Search

Spontaneous combustion of coal gangue (CG) hills has caused varieties of secondary disasters that seriously endanger the ecological environment of the world. The emission law of index gases and their oxidation kinetics during the secondary oxidation process of CG with different ranks of oxidation were studied by using the temperature programmed device and online mass spectrometer (MS). Fourier transform infrared spectroscopy (FTIR) was used to reveal the changes of the CG internal active functional groups. The results showed that the energy required for the combustion of CG with low rank of pre-oxidation was significantly lower than that of the raw sample. However, as the oxidation rank increased, due to amounts of volatile components were released in the process of oxidation reaction, the CG in the combustion process of the emission of index gases and its oxygen consumption rate gradually reduced; the rapid oxidation stage shifted to the direction of the high temperature. In this study, the risk of spontaneous combustion of CG after oxidation at 80 ℃ under 3% oxygen concentration was the strongest. The results of this paper are of great guiding significance for exploring the spontaneous combustion characteristics of CG hills and their prevention by traditional covering method. [ABSTRACT FROM AUTHOR]

Although direct methanol fuel cell (DMFC) is regarded as a promising power source to establish green energy conversion system, its overall performance is largely limited by the slow methanol oxidation kinetics of current anode catalysts. Herein, we demonstrate a robust and facile bottom-up strategy for the controllable construction of ultrafine PtRu alloy nanoparticles immobilized onto three-dimensional (3D) interconnected Ti 3 C 2 T x MXene-graphene frameworks (PtRu/MXene-G) through a co-assembly process. Interestingly, the utilization of 3D porous MXene-G matrix provides strong interfacial interactions with alloy nanocrystals and promotes the transportation of both reactant and electron during the electrocatalytic process, while the introduction of Ru atoms ameliorates the Pt electronic structure and generates plentiful hydroxyl species for the oxidative removal of CO byproducts. Working together, the resulting PtRu/MXene-G nanoarchitecture with an appropriate Pt/Ru atomic ratio exhibits exceptional methanol oxidation properties in terms of a large electrochemically active surface area of 101.8 m2 g−1, a high mass (specific) activity of 1779.5 mA mg−1 (1.75 mA cm−2), and good long-term stability, all of which are significantly superior to those of conventional Pt/carbon black, Pt/G, Pt/MXene, and Pt/MXene-G catalysts with an identical Pt usage. A facile and robust bottom-up approach is developed to the controllable synthesis of ultrafine PtRu alloy nanoparticles immobilized onto 3D interconnected porous Ti 3 C 2 T x MXene-graphene frameworks, which exhibit exceptional electrocatalytic performance towards the methanol oxidation reaction. [Display omitted] • The bottom-up construction of PtRu-decorated 3D MXene-graphene frameworks is achieved. • The 3D porous MXene-graphene matrix is favorable for the transportation of both reactants and electrons. • The ultrafine PtRu nanocrystals with homogeneous dispersion provides numerous accessible catalytic sites. • The optimized hybrid nanoarchitecture expresses exceptional methanol oxidation performance. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the high temperature oxidation behavior of Ti and C-added FeCoCrNiMn high entropy alloys (HEAs). Design/methodology/approach: Cyclic oxidation method was used to obtain the oxidation kinetic profile and oxidation rate. The microstructures of the surface and cross section of the samples after oxidation were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Findings: The results show that the microstructure of the alloy mainly consisted of FCC (Face-centered Cubic Structure) main phase and carbides (M7C3, M23C6 and TiC). With the increase of Ti and C content, the microhardness, strength and oxidation resistance of the alloy were effectively improved. After oxidation at a constant temperature of 800 °C for 100 h, the preferential oxidation of chromium in the chromium carbide determined the early formation of dense chromium oxide layers compared to the HEAs substrate, resulting in the optimal oxidation resistance of the TC30 alloy. Originality/value: More precipitated CrC can preferentially oxidize and rapidly form a dense Cr2O3 layer early in the oxidation, which will slow down the further oxidation of the alloy. [ABSTRACT FROM AUTHOR]

The kinetics of the liquid-phase oxidation of cumene (RH) with molecular oxygen in the presence of KMnO4 and N-hydroxysuccinimide (NHSI) is studied. An increase in the reaction rate when adding acetic acid is established. An synergistic effect of KMnO4 and NHSI in aerobic oxidation of RH is found. This can be associated with the formation of C-centered (R⦁) and O-centered (SINO⦁) radicals that participate in the chain initiation stage and the catalysis of the chain propagation stage by the SINO⦁ radical. [ABSTRACT FROM AUTHOR]

The kinetics of oxidation/reduction of the primary donor of photosystem 1 (PS1) P700, plastocyanin (PC), and ferredoxin (Fd) in the first leaves of barley seedlings under exposure to high-intensity light (2000 μmol∙quanta∙m–2·s–1, 30 min) and elevated temperature (40°C, 3 h) were studied using differential absorption photometry. Exposure to high-intensity light increased the accumulation of the oxidized form of PS1 reaction center P700+, oxidized PC, and reduced Fd. Reduced Fd was not reoxidized under the same conditions on exposure to red and far-red light. The accumulation of P700+, PC+, and Fd – increased in barley seedlings exposed to elevated temperatures. Also, reoxidation of leaf Fd accelerated under red light. Oxidized Fd did not accumulate under far-red light. It was concluded that photo-independent electron flow through Fd under light stress and alternative electron flows involving the plastoquinone pool under heat stress were activated. [ABSTRACT FROM AUTHOR]

It is common knowledge that in-situ combustion is highly promising method for improving heavy oil recovery. The present research explores the effects of Cobalt-ligated catalysts derived from sunflower oil (CoSFO) and tall oil (CoTO) on heavy oil oxidation, aiming to enhance in-situ combustion process. Through differential scanning calorimetry (DSC) we assessed the oxidation kinetics of heavy oil in the presence and absence of these catalysts. Our findings indicate that both CoSFO and CoTO significantly improve the oxidation process, particularly in the high-temperature oxidation (HTO) phase crucial for combustion front stabilization. Notably, CoTO demonstrated superior efficacy in reducing oxidation times across all conversion levels, suggesting its potential to optimize the efficiency of EOR techniques. This research highlights the promise of Cobalt-ligated catalysts in advancing heavy oil recovery and suggests directions for future studies to further investigate their industrial applications. [ABSTRACT FROM AUTHOR]

