacancies in Ta2O5. The Oxygen inward diffuse along the interface between TaC and Ni–Ta matrix, and then dissolves in TaC and replaces C sites to generate Ta oxides. At 973 K, more Ta oxides occupy the oxide scale, forming the alternative distribution of NiO and Ta oxides, resulted from the accelerated diffusion of Ta ions. At 1073 K, the oxide scale is mainly taken up by NiTa2O6 with slight NiO. The formation reaction of Ta2O5 and NiTa2O6 shows high Pilling Bedworth ratio near to 2, resulting in the expansion and compressive stress in oxide scale. The oxidation of composites is primarily controlled by the inward diffusion of Oxygen, leading the formation of non-protective oxide scale with pores and cracks on surface. One effective method to improve the oxidation resistance of TaC/Ni composites is to restrict the formation of Ta2O5 and NiTa2O6, to inhibit the appearance of cracks in oxide scale. [ABSTRACT FROM AUTHOR]

Layered MAX phases possess distinctive chemical, physical, electrical, and mechanical properties due to their amalgamation of metallic and ceramic characteristics. Understanding the corrosion mechanisms of MAX phases in various extreme environments is crucial. This paper commenced by scrutinizing synthesis techniques for MAX phase powders, thin films, and bulk materials, with a focus on fabrication processes and formation mechanisms. Subsequently, it delved into corrosion & oxidation mechanisms in diverse environments, emphasized their unique self-healing properties, and outlined future research directions. This comprehensive and systematic review aims to furnish researchers with effective guidance for selecting MAX phases based on different application environments. [ABSTRACT FROM AUTHOR]

The preparation of gel foams with high stability for inhibiting coal spontaneous combustion remains a huge challenge. In this paper, a highly stable gel foam (SCTH) was developed by introducing nano-hydroxyapatite (HAP) into gel foam system (sodium alginate/calcium L-lactate/tannic acid/composite forming agent). The effects of HAP on the foam performances of SCTH were analyzed. The results showed that HAP could improve the stability of SCTH by forming hydrogen bonds, metal ion bonds with the system and interfacial barriers. After 100 days, SCTH without HAP had only 44.8% of the foam volume remaining. The SCTH with 1.2 wt% HAP had 80% of the volume remaining. In addition, the SCTH had better safety. Thermogravimetric analysis showed that the SCTH could improve the maximum weight loss rate temperature, and increase the residual weight of the coal after thermal decomposition. The coal temperature-programmed oxidation experiment showed that the SCTH could increase the temperature of coal entering the rapid oxidation stage from 120 to 190°C, and the CO inhibition rate was 85.3% at 200°C. Fire suppression experiment showed that the SCTH could reduce the temperature of burning coal by 81.9% within 10 min, thus achieving rapid fire suppression. X-ray photoelectron spectroscopy analysis showed that the SCTH could more effectively reduce the total content of C=O and -COO in coal and block the chain cycle reaction of coal. This work presents a new design idea for using multifunctional nanoparticles to prepare highly stable gel foams with excellent inhibition performance of coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

Exploring effective transition metal single-atom catalysts for selective oxidation of benzene to phenol is still a great challenge due to the lack of a comprehensive mechanism and mechanism-driven approach. Here, robust 4N-coordinated transition metal single atom catalysts embedded within graphene (TM1-N4/C) are systematically screened by density functional theory and microkinetic modeling approach to assess their selectivity and activity in benzene oxidation reaction. Our findings indicate that the single metal atom triggers the dissociation of H2O2 to form an active oxygen species (O*). The lone-electronic pair character of O* activates the benzene C-H bond by constructing C-O bond with C atom of benzene, promoting the formation of phenol products. In addition, after benzene captures O* to form phenol, the positively charged bare single metal atom activates the phenol O-H bond by electron interaction with the O atom in the phenol, inducing the generation of benzoquinone by-products. The activation process of O-H bond is accompanied by H atom falling onto the carrier. On this basis, it can be inferred that adsorption energy of the C atom on the O* atom (EC) and the H atom on the TM1-N4/C (EH), which respectively represent activation ability of benzene C-H bond and phenol O-H bond, could be labeled as descriptors describing catalytic activity and selectivity. Moreover, based on the as-obtained volcano map, appropriate EC (−8 to −7 eV) and weakened EH (−1.5 to 0 eV) contribute to the optimization of catalytic performance for benzene oxidation to phenol. This study offers profound opinions on the rational design of metal single-atom catalysts that exhibit favorable catalytic behaviors in hydrocarbon oxidation. [ABSTRACT FROM AUTHOR]

Bismuth(III) alkanethiolates [Bi(SR)3] formed by reacting Bi2O3 with alkanethiols (RSH) undergo a UV-blue light driven ligand-to-metal charge transfer photoreduction to disulfides and Bi colloids, which are then oxidised to Bi2O3 by dissolved oxygen and reconverted to Bi(SR)3 by RSH to prepare for the next Bi–Bi2O3 photoredox cycle, forming a basis for Bi(III)-catalysed thiol-to-disulfide conversion. [ABSTRACT FROM AUTHOR]

The dearomatizations of non‐activated arenes, particularly those under mild reaction conditions, are highly desired transformations in organic synthesis due to their power in converting flat aromatic rings into three‐dimensional frameworks. Although hypervalent iodine (HVI)‐mediated dearomatization of phenol derivatives has developed rapidly, HVI‐mediated dearomatization of non‐activated arenes remains an urgent and challenging task. To fulfil this task, in this work, we established an HVI‐mediated oxidative dearomatization of non‐activated arenes by using biphenylureas and N‐ or O‐nucleophiles as reactants. This electrophilic dearomatization (DEAr) process is highly regioselective, which enabled different N‐ and O‐nucleophiles to react at the distal C4‐position of the phenyl ring, thus generating dearomative spiro‐products in a single step under mild conditions with wide substrate scope (43 examples, 22%–76% yield). This approach not only provides a successful example for dearomatization of non‐activated arenes under mild reaction conditions, but also has overcome the challenges in HVI‐mediated dearomatization of non‐activated arenes, which will enrich the chemistry of dearomatization. [ABSTRACT FROM AUTHOR]