The possibilities of obtaining aluminum matrix composite materials of the composition Al–Al2O3 are considered by the method of liquid-phase oxidation of aluminum by purging the melt with oxygen. The obtained materials are a two-phase system with different concentrations of the solid phase. An algorithm for calculating the kinetics of aluminum oxidation in obtaining the oxide phase of an aluminum matrix composite is proposed. It is established that the beginning and completeness of the reaction on the surface of the gas bubble determines the synthesis of the oxide phase and is determined by the functions T(t), h(t) in the region of dynamic time delay, which, in turn, the queue is revealed as a function of the temperature in the contact zone of the gas bubble with the melt, taking into account the duration of the heating of the bubble along the cross section and the radius of the bubble itself. The microstructures of the obtained materials with different structural-phase state with variations in the time of purging and oxygen supply to the aluminum melt are presented. [ABSTRACT FROM AUTHOR]

Effective municipal solid waste (MSW) management and waste-to-resource recovery has a key potential to play a vital role in economic growth of a country. MSW contains the different items of daily use that makes its composition mix in nature. Different waste-to-energy techniques are already available to treat this waste but these techniques always require some pretreatments such pre-separation and pre-drying of mix MSW that makes these processes less techno-economic to apply on large scales. To provide an effective solution to this problem, potential wet oxidation technique has been reviewed in this study. In the first section, the statistics for MSW generation and composition for different cities in Poland have been presented to show the existence of maximum organic content which can be converted to useful organic compounds. In the later section, the wet oxidation technique and its various aspects have been reviewed in detail to justify the potential of this technique to treat mix MSW at larger scales to produce different valuable products in the context of waste-to-resource recovery. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering 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.)

G115 steel is a novel martensitic heat-resistant steel, primarily utilized in the main steam pipelines and collectors of ultra-supercritical thermal power units. However, the oxidation resistance of martensitic steels in the high-temperature steam environment is usually suboptimal, significantly affecting the efficiency of power plants. In this paper, shot peening (SP) is employed as a surface treatment method for G115 steel, and the oxidation kinetics, oxide layer thickness, and microstructure of shot-peened G115 samples are compared with those of G115 steel. The results indicate that in the 650 °C steam environment, the oxidation kinetics of the shot-peened samples follow the parabolic law and that the oxidation weight gain is significantly smaller than that of the non-shot-peened samples. The higher the SP intensity, the smaller the oxidation weight gain and the better the oxidation resistance. This can be attributed to the fragmentation of the grains in the surface layer caused by external stress during SP, which creates a multitude of grain boundaries that can provide rapid diffusion pathways for corrosion-resistant Cr atoms, resulting in the accelerated outward diffusion of Cr atoms from the substrate. Simultaneously, a continuous and dense FeCr2O4 protective layer is produced at the interface between the SP layer and the substrate, obstructing the inward diffusion of oxygen and enhancing the oxidation resistance of G115 steel. [ABSTRACT FROM AUTHOR]

To explore the spontaneous combustion characteristics and hazards of the low-temperature oxidation (LTO) stage in the process of spontaneous combustion of coal and mudstone, the pore structure, spontaneous combustion characteristic parameters, and exothermic characteristics of coal and mudstone were tested and studied, and the oxidation kinetic parameters were calculated. The results show that mudstone has a larger specific surface area and pore volume than coal. From the fractal characteristics, the pore structure of mudstone is more complex than that of coal. According to the comparison of theoretical and actual gas generation and oxygen consumption rate curves, it is found that there is an interaction between coal and mudstone in the LTO process. With the increase of mudstone mass ratio, gas production, and its oxygen consumption rate increase. Among them, CM-4 (Coal:Mudstone = 1:1) has the highest exothermic intensity and the exothermic factor (A) and fire coefficient (K) increase with the increase of mudstone content. The apparent activation energy of the mudstone sample is lower than that of the raw coal, indicating that the sample after adding mudstone is more likely to have spontaneous combustion in the LTO stage. [ABSTRACT FROM AUTHOR]

TiC and crystalline (Ti,Nb) 3 SiC 2 based dual-layer is prepared on SUS430 alloy by DC magnetron sputtering followed by annealing at 1000 °C for 20 h. The oxidation of TiC/TNSC coated alloy at 800 °C for 500 h follows the parabolic law with a low rate constant of 5.4 × 10−15 g2 cm−4 s−1. The formed oxide scale is composed of Cr 2 O 3 /MnCr 2 O 4 dominated inner layer and outer layer of Nb-doped TiO 2 and SiO 2 uniform mixture. Owing to the barrier effect of TiC layer and dense oxide scale, outward diffusion of Cr and Mn is efficiently suppressed, resulting in the low Cr content in the outer oxide layer, which is beneficial to the reduced volatilization of Cr oxide. Furthermore, the ASR of the formed oxide scale at 800 °C is 15.87 mΩ cm2, suggesting excellent conductivity. It is concluded that the TiC/(Ti,Nb) 3 SiC 2 coating can significantly improve the oxidation resistannce and electrical property of SUS430 alloy, endowing it potential application as SOFC interconnect protective coating. • The TiC and crystalline (Ti,Nb) 3 SiC 2 based dual-layer coating is prepared. • The oxidation kinetics of coated alloy follows the parabolic law. • (Ti,Nb) 3 SiC 2 based coating is oxidized into a mixture layer of TiO 2 and SiO 2. • Outward diffusion of Cr is suppressed by the TiC and dense oxide layer. • The oxide layer possesses good electrical property with the ASR of 15.87 mΩ.•cm2. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries with a high theoretical energy density of 2600 Wh·kg−1 are hindered by challenges such as low S conductivity, the polysulfide shuttle effect, low S reduction conversion rate, and sluggish Li2S oxidation kinetics. Herein, single-atom non-noble metal catalysts (SACs) loaded on two-dimensional (2D) vanadium disulfide (VS2) as the potential host materials for the cathode in Li–S batteries were investigated systematically by using first-principles calculations. Based on the comparisons of structural stability, the ability to immobilize sulfur, electrochemical reactivity, and the kinetics of Li2S oxidation decomposition between these non-noble metal catalysts and noble metal candidates, Nb@VS2 and Ta@VS2 were identified as the potential candidates of SACs with the decomposition energy barriers for Li2S of 0.395 eV (Nb@VS2) and of 0.162 eV (Ta@VS2), respectively. This study also identified an exothermic reaction for Nb@VS2 and the Gibbs free energy of 0.218 eV for Ta@VS2. Furthermore, the adsorption and catalytic mechanisms of the VS2-based SACs in the reactions were elucidated, presenting a universal case demonstrating the use of unconventional graphene-based SACs in Li–S batteries. This study presents a universal surface regulation strategy for transition metal dichalcogenides to enhance their performance as host materials in Li–S batteries. [ABSTRACT FROM AUTHOR]