The dearomatization of aromatic substrates via photocatalytic methodologies has gained escalating prominence to access molecular complexity. Although much focus has been put on non‐active arenes, naphthols and N‐based heteroaromatics, arylamines have so far remained in the background. Herein, we report a photocatalytic strategy for the aerobic, dearomative hydroxylation of naphthylamines under visible‐light irradiation. Our investigation highlights singlet oxygen generation as a viable mechanism for aromaticity disruption, mitigating selectivity issues deriving from the direct oxidation of targeted arylamines. Finally, we showcased the synthetic value of the obtained dearomatized products in a late‐stage diversification campaign. [ABSTRACT FROM AUTHOR]

This study aimed to develop microcapsules with wheat gluten–coated oil droplets to enhance the oxidation stability and control the digestibility of flaxseed oil. The microcapsules were fabricated using a three‐step procedure: (i) flaxseed oil was homogenized with an alkaline gluten solution to form oil‐in‐water emulsions containing small gluten‐coated oil droplets (320–400 nm); (ii) the pH of these emulsions was then neutralized to facilitate the deposition of gluten around the oil droplets, thereby forming a thick layer; (iii) a flaxseed oil microcapsule powder was then prepared by spray drying. During the microcapsule formation, intermolecular interactions, including hydrophobic interactions and hydrogen bonds, were involved in the coacervation of gluten at the emulsion surface. The resultant microcapsules with a multiple‐core structure had external diameters of 4–26 µm and encapsulation efficiencies of 90%–94%. The microencapsulated oil powders contained a relatively high flaxseed oil content (60%–80%). Among them, the sample with 60% oil content demonstrated the best stability in resisting oil droplet coalescence; thus, it exhibited a higher lipolysis rate and extent during simulated gastrointestinal digestion. A 30‐day accelerated storage study showed that encapsulation of the flaxseed oil improved its resistance to oxidation. These findings suggest that the pH‐deposition method can successfully produce microencapsulated polyunsaturated lipids using all plant‐derived ingredients, which may facilitate their use in new plant‐based foods through a green and sustainable approach. [ABSTRACT FROM AUTHOR]

We present new insights into the study of the UO2+x/U4O9 equilibrium in UO2 as a function of the hyper-stoichiometry (x) by coupling HERFD-XANES at the uranium M4-edge with micro-Raman spectroscopy mapping. XANES allowed the measurement of uranium speciation in the samples, while Raman spectroscopy was used to individually characterize the composition and localization of the different oxide phases. UO2 pellets were oxidized under dry conditions at temperatures above the UO2+x/U4O9 phase transition to reach hyper-stoichiometries in the range of 0.01 = x = 0.1. Combining both techniques, we could determine the proportions of U4O9 and UO2+x. We show that at a low O/U ratio, U4O9 is present as small clusters inside UO2 grains. As the O/U increases, we found evidence of the formation of a network of U4O9 crystallized inside the UO2+x grains. The variation of the UO2+x phase hyperstoichiometry (x) was evaluated as a function of the sample oxidation. [ABSTRACT FROM AUTHOR]

It is still a challenge to construct single‐atom level reduction and oxidation sites in single‐component photocatalyst by manipulating coordination configuration for photocatalytic water splitting. Herein, the atomically dispersed asymmetric configuration of six‐coordinated Co‐S2O4 (two exposed S atoms, two OH groups, and two Co─O─Zn bonds) suspending on ZnIn2S4 nanosheets verified by combining experimental analysis with theoretical calculation, is applied into photocatalytic water splitting. The Co‐S2O4 site immobilized by Vs acts as oxidation sites to guide electrons transferring to neighboring independent S atom, achieving efficient separation of reduction and oxidation sites. It is worth mentioning that stabilized Co‐S2O4 configuration show dynamic structure evolution to highly active Co‐S1O4 configuration (one exposed S atom, one OH group, and three Co─O─Zn bonds) in reaction, which lowers energy barrier of transition state for H2O activization. Ultimately, the optimized photocatalyst exhibits excellent photocatalytic activity for water splitting (H2: 80.13 µmol g−1 h−1, O2: 37.81 µmol g−1 h−1) and outstanding stability than that of multicomponent photocatalysts due to dynamic and reversible evolution between stable Co‐S2O4 configuration and active Co‐S1O4 configuration. This work demonstrates new cognitions on immobilized strategy through vacancy inducing, manipulating coordination configuration, and dynamic evolution mechanism of single‐atom level catalytic site in photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

This Minireview examines a selection of case studies that showcase distinctive and enabling electrochemical approaches that have allowed for the generation and reaction of carbocation intermediates under mild conditions. Particular emphasis is placed on the progress that has been made in this area of organic synthesis and polymer chemistry over the past decade. [ABSTRACT FROM AUTHOR]

Dialkyl carbonates (DACs) own an environmentally friendly synthesis route, making them potential candidates as alternative fuels. However, for DACs to be widely accepted as an alternative fuel, a comprehensive understanding of their combustion behavior is essential. Dipropyl carbonate (DPrC) represents a transition from short‐chain to mid‐chain carbonates, understanding its combustion behaviors holds significance in unraveling the combustion chemistry of carbonates. In this study, the oxidation of DPrC was investigated with the initial fuel mole fraction of 0.5% at three equivalence ratios of 0.5, 1.0, and 2.0 within a temperature range of 550–1100 K in a jet‐stirred reactor for the first time. Gas chromatography was utilized for the quantitative detection of reactants, intermediates, and products. A detailed DPrC mechanism was first developed, and good agreements between measurements and simulations were obtained. A notable negative temperature coefficient (NTC) behavior was first observed in the oxidation of DACs. Such NTC phenomenon occurred at fuel‐lean conditions in the temperature range of 620–660 K, while only a weak low‐temperature consumption was observed at the stoichiometric condition. Kinetic modeling studies showed that this unique low‐temperature chemistry of DPrC can be attributed to the differences in the RO2 isomerization reactions between DPrC and short‐chain DACs. The RO2 isomerization via a six‐member ring transition state could happen in DPrC oxidation but not in dimethyl carbonate and diethyl carbonate oxidation, due to the different fuel molecular structure. Therefore, the subsequent reaction pathways via QOOH → O2QOOH → HO2Q = O + OH → OQ = O + OH were promoted and two OH radicals were released in this process. Moreover, it is conceivable that mid or long‐chain DACs could also exhibit an NTC phenomenon due to the increased potential for RO2 isomerization via a six‐ or seven‐member ring transition state, thereby increasing the likelihood of RO2 isomerization occurrence. [ABSTRACT FROM AUTHOR]