This study presented the development of a reaction kinetics scheme based on saturates–aromatics–resins–asphaltenes (SARA) fractions to represent the complicated chemical reactions occurring during high-pressure differential scanning calorimetry (HP-DSC) tests. The heat release characteristics during heavy crude oil combustion were analyzed from a set of HP-DSC results. On the basis of this analysis, an improved reaction kinetics model, including low-temperature oxidation (LTO) reactions of SARA fractions, cracking of oxidized asphaltenes, and coke combustion, was established. Following that, this model was incorporated into Computer Modeling Group STARS to simulate the HP-DSC results. Both activation energy and frequency factor of each reaction were continuously tuned until the correct kinetics parameters were obtained by matching the simulation data with the HP-DSC experimental data. The experimental results indicated that the heavy crude oil experienced greater heat release due to LTO rather than high-temperature oxidation at 5 MPa, which differed from the results observed at atmospheric pressure. The simulation results showed that the energy required to activate the oxidation reactions in the HP-DSC experiments was similar to that in the numerical simulation. However, the oil sample was subjected to higher molecular collision frequency in the HP-DSC experiments than in the numerical simulation. Therefore, more attention should be given to adjusting frequency factor when determining the oxidation kinetics parameters in the numerical model. Overall, the SARA-based oxidation kinetics model successfully simulated the exothermic characteristics of the heavy oil during heating. [ABSTRACT FROM AUTHOR]

Accurate soot modeling in flames is one important tool contributing to an understanding of soot behavior in combustion. Soot models reflect the four principal processes that govern soot dynamics: nucleation, coagulation, surface growth, and oxidation. Existing oxidation models reflect both the temperature-dependent surface oxidation chemical kinetics and also the fact that the surfaces become less reactive as they age. This surface deactivation process has been modeled primarily by using in-flame soot measurements as a basis for developing functional forms and parameters to describe the decay of α, the ratio of active oxidation sites divided by total surface sites. These existing models, in general, overpredict oxidation rates in turbulent diffusion flames. This study presents an alternative soot aging factor model that is based on the analogous process of coal char oxidation deactivation, a well-studied problem. The proposed framework provides a basis for application to a wide range of turbulent diffusion flames. This new model is configured to provide the same parameter α that appears in existing approaches. As such it can be easily applied to the existing published models. The approach is implemented in the fixed-pivot sectional soot model, with the performance compared against literature data for ethylene/air turbulent diffusion flames. With only very minor adjustment from the baseline parameters developed for coal char, the model shows good agreement with the literature flame data. [ABSTRACT FROM AUTHOR]

Cu‐thiosemicarbazones have been intensively investigated for their application in cancer therapy or as antimicrobials. Copper(II)‐di‐2‐pyridylketone‐4,4‐dimethyl‐thiosemicarbazone (CuII‐Dp44mT) showed anticancer activity in the submicromolar concentration range in cell culture. The interaction of CuII‐Dp44mT with thiols leading to their depletion or inhibition was proposed to be involved in this activity. Indeed, CuII‐Dp44mT can catalyze the oxidation of thiols although with slow kinetics. The present work aims to obtain insights into the catalytic activity and selectivity of CuII‐Dp44mT toward the oxidation of different biologically relevant thiols. Reduced glutathione (GSH), L‐cysteine (Cys), N‐acetylcysteine (NAC), D‐penicillamine (D‐Pen), and the two model proteins glutaredoxin (Grx) and thioredoxin (Trx) were investigated. CuII‐Dp44mT catalyzed the oxidation of these thiols with different kinetics, with rates in the following order D‐Pen>Cys≫NAC>GSH and Trx>Grx. CuII‐Dp44mT was more efficient than CuII chloride for the oxidation of NAC and GSH, but not D‐Pen and Cys. In mixtures of biologically relevant concentrations of GSH and either Cys, Trx, or Grx, the oxidation kinetics and spectral properties were similar to that of GSH alone, indicating that the interaction of these thiols with CuII‐Dp44mT is dominated by GSH. Hence GSH could protect other thiols against potential deleterious oxidation by CuII‐Dp44mT. [ABSTRACT FROM AUTHOR]

BiVO 4 photoanode shows severe recombination of photogenerated carriers, which limits its water oxidation performance for photoelectrochemical (PEC) water splitting. In this paper, the surface of BiVO 4 photoanode was modified through the coupling of phosphotungstic acid (H 3 O 40 PW 12 ·xH 2 O, denotes as PWO) with CoOOH to address such drawbacks. At 1.23 V RHE , the photocurrent density of BiVO 4 /PWO/CoOOH photoanode reaches 2.80 mA/cm2, which is 2.59-fold that of bare BiVO 4 photoanode. Moreover, the initial onset potential of BiVO 4 /PWO/CoOOH photoanode is also negatively decreased by 270 mV than that of bare BiVO 4 photoanode. Detailed structural and electrochemical characterizations demonstrate that the decoration of PWO serves as an intermediate layer to promote the transport of holes from BiVO 4 to CoOOH, while the deposition of CoOOH acts as a protective layer as well as cocatalyst to reduce the photocorrosion and improve the PEC activities of BiVO 4. The synergistic coupling of PWO and CoOOH not only makes efficient bulk and surface charge separation, but also takes full advantage of photo-generated holes on the surface, which accelerates water oxidation kinetics, ultimately achieving an improvement in PEC water oxidation. PWO and CoOOH, which widens the range of light absorption and effectively enhances the capacity of light absorption, can therefore induce BiVO 4 to produce more photogenerated charge. Meanwhile, CoOOH facilitates the kinetics of water oxidation. The synergistic effect of PWO and CoOOH improves the PEC performance of BiVO 4. [Display omitted] • BiVO 4 /PWO/CoOOH composite photoanode is reasonably designed and synthesized. • BiVO 4 /PWO/CoOOH photoanode shows excellent stability for PEC. • BiVO 4 /PWO/CoOOH electrode exhibited a high PCD of 2.8 mA/cm2 at 1.23 V RHE. • Synergistic effects of PWO and CoOOH deposition improved the performance. [ABSTRACT FROM AUTHOR]

This study investigates the cyclic oxidation behaviour of a thermal barrier coating (TBC) system applied to Inconel 718 alloy substrates. The TBC comprises a NiCr bond coat and a YSZ top coat, applied using the air plasma spray method. Cyclic oxidation studies involve subjecting the coated samples to repeated heating and cooling cycles, with mass gain measurements taken after each cycle. Vibrational modes and surface morphology are analysed before and after oxidation. Results reveal a gradual increase in mass gain up to the 4th cycle, attributed to interface bonding and diffusion-limited growth. Thermal cycling induces stresses, leading to micro cracking and accelerated oxidation. Oxidation kinetics follows both parabolic and linear laws, with rates decreasing over cycles. Kl values consistently exceed Kp, indicating faster linear growth. The study enhances understanding of TBC behaviour under cyclic oxidation conditions, critical for improving durability in practical applications. [ABSTRACT FROM AUTHOR]

The high-temperature oxidation behavior of a novel γ′-strengthened CoNi-base superalloy was investigated by isothermal oxidation in air at 700 °C and 900 °C. The results show that the superalloy formed a multilayered oxide scale at the two temperatures, exhibiting parabolic oxidation kinetics. Theoretical calculations suggest that the alloy Al content was insufficient to form a protective alumina scale and elevating temperature was beneficial for reducing the critical Al concentrations required for alumina scale formation. In agreement with the predications, a discontinuous alumina band was developed at the oxidation front as the temperature was increased from 700 to 900 °C. [ABSTRACT FROM AUTHOR]

Kinetics of oxidation of malic acid by tetraphenylphosphonium chlorochoramate has been investigated in 50% acetic acid and 50% water medium. Tetraphenylphosphonium chlorochoramate, malic acid, and hydrogen ion concentrations are all first order for the reaction. Oxidation rates rises with a reduction in the solvent's dielectric constant. It denotes the interaction of ions and dipoles during the rate-determining step. By increasing the quantity of sodium perchlorate, there is no influence on the rate constant. No polymerisation with acrylonitrile occurs, and it is proved that there are no free radicals. At four different temperatures, the reaction's rate has been measured. Calculations of thermodynamic parameters have been made. The kinetics data have led to the suggestion of a suitable mechanism. [ABSTRACT FROM AUTHOR]

Tris(3-hydroxypropyl)phosphine (THPP) was shown to be a more powerful reductant than tris(2-carboxyethyl)phosphine (TCEP), but its oxidation kinetics and mechanisms were scarcely investigated. The reduction of single electron oxidant [IrCl6]2− by THPP was thus investigated comparatively and shown to follow overall second-order kinetics. The established logk′ versus pH profiles for THPP and TCEP were different, where k′ is the observed second-order rate constant. THPP was oxidized to (HOCH2CH2CH2)3PO, confirmed by 1H NMR spectroscopy, which is in line with the determined stoichiometry. On the other hand, the proposed reaction mechanism is similar to that suggested for the TCEP reaction. The reactivity of THPP was derived, enabling a reactivity comparison with TCEP at physiological pH. Surprisingly, the measured activation parameters for the reduction of [IrCl6]2− by P(CH2CH2CH2OH)3 and P(CH2CH2CO2−)3 were essentially identical, providing information on the transition state and on the electron transfer mode. This work also defines the pKa value of THPP under well-defined conditions (pKa = 6.97 ± 0.05 at 25.0 °C and 1.0 M ionic strength) as derived by the kinetic approach. [ABSTRACT FROM AUTHOR]

Ceramics exhibit stochastic fracture behavior due to internal and surface defects, thereby limiting their practical use. To address this issue, a combined method of 'self-crack-healing' and 'proof testing' has been proposed. However, to efficiently implement the method, a numerical analysis is required for preliminary investigation. This study establishes a finite element analysis methodology that enables the prediction of both strength recovery due to crack healing and the scatter of strength due to microstructural features. We determine the dependence of the scatter of the three-point bending strength on the healing conditions using the Weibull distribution and demonstrate the applicability of the proposed analysis method to proof tests. Results revealed that the proposed methodology can estimate the healing conditions and proof stresses by obtaining the microstructural information and oxidation kinetics parameters of the ceramic components in advance. • A method for predicting the strength recovery and scatter in ceramics was developed. • Finite element analysis was used coupling "crack healing" and "proof testing". • Fracture from internal defects becomes dominant as surface cracks heal. • The number of high-stress-enduring specimens increased with the healing time. • Virtual experiment verified the method feasibility and ceramics structural reliability. [ABSTRACT FROM AUTHOR]

Herein, the effects of Gd2O3 on the laser cladding NiCoCrAlYTa coatings in terms of microstructure, phase structures, high temperature oxidation behaviors were investigated. The results showed that the addition of Gd2O3 changed the composition of coating phases, promoted homogeneous phase distribution, reduced porosity and improved coating density. During oxidation at 1100 °C for 150 h, the increase in the content of added Gd2O3 (at mass fractions of 0, 0.5, 1, 2, 5 and 10%) exhibited an initial inhibitory and then increased effect on the weight-gain rate of the coatings. Overall, 1% Gd2O3 addition resulted in the greatest improvement in the oxidation resistance of the coatings, with 49.58% decreases in oxidation kinetic constants, respectively, compared with those of unmodified coatings. However, at a Gd2O3 content of 10%, the thermally grown oxide on the coating surface exhibited large flaking areas. The high-temperature oxidation kinetic parameters of the coatings exhibited an inverted parabolic form with increasing Gd2O3 content. The higher Gd2O3 content led to the formation of excessive oxygen diffusion channels along grain boundaries, which is the reason for the decrease in the anti-oxidant performance of the coating. [ABSTRACT FROM AUTHOR]