This study investigates the effects of boron nitride (BN) coating characteristics on the subsurface oxidation behavior of SiC/SiC composites in high‐temperature, water‐rich environments. Three types of coatings were examined: a crystalline stoichiometric BN, an amorphous BN, and a Si‐doped amorphous BN, the latter two containing 5–10 at% of oxygen and carbon. High‐resolution imaging and chemical analysis techniques were used to probe microstructural changes after oxidation at 1000°C for 1 or 12 h in flowing 20 vol% H2O, focusing on effects of coating thickness. Complementary chemical thermodynamic calculations and models for reaction‐ and transport‐controlled recession were used to interpret the experimental findings. Crystalline BN coatings produce open recession channels without forming borosilicate glass, a consequence of carbothermal reduction arising from C/CO produced through concomitant SiC oxidation. The combination of active oxidation and the relatively thick coatings in this system (ca. 1 µm) leads to a recession rate controlled by the intrinsic BN volatilization rate rather than the rate of gas transport. In contrast, amorphous coatings, both undoped and Si‐doped, readily oxidize to form borosilicate glasses that replace the BN. Broadly, the recession lengths increase with coating thickness. In the early stages, while the glass is boria‐rich and thus permeable to environmental oxidants, recession is controlled by the BN oxidation rate. As boria volatilizes, the silica concentration in the glass increases, eventually reaching the saturation limit and precipitating solid silica on the internal surfaces, essentially arresting further recession. [ABSTRACT FROM AUTHOR]

Organic cagelike frameworks are important and versatile skeletons for developing prospective energetic compounds because of their high intrinsic density, symmetry, stability, and derivability. Herein, we show the construction of three novel cagelike frameworks including dioxaadamantane, dioxaproadamantane, and dioxatwistane from 9-oxabicyclo[3.3.1]nonane-2,6-diene. In addition, their energetic derivatives were also prepared and characterized. Compared with our previous works, the introduction of more oxygen atoms into the framework gives the corresponding energetic derivative a better oxygen balance, significantly higher density, and detonation properties. These results imply that the oxygen-containing framework has the potential to be used for preparing new 3D energetic compounds with superior energy performance. [ABSTRACT FROM AUTHOR]

Since the milestone contribution by Chen and White in 2007, bioinspired non‐heme bis‐amino‐bis‐pyridylmethyl Fe complexes have been at the forefront of studies related to designing catalytic approaches for direct oxidative functionalization of aliphatic C−H bonds. This, however, has not developed into large‐scale synthetic applications to date. The present concept is aimed at briefly discussing the state‐of‐the‐art of non‐heme Fe catalyzed oxidations of organic molecules with H2O2, the current oxidant of choice of bioinspired oxidation catalysis, mostly focusing on C−H oxidations, and analyzing the peculiarities of their reactivity through the prism of potential applications in fine organic synthesis. [ABSTRACT FROM AUTHOR]

A general method for the synthesis of spiroacetals was investigated. Simple symmetrical [n,n]‐spiroacetals (n=5,6) can be prepared from α,ω‐alkanediols by their conversion to the respective ω‐benzyloxyalkyl bromides, addition of their Grignard reagents to ethyl formate, further oxidation of the resulting secondary alcohols and finally deprotection with spontaneous intramolecular acetalization. Access to the respective unsymmetrical [m,n]‐spiroacetals (m,n=5,6,7) was similarly achieved by addition of the above Grignard reagent to a ω‐benzyloxyalkanal, followed by the same reaction sequence. This method was further adapted for the synthesis of the unsubstituted structural core of natural spiroacetals oleocaran and elmonin, thus demonstrating its potential. [ABSTRACT FROM AUTHOR]

A divergent synthetic route to chondroitin sulfate (CS) disaccharide precursors, including rarer subtypes such as CS−D, has been developed. From common intermediates, a series of thioglycoside D‐glucosyl donors and 4,6‐O‐benzylidene protected D‐galactosamine acceptors are utilised in a robust glycosylation reaction, achieving β‐selectivity and consistent yields (60–75 %) on scales >2.0 g. A post‐glycosylation oxidation to D‐glucuronic acid and orthogonal protecting groups delivers access to CS−A, CS−C, CS−D, CS−E and CS−O precursor subtypes. Of further note is a 4‐O‐benzyl regioselective reductive ring opening of a 4,6‐O‐benzylidene protected disaccharide using dichlorophenylborane (PhBCl2) and triethylsilane (Et3SiH) to access a CS−D precursor, in 73 % yield over two steps. Finally, synthesis of a 6‐O‐sulfated CS−C disaccharide containing a conjugable anomeric allyl tether is completed. These materials will provide a benchmark to further synthesise and study chondroitin sulfates. [ABSTRACT FROM AUTHOR]

Phthalimide‐N‐oxyl radicals (PINO) are catalytically active hydrogen abstracting species generated from N‐hydroxyphthalimide (NHPI) – one of the most efficient and widely used organocatalysts for free‐radical oxidative CH‐functionalization processes. The self‐decay of PINO is one of the main limiting factors of NHPI usage, but currently there is no consensus on the mechanism of this important process. In the present work, quantitative EPR and NMR monitoring of PINO generation and degradation along with decay product analysis and control experiments allowed us to build a consistent picture of PINO decay chemistry and put together previously contradictory results. PINO yields achievable employing various oxidants were measured and compared for the first time. At least two PINO decay pathways were revealed: "trimerization" (with partial fragmentation, favored by high PINO concentrations at initial stage of decay), and medium oxidation favored by low PINO concentrations. The main PINO decomposition product, the "trimer" can easily be recycled back to NHPI. [ABSTRACT FROM AUTHOR]

2D transition metal halide oxides (TMHOs) have attracted much interest due to their intriguing ferroelectrics and excellent nonlinear optics, however, their susceptibility to oxidation makes their basic research and practical application a challenge. Therefore, it is crucial to understand the oxidation mechanism and explore effective strategies for protection. Here, taking van der Waals (vdWs) ferroelectric NbOI2 as an example, oxidation mechanisms and tuning the oxidation behaviors of NbOI2 and its heterostructures by a variety of in situ experiments and first‐principles calculations are discovered. The ambient‐pressure X‐ray photoelectron spectra reveal a self‐limiting oxidation in isolated NbOI2, driven by spontaneously formed iodine vacancies that react with oxygen molecules due to their lower formation and adsorption energies. For the heterostructures with a lower Fermi level (such as WSe2) than transition state VI@NbOI2 (NbOI2 rich in I‐vacancies), the charge transfer from NbOI2 to WSe2 drives the continuous and complete oxidation of NbOI2 flakes. Moreover, the heterostructures with a higher Fermi level (such as graphene) than VI@NbOI2 can weaken the oxidation of NbOI2. By linking the energy band structures to oxidation behavior, the work offers a new oxidation mechanism of 2D air‐sensitive materials and a crucial strategy for improving their chemical stability. [ABSTRACT FROM AUTHOR]

Tristructural isotropic (TRISO) fuel particles, developed for use in high‐temperature gas‐cooled nuclear reactors, can be subjected to oxidizing environments in off‐normal accident scenarios. In this study, surrogate TRISO fuel particles were oxidized at 1000–1350°C for 4 h in 20 kPa water vapor atmosphere balanced with ultrahigh‐purity helium gas. The oxide scale morphology and thickness were studied via scanning electron microscopy, focused ion beam, and transmission electron microscopy. The oxide thickness increased as the oxidation temperature was increased. Although the oxide scale at 1000°C was completely amorphous, pockets of crystalline oxide were observed on particles oxidized at 1200 and 1300°C. Kinetic analysis was performed to deduce the oxidation mechanism by determining the apparent activation energy using linear regression analysis. The oxidation mechanism was consistent for temperatures from 1000 to 1200°C with an activation energy of 412.4 ± 8.8 kJ/mol. The activation energy then dropped to approximately 201 ± 7.1 kJ/mol for temperatures 1200–1350°C. Therefore, there is a change in oxidation mechanism at ∼1200°C. This change is attributed to the existence of a network of significant bubbles in the oxide layer at higher temperatures, which serve as rapid diffusion pathways for the transport of oxidants from the surface to the SiC/SiO2 interface, instead of relying on the bulk diffusion through the SiO2 layer at lower temperatures where only small bubbles are present along the SiC/SiO2 interface. [ABSTRACT FROM AUTHOR]

In this study, natural asphalt was oxidized to synthesize a new nano-structure adsorbent for dye removal. The functionalization of natural asphalt by oxidation introduced new properties that influenced its activity. The process of oxidizing natural asphalt with potassium permanganate resulted in a low-cost adsorbent, which can potentially be a more affordable option compared with synthetic alternatives. Characterization analysis confirmed the enhanced surface area, improving dye interaction and adsorption. The interconnected channels and capillaries of the oxidized natural asphalt facilitated the capillary action drawing in liquids, including dyes. The distinctive porosity of natural asphalt oxide (NA-oxide) was noted, and the experimental results showed that the NA–oxide nanoadsorbent efficiently adsorbed cationic and anionic dyes in water, with maximum capacities of 14.68 mg.g−1, 17.81 mg.g−1 and 16.47 mg.g−1 for methyl orange, methylene blue and Rhodamine B, respectively. The study investigated various parameters, such as concentration, adsorption dose, pH, contact time, and temperature, affecting the dye removal process. Langmuir, Freundlich, and Temkin isotherms along with pseudo-first and pseudo-second-order kinetic equations were applied to assess the adsorption process, indicating that dyes adhered to the pseudo-first-order model and Langmuir isotherm. Analysis of MO, MB, and RhB dyes revealed conformity to Langmuir isotherm and first-order kinetics. Thermodynamic evaluations like ΔH°, ΔS°, and ∆G° displayed the exothermic and spontaneous nature of dye adsorption on the NA-oxide adsorbent. Furthermore, the absorbent displayed remarkable stability with a recovery rate of 98.45% after ten cycles, signifying its potential for enduring effectiveness in dye removal processes. [ABSTRACT FROM AUTHOR]

Vitex trifolia L. is widely used as a traditional medicine owing to its secondary metabolites. This study aimed to determine the phytochemical profiling of the ethanolic extract of V. trifolia leaves (EEVL). Additionally, biological activities were investigated, supported by molecular docking studies. The total flavonoid and phenolic contents of the EEVL were 35.25 ± 0.13 mg QE/g extract and 39.55 ± 1.43 mg GAE/g extract, respectively. The EEVL exhibits anti‐inflammatory activity with a half‐maximal inhibitory concentration (IC50) value of 153.59 µg/mL. The antioxidant activity of the EEVL exhibited an IC50 value of 20.41 ± 0.08 µg/mL with the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging method, a half‐maximal effective concentration value of 80.85 ± 0.39 µg/mL with the cupric‐reducing antioxidant capacity (CUPRAC) method, and a capacity of 180.58 mg QE/g extract with the ferric‐reducing antioxidant power (FRAP) method. At 16% concentration, the EEVL exhibited an antibacterial activity against some pathogenic bacteria. Molecular docking studies reported that casticin interacts with sodium diclofenac similarly toward 1PXX. However, artemitin exhibited better affinity toward 1HD2 than ascorbic acid. Thus, the EEVL has significant potential as a natural source for treating various diseases related to inflammation, oxidation, and infection. Moreover, screening of its active compounds is necessary for further exploration. [ABSTRACT FROM AUTHOR]

We report biochemical and structural studies on inhibiting bacterial S-adenosyl- L -homocysteine hydrolase by transition metal cations. Our results revealed diverse molecular mechanisms of enzyme inactivation. Depending on the cation, the mechanism is based on arresting the enzyme in its closed, inactive conformation, disulfide bond formation within the active site or oxidation of the intermediate form of a cofactor. [ABSTRACT FROM AUTHOR]

This study develops a biogenetic synthesis strategy using electrooxidation and heterodimerization of N-substituted pyrrolidine-1-carboxamides to create diverse analogues of the fissoldhimine alkaloid core. Under acidic conditions, 2-alkoxypyrrolidine-1-carboxamides from Shono oxidation formed endo-heterodimers with high yields and diastereoselectivity. Enantioselective heterodimerization using chiral phosphoric acid catalysis produced exo-heterodimers with high enantioselectivity. [ABSTRACT FROM AUTHOR]

Conventional oxidation processes for alkyl aromatics to ketones employ oxidants that tend to generate harmful byproducts and cause severe equipment corrosion, ultimately creating critical environmental problems. Thus, in this study, a practical, efficient, and green method was developed for the synthesis of aromatic ketones by applying a bis(2-butoxyethyl) ether/O2 system under external catalyst-, additive-, and base-free conditions. This O2-mediated oxidation system can tolerate various functional groups and is suitable for large-scale synthesis. Diverse target ketones were prepared under clean conditions in moderate-to-high yields. The late-stage functionalization of drug derivatives with the corresponding ketones and one-pot sequential chemical conversions to ketone downstream products further broaden the application prospects of this approach. [ABSTRACT FROM AUTHOR]