In the present study, a Cr–Si‐alloyed coating‐free press‐hardened steel (CF–PHS) is investigated and compared with the conventional 22MnB5 steel through a 60 min oxidation experiment at 1000–1200 °C. Compared to the 22MnB5 steel, the CF–PHS exhibits lower weight gain at 1000–1150 °C but a higher weight gain at 1200 °C. In the results, using scanning electron microscopy, energy‐dispersive spectroscopy, and X‐ray diffraction, it is revealed that the outer oxide layer of the CF–PHS consisted of Fe2O3 and Fe3O4, while its inner oxide layer is enriched with FeCr2O4 and Fe2SiO4—crucial for the oxidation resistance of the CF–PHS. The outer oxide layer of 22MnB5 comprises Fe2O3, Fe3O4, and FeO, while the inner layer contains low concentrations of Cr and Si. The mechanism of superior high‐temperature oxidation resistance of CF–PHS compared to 22MnB5 at 1000–1150 °C reveals that the existence of FeCr2O4 and Fe2SiO4 inhibits the diffusion of Fe2+ and O2−, effectively hindering the oxidation progress. Moreover, the oxidation resistance of the CF–PHS at 1200 °C deteriorates owing to the melting of Fe2SiO4 at 1200 °C, which significantly accelerates the diffusion of Fe2+ and O2−, thus exacerbating the oxidation of CF–PHS. [ABSTRACT FROM AUTHOR]

The present study examines the high-temperature (500–800 °C) oxidation behavior of Fe-10Cr-(3,5) Al alloys and studies the effect of nanocrystalline structure and Al content on their resistance to oxidation. The nanocrystalline (NC) alloy powder was synthesized via planetary ball milling. The prepared NC alloy powder was consolidated using spark plasma sintering to form NC alloys. Subsequently, an annealing of the NC alloys was performed to transform them into microcrystalline (MC) alloys. It was observed that the NC alloys exhibit superior resistance to oxidation compared to their MC counterparts at high temperatures. The superior resistance to oxidation of the NC alloys is attributed to their considerably finer grain size, which enhances the diffusion of those elements to the metal–oxide interface that forms the protective oxide layer. Conversely, the coarser grain size in MC alloys limits the diffusion of the oxide-forming components. Furthermore, the Fe-10Cr-5Al alloy showed greater resistance to oxidation than the Fe-10Cr-3Al alloy. [ABSTRACT FROM AUTHOR]

This project studies the influence of different grain sizes of Ni-based Fe-33Ni-19Cr alloy obtained from heat treatment procedure on high temperature isothermal oxidation. Heat treatment procedure was carried out at two different temperatures, namely 1000°C and 1200°C for 3 hours of soaking time, followed by quenching in the water. These samples are denoted as T1000 and T1200. The heat-treated Ni-based Fe-33Ni-19Cr alloy was subjected to an isothermal oxidation test at 950°C for 150 hours exposure. Oxidized heat-treated alloys were tested in terms of oxidation kinetics, phase analysis and surface morphology of oxidized samples. Oxidation kinetics were determine based on weight change per surface area as a function of exposure time. Phase analysis was determined using the x-ray diffraction (XRD) technique and surface morphology of oxidized samples was characterized using a scanning electron microscope (SEM). As a result, the heat treatment procedure shows varying grain sizes. The higher the heat treatment temperature, shows an increase in grain size with a decrease in hardness value. The oxidation kinetics for both heat-treated samples showed an increment pattern of weight change and followed a parabolic rate law. The oxidized T1000 sample recorded the lowest parabolic rate constant of 3.12×10-8 mg2cm-4s-1, indicating a low oxidation rate, thus having good oxidation resistance. Phase analysis from the XRD technique recorded several oxide phases consisting of Cr2O3, MnCr2O4, and (Ti0.97Cr0.03)O2 oxide phases. In addition, a uniform oxide layer is formed on the oxidized T1000 sample, indicating good oxide scale adhesion, thereby improving the protective oxide behavior. [ABSTRACT FROM AUTHOR]

The effect of the electro-Fenton process depends on the ability of the cathode material to produce H2O2, a primary oxidizing agent that is responsible for destroying organic pollutants. The study aimed at the impact of various cathode materials, including carbon felt, carbon graphite, and stainless steel, as well as current density on the electrochemical oxidation of pefloxacin (PEF) in water. The electro- -Fenton technique was applied for the first time on the PEF employing various cathodes with a platinum anode. HPLC and LC-(MS-MS) studies have been utilized to determine intermediate compounds. Using ion chromatography, inorganic ions released in the solution as a final stage of the mineralizing process were determined. Finally, we assessed the viability of fusing the biological process with the electro-Fenton one. As a result, PEF-contaminated water can be treated effectively and cheaply. [ABSTRACT FROM AUTHOR]

In situ combustion (ISC), an efficient and economical method for enhancing heavy oil recovery in high-pressure, high-viscosity, and thermally challenged reservoirs, relies on the kinetics of crude oil oxidation. Despite an increased focus on kinetic models, there is a gap in understanding how oxidation kinetic parameters impact ISC effectiveness in heavy oil reservoirs. This study addresses this by selecting heavy oil samples from the G Block in the Liaohe oilfield and the M Block in the Huabei oilfield and conducting ramped temperature oxidation (RTO), pressure differential scanning calorimetry (PDSC), and thermogravimetric analysis (TGA) experiments. RTO detailed the thermal conversion process, categorizing oxidation into low-temperature oxidation (LTO), fuel deposition (FD), and high-temperature oxidation (HTO) stages. PDSC and TGA provided thermal characteristics and kinetic parameters. The feasibility of fire flooding was evaluated. Using CMG-STARS, an ISC model was established to analyze the impact of kinetic parameter changes. Activation energy significantly affected coke combustion, while the pre-exponential factor had a notable impact on cracking reactions. The recommended values for activation energy and the pre-exponential factor are provided. This study not only guides fire flooding experiments but also supports field engineering practices, particularly for in situ combustion in heavy oil reservoirs. [ABSTRACT FROM AUTHOR]

To promote interfacial charge transfer process and accelerate surface water oxidation reaction kinetics for photoelectrochemical (PEC) water splitting over n‐type Silicon (n‐Si) based photoanodes, herein, starting with surface stabilized n‐Si/CoOx, a NiOx/NiFeOOH composite overlayer was coated by atomic layer deposition and spray coating to fabricate the multilayer structured n‐Si/CoOx/NiOx/NiFeOOH photoanode. Encouragingly, the obtained n‐Si/CoOx/NiOx/NiFeOOH photoanode exhibits much increased PEC activity for water splitting, with onset potential cathodically shifted to ~0.96 V vs. RHE and photocurrent density increased to 22.6 mA cm−2 at 1.23 V vs. RHE for OER, as compared to n‐Si/CoOx, even significantly surpassing the counterpart n‐Si/CoOx/NiOx/FeOOH and n‐Si/CoOx/NiOx/NiOOH photoanodes. Photophysical and electrochemical characterizations evidence that the deposited CoOx/NiOx/NiFeOOH composite overlayer would create large band bending and strong built‐in electric field at the introduced cascading interfaces, thereby producing a large photovoltage of 650 mV to efficiently accelerate charge transfer from the n‐Si substrate to the electrolyte for water oxidation. Furthermore, the surface oxygen vacancy enriched NiFeOOH overlayer could effectively catalyze the water oxidation reaction by thermodynamically reducing the energy barrier of rate determining step for OER. [ABSTRACT FROM AUTHOR]

The isothermal oxidation experiments of tungsten carbides (WC) were carried out at levels of inequality in relative humidity (RH) levels and below 200 °C. Evaluated resistivity fluctuations and structural transformations during the low-temperature corrosion process were detected. In this paper, we present a detailed investigation into the resistivity behavior of WC under varying humidity conditions. Our innovative approach enabled us to witness a rapid decrease in resistivity under conditions of 85 % RH and 85 °C, from 0.00374 Ω-cm to 0.00177 Ω-cm, followed by a stable linear increase after 0.7 h at a constant rate of 0.000924 Ω-cm/h. Notably, a clear correlation between humidity levels and resistance change rates was found, where higher humidity led to faster resistivity changes. In sharp contrast, a resistivity change rate of less than 5 % under the conditions of water and oxygen independently was observed. The low-temperature oxidation mechanism of WC was described by XRD and XPS spectra. Moreover, the Nernst-Einstein equation and Wagner's model are used to establish the relationship between resistivity and oxidation degree for analyzing and predicting the reaction kinetics and oxidation behavior, indicating that the oxidation degree of WC increased logarithmically with oxidation time. [ABSTRACT FROM AUTHOR]

In this study, SiBCN ceramics with a structure of three-dimensional PDCs-SBCN network structure coated MA-SiBCN (MA@PDCs-SiBCN) were fabricated, which significantly improved the sintering activity and oxidation performance. The effect of MA@PDCs-SiBCN structure on oxidation behaviors and kinetics of oxide layer growth of the SiBCN ceramics at 1500 ℃ was investigated, indicating that the significantly improved oxidation resistance is attributed to the different heterogeneous oxidation behaviors, especially in the initial stage. Therefore, the heterogeneous oxidation behaviors and kinetic laws of different phases in MA@PDCs-SiBCN ceramics at different temperature ranges and their effects on structural evolution and oxide layer composition were analyzed by comparison with the MA-SiBCN ceramics. The significantly improved oxidation resistance of MA@PDCs-SiBCN ceramics should be attributed to the inhibition of MA@PDCs-SiBCN structure to heterogeneous oxidation, especially the consumption of t-C, and different oxide layer composition generated from microcrystalline structure rather than nanocapsule-like crystalline structure. [Display omitted] [ABSTRACT FROM AUTHOR]

The oxidation behavior of a novel Ni-based single-crystal 4774DD1 superalloy for industrial gas turbine applications was investigated by the isothermal oxidation at 980 ºC and discontinuous oxidation weight gain methods. The phase constitution and morphology of surface oxides and the characteristics of the crosssection oxide film were analyzed by XRD, SEM and EDS. Results show that the oxidation kinetics of the 4774DD1 superalloy follows the cubic law, indicating its weak oxidation resistance at this temperature. As the oxidation time increases, the composition of the oxide film evolves as following: One layer consisting of a bottom Al2O3 sublayer and an upper (Al2O3+NiO) mixture sublayer after oxidized for 25 h. Then, two layers composed of an outermost small NiO discontinuous grain layer and an internal layer for 75 h. This internal layer is consisted of the bottom Al2O3 sublayer, an intermediate narrow CrTaO4 sublayer, and an upper (Al2O3+NiO) mixture sublayer. Also two layers comprising an outermost relative continuous NiO layer with large grain size and an internal layer as the oxidation time increases to 125 h. This internal layer is composed of the upper (Al2O3+NiO) mixture sublayer, an intermediate continuous (CrTaO4+NiWO4) mixture sublayer, and a bottom Al2O3 sublayer. Finally, three layers consisting of an outermost (NiAl2O4+NiCr2O4) mixture layer, an intermediate (CrTaO4+NiWO4) mixture layer, and a bottom Al2O3 layer for 200 h. [ABSTRACT FROM AUTHOR]

A high amount of TiO2 in the blast‐furnace slag during the smelting of vanadium‐bearing titanomagnetite can generate TiC, resulting in poor metallurgical properties of the slag. Based on this background, the oxidation of TiC by CO2 in the blast‐furnace gas and its kinetics are discussed in this article, to achieve control over the generation of TiC. The results show that TiC is oxidized by the CO2 in the blast‐furnace gas, generating TiO2. The oxidation rate increases upon increasing the oxidation temperature, at all oxidation stages in the same atmosphere. At a given temperature, a higher volume fraction of CO2 in the atmosphere is conducive to the faster oxidation of TiC. The oxidation of TiC is mainly controlled by the interfacial chemical reaction at the initial stage and by the mixed control of the interfacial chemical reaction and internal diffusion at a later stage. [ABSTRACT FROM AUTHOR]