This study presents a novel application of Non-Linear Electrochemical Impedance Spectroscopy (NLEIS) in galvanostatic mode for the rapid, non-destructive assessment of metal degradation. By using galvanostatic mode instead of traditional potentiostatic methods, polarization-related challenges are mitigated, enabling more accurate and reliable analysis. The technique allows for the determination of corrosion rates (corrosion current) and material susceptibility to oxidation (Tafel coefficient) through a single measurement with a modulated AC perturbation signal. Theoretical assumptions of the method were validated through tests on both a non-linear model system and an experimental system. The proposed research methodology is highly effective for monitoring the condition of metallic materials in various environments, covering both anodic and cathodic processes. [ABSTRACT FROM AUTHOR]

A new wafer warpage model is proposed for the full process design of trench field‐plate (FP) power metal‐oxide‐semiconductor fileld‐effect transitors (MOSFETs) using large‐sized wafer. Trench FP power MOSFETs feature a deep trench and thick oxide at the wafer surface. Wafer warpage occurs due to the stress imbalance between the front and back sides of the wafer. This warpage leads to significant problems with transport errors in manufacturing equipment. This issue is expected to become even more crucial as lateral pitch narrowing is employed to reduce on‐resistance. In this study, two methods are compared to estimate the warpage of a 200 mm diameter Si‐wafer after trench etching and oxidation process. The mechanical stress generated by the oxidation process in several cell units is calculated using a 3D simulation. In the first approach, wafer warpage is converted from the displacement of the cell units. In the second approach, wafer warpage is estimated based on the surface film stress, which is calculated in the 3D simulation. The second approach shows good agreement with experimental results and is applicable to the 300 mm diameter Si process. This method yields more accurate measurements than the method using displacement. [ABSTRACT FROM AUTHOR]

Direct oxidation of methane into value‐added chemicals is considered as one of the holy grails in chemistry and catalysis. Considerable efforts have been devoted to developing advanced catalyst systems operated under mild conditions, and mononuclear metal species, which are currently in the spotlight of methane oxidation, have shown great advantages and addressed significant attention. In this concept, we highlight the recent breakthroughs and developments in monomeric metal species for low‐temperature (<100 °C) methane oxidation. Emphasis is put on the identification and validation of monomeric metal species as the intrinsic active sites. Promising characterization approaches for identifying catalytically relevant features of physicochemical properties of monomeric metal species are discussed, as well as the emerging insights on the development of in situ characterization technologies. Finally, the open challenges and outlooks for rational development of monomeric metal catalysts for methane valorization are examined for guiding further developments and inspiring the future work. [ABSTRACT FROM AUTHOR]

Research on polymer matrix composites has become increasingly important in both the academic and industrial sectors. The study of polymer-natural fiber composites, known for their eco-friendly properties, has gained significance. Sugarcane bagasse fibers, abundant as discarded agricultural byproducts, offer improved properties such as density, rigidity, strength, and cost-effectiveness, enhancing sustainability. As a result, experiments were performed on cellulose fibers pre-treated from sugarcane bagasse using 5% NaOH solution by simply soaking them for 4–5 h followed by washing with water. Further modifications involved esterification using phthalic anhydride and phthaloyl chloride via steam baths at 90 °C and oxidation using sodium percarbonate with a phase transfer catalyst (Adogen) at 80 °C. These chemically altered cellulose fibers exhibited significant peak changes in the FTIR spectra, a reduced crystallinity index in the XRD pattern, increased thermal stability as evidenced by TGA curve, and improved surface roughness in the SEM analysis. This paper emphasizes successful pretreatment procedures for isolating cellulose fibers from sugarcane bagasse and introduces three chemical treatments for surface functionalization which might find applications in the preparation of biocomposites. [ABSTRACT FROM AUTHOR]

Kalmanol, the flagship member of the kalmane diterpene family, possesses a complex and highly oxidized 5/5/8/5 tetracyclic skeleton with nine contiguous stereocenters and exhibits significant analgesic effects and cardiotoxic properties. We have achieved the efficient total synthesis of (+)‐kalmanol in 22 steps with 2.3 % yield. The synthesis featured a Rh‐catalyzed [5+2+1] cycloaddition reaction to construct 5/5/8 tricyclic skeleton, and a meticulously designed sequence of stereoselective oxidations of the 5/5/8/5 tetracyclic skeleton. [ABSTRACT FROM AUTHOR]

During recent years, the applicability of bi-, oleo- and emulgels has been widely studied, proving several advantages as compared to conventional fats, such as increasing the unsaturated fat content of products and being more sustainable for temperate regions as compared to tropical fats. Moreover, these alternative fat systems improve the nutritional profile, increase the bioavailability of bioactive compounds, and can be used as preservation films and markers for the inactivation of pathogens, while in 3D printing facilitate the obtaining of superior food products. Furthermore, bi-, oleo- and emulgels offer food industries efficient, innovative, and sustainable alternatives to animal fats, shortenings, margarine, palm and coconut oil due to the nutritional improvements. According to recent studies, gels can be used as ingredients for the total or partial replacement of saturated and trans fats in the meat, bakery and pastry industry. The evaluation of the oxidative quality of this gelled systems is significant because the production process involves the use of heat treatments and continuous stirring where large amounts of air can be incorporated. The aim of this literature review is to provide a synthesis of studies to better understand the interaction of components and to identify future improvements that can be applied in oil gelling technology. Generally, higher temperatures used in obtaining polymeric gels, lead to more oxidation compounds, while a higher concentration of structuring agents leads to a better protection against oxidation. Due to the gel network ability to function as a barrier against oxidation factors, gelled matrices are able to provide superior protection for the bioactive compounds. The release percentage of bioactive molecules can be regulated by formulating the gel matrix (type and concentration of structuring agents and type of oil). In terms of food products, future research may include the use of antioxidants to improve the oxidative stability of the reformulated products. [ABSTRACT FROM AUTHOR]

MCrAlY coatings are widely used in high-temperature applications against oxidation and corrosion. Under high-temperature conditions, selective alumina formation which provides higher resistance to oxygen penetration is possible using the MCrAlY coatings. Metallic MCrAlY alloys can be produced by many coating techniques. The produced coatings can also be modified using surface treatments. In the present study, CoNiCrAlY was deposited on a 316L stainless steel (S.S.) substrate using the high-velocity oxygen liquid fuel (HVOLF) technique. The deposited coating was subjected to a laser surface remelting process. The remelted and as-sprayed CoNiCrAlY coatings were subjected to isothermal oxidation tests for 5, 25 and 50 h at 1050 °C. The produced and oxidized samples were characterized using scanning electron microscopy (SEM), SEM line and elemental mapping analysis, x-ray diffractometer, and Image-Pro Plus 6 software program. After the examination of oxidized samples, the laser-remelted coating exhibited superior oxidation resistance compared to the as-sprayed coating due to the eliminated porosities beneath the surface regions and the formation of the alpha alumina layer. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the preservative properties of alga Gelidium sp. flour when included in the glazing medium employed for the frozen storage (−18 °C) of horse mackerel (Trachurus trachurus). Different concentrations (low, medium, and high) of an aqueous extract were tested and compared to a control water-glazing condition. Quality changes (lipid oxidation and hydrolysis, fatty acid (FA) profile, and trimethylamine (TMA) formation) were determined after 3- and 6-month storage periods. A general quality loss (lipid oxidation with hydrolysis development and TMA formation) with the frozen storage period was detected in all samples. The presence of an alga flour (AF) extract in the glazing medium led to a lower (p < 0.05) TBARS and fluorescent compound formation and to higher (p < 0.05) polyene values in frozen fish. Furthermore, a preserving effect on free fatty acids was detected in AF-treated fish. On the contrary, the AF-glazing treatment did not affect (p > 0.05) the TMA formation and the total n3/total n6 FA ratio. In general, preservative effects were found to be higher in frozen fish corresponding to the medium concentration tested. Current results show the potential of Gelidium sp. flour as a natural source of preservative hydrophilic compounds for the quality enhancement of frozen horse mackerel. [ABSTRACT FROM AUTHOR]

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The work presented here investigates whether the TpMesFe+ moiety, which had been previously found to mediate the dioxygenation of cysteine and cysteamine, can do the same with simple thiols, which are not functionalized by an amine group. Accordingly, the complexes TpMesFeSR (R=Ph, iPr) were synthesized and after full characterization exposed to O2. They were found to react unselectively to yield sulfinates, disulfides, and thiosulfones as products. The sulfinate complex TpMesFeO2S‐p‐Tol was prepared independently and found to be air‐stable, suggesting that the additional products are not formed via overoxidation or subsequent reactions of coordinated sulfinate product. To investigate whether the larger reaction space, opened up due to the missing amine donor is responsible, a Tp‐ligand functionalized by a pyridyl donor was employed. A corresponding Tp‐iron(II) chlorido complex was prepared and converted through salt metathesis reactions into the respective thiolate analogues, which were fully characterized and structurally authenticated. However, subsequent O2 reactivity studies did not show an improved selectivity. The reason may lie in a more open reaction pocket in combination with an electronic situation which is less ideal than in case of TpMesFe(cysteamine). [ABSTRACT FROM AUTHOR]

We reported a one‐pot photocyclization/ oxidation cascade of N‐aryl acrylamides to afford quinoline‐2‐ones. Thioxanthone was used as a bifunctional energy transfer agent to mediate both photocyclization and generation of singlet oxygen, the latter facilitates the dehydrogenation of dihydroquinoline‐2‐one intermediate. This cascade strategy also supports the 5‐endo‐trig cyclization to synthesize tetrahydrocarbazolones from phenylamino cyclohexenones. [ABSTRACT FROM AUTHOR]

Organic electrosynthesis has become a green, efficient and sustainable alternative to traditional organic transformation for the redox reactions. In this connection, indirect electrolysis employing redox mediators is attaining increasing significance as it offers a chance to improve reaction selectivity and avoids the over‐oxidation/reduction issues encountered in direct electrolysis. Triarylamines and triarylimidazoles, as representative organic molecular mediators, have attracted widespread attention in recent years due to the advantages of well‐defined easy structural modification and tunable redox ability. Hence, in this minireview, the recent growth of triarylamine and triarylimidazole derivatives mediated electrochemical oxidation reactions were presented, highlighting the structural optimization, electrochemical performance and reaction mechanism of these organic mediators. Moreover, the photocatalytic and photoelectrocatalytic cases with these molecular mediators were also highlighted. To conclude, the current challenges and future prospects of this field are also discussed. [ABSTRACT FROM AUTHOR]

A method for synthesizing pyrimido[1,2‐a]indol‐4‐ol heteroarenes via a Cp*Rh(III)‐catalyzed cascade C−H activation/annulation strategy employing N‐methoxyindoleamides and isoxazolones is developed. Also, a framework of 3‐methoxy‐2,3‐dihydro‐[1,3,5]triazino[1,2‐a]indole‐4,10‐dione was successfully synthesized via a Cp*Rh‐catalyzed C−H activation/annulation/oxidation reaction between N‐(methyloxy)‐1H‐indole‐1‐carboxamide and isoxazolones. These reactions demonstrated the suitability of several substrates, compatibility with numerous functional groups, and mild reaction conditions. Preliminary mechanistic investigations have been completed. [ABSTRACT FROM AUTHOR]

Compounds bearing the sulfoxide moiety display an important class of molecules in pharmaceutical industry. Many efforts have been made towards the development of novel, sustainable, easy‐to‐execute and industrially friendly processes. A novel iodonium‐salt‐mediated oxidation protocol for the conversion of sulfides into the corresponding sulfoxides is reported, employing DMSO as the oxidant. Several sulfides decorated with various functional groups were tested, leading to the corresponding products in good to excellent yields with remarkable chemoselectivity. The oxidation protocol was successfully applied to the synthesis of the pharmaceutical active ingredients (APIs) Sulforaphane and Modafinil. [ABSTRACT FROM AUTHOR]