This study investigates the effect of TiO2 on the oxidation kinetic mechanism of iron ore concentrate under nonisothermal conditions. Based on the fact that iron‐containing materials are mainly smelted in the form of pellets, the microstructure evolution of pellets with different TiO2 additions during oxidation is studied to verify the accuracy of the kinetic analysis results. The results show that the reaction model is the mechanism describing oxidation of iron ore concentrate under different TiO2 additions at stages I and II. The increase of TiO2 increases E and worsens the oxidation kinetic conditions at stages I and II. This phenomenon is caused by the Fe–Ti solid solution embedded in the hematite particles hindering the recrystallization and large‐scale crystal bridge connection of hematite. The fluctuation amplitude of apparent activation energy (E) at stages I and II is 23.6112 and 19.508 kJ mol−1, respectively. Furthermore, the mechanism of stage III corresponds to the diffusion model, and the increase of TiO2 decreases E and improves the oxidation kinetic conditions. It is due to the loose structure of pellets with the increase of TiO2, facilitating the internal diffusion of reaction gases. The fluctuation amplitude of E is 5.07 kJ mol−1 at stage III. [ABSTRACT FROM AUTHOR]

A change in the number of micelles was found to affect the kinetics of oxygen absorption of the entire microheterogeneous system, primarily the type of chain termination (310 K) as evidenced by the results of the study of the oxidation of methyl linoleate (LH) in cetyltrimethylammonium bromide (CTAB) micelles. Mixed micelles are formed, and the probability of isomerization and decomposition of peroxyl radicals of the substrate (LO2•) with the formation of HO2• increases. Given the hydrophilic character of HO2•, it can be assumed that these radicals diffuse to the aqueous phase to a higher extent, whereas the disproportionation in the organic phase is less pronounced. This leads to a decrease in the chain termination rate, which is kinetically described as a formally linear chain termination. As a result, the LH oxidation rate in CTAB micelles increases. [ABSTRACT FROM AUTHOR]

Owing to the intrinsically sluggish kinetics of urea oxidation reaction (UOR) involving a six‐electron transfer process, developing efficient UOR electrocatalyst is a great challenge remained to be overwhelmed. Herein, by taking advantage of 2‐Methylimidazole, of which is a kind of alkali in water and owns strong coordination ability to Co2+ in methanol, trace Co (1.0 mol%) addition was found to induce defect engineering on α‐Ni(OH)2 in a dual‐solvent system of water and methanol. Physical characterization results revealed that the synthesized electrocatalyst (WM‐Ni0.99Co0.01(OH)2) was a kind of defective nanosheet with thickness around 5–6 nm, attributing to the synergistic effect of Co doping and defect engineering, its electron structure was finely altered, and its specific surface area was tremendously enlarged from 68 to 172.3 m2 g−1. With all these merits, its overpotential to drive 10 mA cm−2 was reduced by 110 mV. Besides, the interfacial behavior of UOR was also well deciphered by operando electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Catalytic wet oxidation (CWO) of aqueous effluents rich in organic compounds is a very promising technology for the treatment of liquid wastes from biomass conversion processes. CWO reactions occur through the formation of free radical species, produced in the presence of an oxidant, which act on organic contaminates in the effluent. Although the reaction is well known, there exists a lack of affordable catalysts to conduct this process at the lower temperatures and pressures in novel bioenergy processes. This study assessed the catalytic effect of nitrogen-doped chars as such an option. Phenol in aqueous solution was used as a model waste effluent. Treatment was conducted at moderate temperatures (190 to 260 °C), oxygen partial pressure of 1 MPa, and reaction times of 15, 30, and 45 min in stainless steel and glass-lined tube reactors. High pressure liquid chromatography (HPLC) analyses of the products quantified phenol and by-product concentrations used in the calculation of reaction activation energy. The char catalyst was studied by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) in order to gain insight into its structure and surface composition. The results indicate that nitrogen-doped char catalysts accelerate the oxidation of phenol by decreasing its reaction activation energy from 82.2 kJ/mol (non-catalyzed) to 40.4 kJ/mol (catalyzed). An analysis from first principles using density functional theory (DFT) was conducted to ascertain which N functional group has the most significant impact on free radical formation in the presence of oxygen. Among all the N functional groups studied, the dipyridinic functional groups showed the most promising characteristics to facilitate the formation of hydroxyl free radicals. [ABSTRACT FROM AUTHOR]

The oxidation of the lead alloy SSu3 with lithium in air under isothermal conditions was studied by thermogravimetry while continuously recording the sample mass for 1 h at temperatures of 473, 523, and 573 K. Kinetic curves of oxidation of the SSu3 alloy with lithium were constructed based on the experimental data. The dependences of the specific weight increment on the amount of the alloying additive and temperature were determined from the curves. A lithium addition of up to 1.0 wt % increases the rate of oxidation of the lead alloy, which is accompanied by a decrease in the apparent activation energy of oxidation. Quadratic kinetic curves of alloy oxidation were constructed. The mechanism of oxidation of alloys was established. The oxidation of alloys in the given temperature range of 473–573 K obeys the hyperbolic law , where n = 1–4. [ABSTRACT FROM AUTHOR]

This study conducts a detailed analysis of high-temperature oxidation and microstructural evolution in two high-alloy Fe-based alloys, each characterized by a high-volume fraction of carbides but differentiated by their matrices − body-centered cubic (BCC) and face-centered cubic (FCC), which was achieved by the addition of nickel. By investigating the intricate interplay of factors such as phase composition, nickel content, and the presence of carbides, this research aims to elucidate the diverse oxidation kinetics and underlying mechanisms specific to each alloy type. Results show that the BCC alloy exhibits slower oxidation kinetics compared to its FCC counterpart, suggesting better performance in high-temperature environments. Moreover, while both alloys develop strong adhesive oxide scales primarily composed of Cr2O3, the FCC alloy experiences more pronounced scale spallation and cracking. A faster progression of decarburization was observed in the BCC alloy. This comprehensive comparison highlights how variations in matrix structure, along with nickel content and carbide behavior, critically influence oxidation kinetics, scale adhesion, and the overall integrity of oxide scales. Understanding these nuanced interactions is crucial for designing high-performance alloys tailored for extreme operating conditions.