Indoleamine 2,3‐dioxygenase (IDO) is a monomeric heme enzyme that catalyzes the oxidative cleavage of tryptophan (L‐Trp) to form N‐formyl‐kynurenine. Similar to other heme proteins, IDO only binds to O2 when the heme iron is ferrous (FeII), thereby rendering the enzyme active. Thus, ascorbate (Asc, a reducing agent) and methylene blue (MB, an electron carrier) are commonly added to in vitro IDO assay systems. However, Asc and MB have been recently reported to significantly impact the measurement of the enzymatic parameters of vertebrate IDO. Aspergillus fumigatus is a filamentous fungus and the most common cause of invasive aspergillosis; it has three IDO genes (IDOα, IDOβ, and IDOγ). The FeII–O2 IDOs of A. fumigatus, particularly FeII–O2 IDOγ, have relatively long half‐lives in their autoxidation; however, the autoxidation was accelerated by Asc. Similar to vertebrate IDOs, Asc acted as a competitive (or mixed‐competitive) inhibitor of the IDOs of A. fumigatus. A positive correlation (in the order of IDOγ > IDOβ > IDOα) was observed between the inhibitory sensitivity of the IDOs to Asc and the facilitation of their autoxidation by Asc. The FeII–O2 IDO can repeat the dioxygenase reaction as long as it reacts with L‐Trp; however, substrate‐free FeII–O2 IDO is converted into inactive FeIII–IDO by autoxidation. Thus, L‐Trp (which keeps the IDO active) competes with Asc (which inactivates IDO by accelerating autoxidation). This is probably why Asc, which is structurally quite different from L‐Trp, appears to function as a competitive (or mixed‐competitive) inhibitor of IDOs. [ABSTRACT FROM AUTHOR]

A heterogeneous photocatalyst was assembled through electrostatic immobilization of a cationic porphyrin at the surface of functionalized carbon nanotubes. The supra‐molecular nanohybrid catalyst was valorized in the aerobic photo‐oxidation of sulfides to the corresponding sulfoxides. The process operated selectively under visible light, with low catalytic loading, in water as the solvent, and the catalyst was readily recycled and reused. [ABSTRACT FROM AUTHOR]

Knölker complexes have been recently used to perform the catalytic C1‐oxidation of unprotected sugars into sugar lactones. This oxidation method remained limited by the stability of the catalyst with the polyhydroxylated substrates. Our objective is now to overcome these limitations and extend this method to more challenging substrates such as disaccharides. We proposed in this paper two original designs of Knölker‐type complexes conceived to promote secondary H‐bond interactions with the OH groups of the substrates to stabilise the system and favour the transformation. In total, 8 novel pre‐catalysts were synthesised, fully characterised and applied in the anomeric oxidation of several sugar derivatives. Two of these new complexes proved to be more efficient than the Knölker complex for the oxidation of disaccharides. Moreover, a preliminary DFT study revealed the presence of H‐bonds interactions between the substrate and the oxygen atom on the ligand arm of the best complexes suggesting a beneficial role of this heteroatom on the catalytic efficiency. [ABSTRACT FROM AUTHOR]

Mixed lead‐tinv halide (LTH) perovskite solar cells (LTH‐PSCs) can reduce the toxicity concerns of full lead‐based PSCs and potentially optimize the bandgap to maximize efficiency. However, commonly used hole‐transporting material (HTM) 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenyl‐amine)9,9′‐spirobifluorene (Spiro‐OMeTAD) with additional dopants Li‐bis(trifluoromethanesulfonyl) imide (Li‐TFSI) and 4‐tert‐butylpyridine (t‐BP) deteriorate oxidation Sn2+ to Sn4+ leading to trap formation. Here, the study introduces a novelty Sn‐friendly HTM for Sn‐rich LTH‐PSCs, combining Spiro‐OMeTAD with 4‐Isopropyl‐4′‐methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (dpi‐TPFB) as a dopant and blended with poly(3‐hexylthiophene‐2,3‐diyl) (P3HT). This blended HTM avoids the harmful effects of Li‐TFSI and t‐BP dopants and leverages the beneficial hydrophobic properties of P3HT, which predominantly resides on the surface with a face‐on orientation. This arrangement not only enhances charge transport and extraction but also improves device stability by protecting the perovskite from environmental factors. Optimizing the P3HT concentration of blended HTM achieved a PCE of 17.27%, the highest reported for n‐i‐p structured Sn‐rich mixed LTH‐PSCs. This HTM also significantly improved device stability, maintaining over 90% of the initial PCE after 3000 h of storage and 80% under maximum power point tracking (MPPT) for 550 h in the air. [ABSTRACT FROM AUTHOR]

Se-doped Ni(OH)2 showed greatly improved catalytic performance for urea oxidation due to the enhanced urea molecules' adsorption ability on the Se–Ni(OH)2 electrode and weakened poisoning effect by effectively reducing the energy barrier for CO2 adsorption. [ABSTRACT FROM AUTHOR]

The bond dissociation enthalpy of the N–H bond was calculated for the following compounds: 1-((E)-1,5-diphenylpent-1-en-4-yn-3-ylidene)-2-(o-tolyl)hydrazine, 1-((E)-1-(4-methoxyphenyl)-5-phenylpent-1-en-4-yn-3-ylidene)-2-phenylhydrazine, 1-((E)-1-phenylpent-1-en-4-yn-3-ylidene)-2-(p-tolyl)hydrazine, 1-((E)-1-(4-methoxyphenyl)-5-trimethylsilyl-1-en-4-yn-3-ylidene)-2-phenylhydrazine, and 1-((E)-1-(toiphenyl-2)-5-phenylpent-1-en-4-yn-3-ylidene)-2-phenylhydrazine. The calculations were performed by the M06-2X/6-311+G(2df,2pd)//B3LYP/6-31G(d) method using the homodesmotic approach. The bond dissociation enthalpy is lower than 77 kcal/mol for all the cross-conjugated hydrazone derivatives under study. The experimental rate constants for the reactions of the derivatives with peroxyl radicals in chlorobenzene during the initiated styrene oxidation are comparable to those of aromatic amines and are in the range (1.1–2.5) × 105 M−1 s−1. The stoichiometric inhibition coefficient depends on the structure of the derivatives and varies from 0.7 to 1.9. The inhibition is discussed within the framework of the radical mechanism. [ABSTRACT FROM AUTHOR]

The increasing energy shortage and environmental pollution make the use of clean and efficient alternative fuels an effective way to solve the emission problem. Diesel from indirect coal liquefied (DICL) is a clean and efficient alternative fuel for diesel engines. The composition and chemical kinetics mechanism of DICL research contributes to a better understanding of combustion and pollutant formation process. The components of DICL were analysed by gas chromatography-mass spectrometry (GC-MS). The proportion of normal alkanes contained in DICL is particularly high, 93.82%, which proves that its reactivity is particularly good. The mixture of n-dodecane and iso-octane was selected as the surrogates of DICL. The oxidation process of DICL surrogates was examined by a jet-stirred reactor (JSR) over the temperature range of 500–890 K. A detailed kinetic mechanism of surrogates encompassing 1356 species and 6008 reactions was constructed. The critical reactions associated with the reactivity of surrogates were adjusted by the sensitivity analysis method to increase the accuracy of mechanism prediction. The predicted value of the improved mechanism is in good agreement with the experimental value. The improved mechanism can reasonably predict the oxidation process and the ignition characteristics of DICL and the improved mechanism can provide a good reference value for the subsequent analysis of combustion and emission problems of DICL. Abbreviations: C/H, C/H ratio; CN, cetane number; DDCL, direct coal liquefy diesel; DICL, Diesel from indirect coal liquefied; GC-MS, gas chromatography-mass spectrometry; HMN, 2,2,4,4,6,8,8-heptamethylnonane; HXN, n-hexadecane; IDT, ignition delay time; JSR, jet-stirred reactor; LHV, low heating value; LLNL, Lawrence Livermore National Laboratory; NSRL, National Synchrotron Radiation Laboratory; NTC, negative temperature coefficient; PICS, photoionization cross section; PRF, gasoline substitute; PSR, perfectly stirred reactor; SVUV-PIMS, Synchrotron VUV photoionization mass spectrometry; TOF-MS, time-of-flight mass spectrometer [ABSTRACT FROM AUTHOR]

Geraniol is a compound belonging to the group of monoterpenes that finds many applications in organic syntheses, medicine and cosmetics. The following properties of geraniol and its derivatives are of particular interest in medicine: its anti-inflammatory, antioxidant, antimicrobial and anticancer effects. The geraniol oxidation process was carried out using a mineral of natural origin—vermiculite. Vermiculite is a catalyst that perfectly fits into modern trends in the organic industry, where the aim is to use cheap, renewable and relatively easily available catalytic materials (vermiculite is found on continents including Africa, North America, South America, Australia and Asia). Preliminary studies on the oxidation process of geraniol on vermiculite was carried out in a glass apparatus using molecular oxygen supplied by means of a bubbler and magnetic stirrer with a heating function. During the oxidation process of geraniol on vermiculite, the influence of the following parameters was examined: the temperature, amount of catalyst and reaction time. The main parameters of the process, on the basis of which the most favorable process conditions were selected, were the selectivity of the transformation to 2,3-epoxygeraniol, citral and 2,3-epoxycitral, and the conversion of geraniol. The composition of the post-reaction mixtures was determined qualitatively and quantitatively using the gas chromatography method. In addition, vermiculite was subjected to instrumental tests, such as XRD, SEM, EDX, FTIR and UV-VIS. Moreover, the specific surface area, pore volume and pore volume distribution were estimated on the basis of N2 sorption at −196 °C and also the acid-site concentration in vermiculite was established. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (MNPs) based on magnetite (Fe3O4) are attractive catalyst supports due to their high surface area, easy preparation, and facile separation, but they lack stability in acidic reaction media. The search for MNPs stable in oxidative acidic reaction media is a necessity if one wants to combine the advantages of MNPs as catalyst supports with those of iodine(III) reagents being environmentally benign oxidizers. In this work, immobilized iodophenyl organocatalysts on magnetite support (IMNPs) were obtained by crossed-linking polymerization of 4-iodostyrene with 1,4-divinylbenzene in the presence of MNPs. The obtained IMNPs were characterized by TGA, IR, SEM, STEM, and HAADF to gain information on catalyst morphology, average particle size (80–100 nm), and their core–shell structure. IMNP-catalysts tested in (i) the α-tosyloxylation of propiophenone 1 with meta-chloroperbenzoic acid (m-CPBA) and (ii) in the oxidation of 9,10-dimethoxyanthracene 3 with Oxone® as the side-oxidant showed a similar performance as reactions using stoichiometric amounts of iodophenyl. The developed IMNPs withstand strong acidic conditions and serve as reusable organocatalysts. They are recyclable up to four times for repeated organocatalytic oxidations with rates of recovery of 80–92%. This is the first example of a—(4-iodophenyl)polystyrene shell—magnetite core-structured organocatalyst withstanding strong acidic reaction conditions. [ABSTRACT FROM AUTHOR]

In order to explore the possibilities of increasing the hydrophilicity of carbon-based adsorbents, catalysts, or electrode materials in aqueous solutions, the oxidation of wood-based activated biochar using H2O2 was investigated. The properties of oxidized activated biochar obtained at different activation temperatures (600, 700, and 800 °C) and H2O2 oxidized for 15–180 min were investigated using the characteristics of surface functionality, elemental composition, porous structure, contact angle measurements, FTIR spectroscopy, and immersion calorimetry. It was observed that the optimal oxidation time was different for each sample depending on activation temperature, and the degree of oxidation can be tailored by changing the oxidation time. The course of oxidation depends on the degree of graphitization and functionalization, determined by the activation temperature. It was established that the highest degree of oxidation and increase in wettability is observed for samples with the lowest degree of activation obtained at a temperature of 600 °C. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) is incinerated to reduce the volume and recover energy and materials. The generation of MSW has been increasing over the past few decades due to the increase in population and changing consumption habits. Rising environmental and economic concerns have increased the importance of waste treatment and recovery. Currently, MSW may take three alternate or parallel routes: direct recycling, incineration, or landfill, depending on the country and location. MSW incineration has three products in addition to energy: bottom ash, fly ash, and off-gas. After incineration, bottom ash usually still contains many materials to be recovered, such as glass, ceramics, and metals with a degree of oxidation. This study focuses on aluminium recovery from MSW incineration bottom ash from two different countries. The 2–30 mm fraction of aluminium particles was characterized in terms of its size, shape, and oxide thickness, and its effects on aluminium recovery were investigated. In addition, the ability of mechanical pre-treatment to remove oxides prior to melting was studied. The results were compared with the analytical modeling developed in this study. An increasing particle size and surface area resulted in an increase in aluminium recovery. Mechanical pre-treatment increased the yield for smaller particles to a larger extent than larger particles due to the difference in the oxide/metal ratio. [ABSTRACT FROM AUTHOR]