The effect of a constant magnetic field on the adrenaline oxidation was studied, and the oxidation kinetics was analyzed. The relationships found suggest the leading role of the superoxide radical. The magnetic field increases the disproportionation rate of superoxide radicals, decreasing their concentration and thus decreasing the oxidation rate. Introduction of superoxide dismutase and an increase in its amount lead to a decrease in the rate of the adrenaline consumption via oxidation. The exposure to a magnetic field in the presence of superoxide dismutase leads to still more pronounced reaction deceleration. [ABSTRACT FROM AUTHOR]

About 40 years ago, the U.S. Bureau of Mines developed a simple mine water treatment approach that appears to have largely been forgotten. The in-line aeration and treatment system or more simply, the in-line system (ILS), was designed to treat acid mine drainage (AMD) within existing AMD pipelines. The initial device consisted of two inexpensive off-the-shelf components, a jet pump, which entrains air by Venturi action, and a static mixer, which induces turbulent flow. The system had no moving parts, could easily be assembled on site, and was designed to use the pressure generated by an existing mine water discharge pump. In pilot-scale and full-scale field tests, it was shown to be effective for treating both coal and metal mine drainage, on the surface and underground. Moreover, the iron oxidation kinetics and efficiency of lime consumption far exceeded that which occurred in normal active treatment plants. [ABSTRACT FROM AUTHOR]

The oxidation behavior and kinetics of (Zr, Ti)(C, N)–SiC ceramics subjected to a temperature of 850 °C-950 °C (typical operating temperatures range of Generation-IV nuclear reactors) for 1–4 h are investigated via X-ray diffraction, scanning electron microscopy, and weight gain testing. The results show that the microstructures of the ceramics after oxidation comprises primarily of m-(Zr, Ti)O2, c-(Zr, Ti)O2, and SiO2. After adding Si, the oxidation layer appears as a two-layer structure with both external and internal layers. The oxidation order of (Zr, Ti)(C, N)–SiC ceramics at 850 °C-950 °C is ZrSi > (Zr, Ti)(C, N) > SiC. Unoxidized SiC forms a “core-shell” structure with a dense external layer of SiO2. The dual effect of small SiO2 particles occupying cracks and the “core-shell” structure of SiC–SiO2 withstanding stresses can inhibit the propagation of cracks and reduce the porosity of the oxide layer. The oxidation of Z5T and Z5T5S exhibits linear oxidation kinetics, whereas the oxidation of Z5T10S and Z5T20S results in quasi-parabolic oxidation. By adding Si, the oxidation activation energy of Z5T20S (with the addition of 20 mol% Si) increases by 174 % compared to that of Z5T ceramic, thus improving the oxidation resistance of (Zr, Ti)(C, N)-based ceramics at 850 °C-950 °C.

The thermal shock protection of SiC/SiC composites have become pivotal challenges in promoting their application in a heat field environment. This study presents a borosilicate glass (BSG) coating was fabricated successively by slurry brushing-sintering for SiC/SiC composites. The results show that the coated SiC/SiC composites exhibit excellent thermal protective resistance with a rather light mass change (

Glutaredoxins catalyze the reduction of disulfides and are key players in redox metabolism and regulation. While important insights were gained regarding the reduction of glutathione disulfide substrates, the mechanism of non-glutathione disulfide reduction remains highly debated. Here we determined the rate constants for the individual redox reactions between PfGrx, a model glutaredoxin from Plasmodium falciparum, and redox-sensitive green fluorescent protein 2 (roGFP2), a model substrate and versatile tool for intracellular redox measurements. We show that the PfGrx-catalyzed oxidation of roGFP2 occurs via a monothiol mechanism and is up to three orders of magnitude faster when roGFP2 and PfGrx are fused. The oxidation kinetics of roGFP2-PfGrx fusion constructs reflect at physiological GSSG concentrations the glutathionylation kinetics of the glutaredoxin moiety, thus allowing intracellular structure-function analysis. Reduction of the roGFP2 disulfide occurs via a monothiol mechanism and involves a ternary complex with GSH and PfGrx. Our study provides the mechanistic basis for understanding roGFP2 redox sensing and challenges previous mechanisms for protein disulfide reduction. Fusion proteins between roGFP2 and glutaredoxins are used for intracellular redox measurements. Here, the authors determined all rate constants of the reaction cycle for roGFP2 measurements and identified an alternative glutaredoxin mechanism. [ABSTRACT FROM AUTHOR]

Competing double-exchange and super-exchange interactions yield rich chemistry for understanding robust oxygen evolution activity in Ru-doped lanthanum strontium manganite, with an overpotential of 300 mV at 10 mA cm−2 and a Tafel slope of 110 mV dec−1. Favourable redox potentials of Mn3+/Mn4+ and Ru4+/Ru5+ lead to improved charge transfer kinetics for OER activity. [ABSTRACT FROM AUTHOR]

Stable solid electrolytes are essential to high-safety and high-energy-density lithium batteries, especially for applications with high-voltage cathodes. In such conditions, solid electrolytes may experience severe oxidation, decomposition, and deactivation during charging at high voltages, leading to inadequate cycling performance and even cell failure. Here, we address the high-voltage limitation of halide solid electrolytes by introducing local lattice distortion to confine the distribution of Cl−, which effectively curbs kinetics of their oxidation. The confinement is realized by substituting In with multiple elements in Li3InCl6 to give a high-entropy Li2.75Y0.16Er0.16Yb0.16In0.25Zr0.25Cl6. Meanwhile, the lattice distortion promotes longer Li-Cl bonds, facilitating favorable activation of Li+. Our results show that this high-entropy halide electrolyte boosts the cycle stability of all-solid-state battery by 250% improvement over 500 cycles. In particular, the cell provides a higher discharge capacity of 185 mAh g−1 by increasing the charge cut-off voltage to 4.6 V at a small current rate of 0.2 C, which is more challenging to electrolytes|cathode stability. These findings deepen our understanding of high-entropy materials, advancing their use in energy-related applications. Solid electrolytes play a crucial role as ion conductors and separator between electrodes in all-solid-state batteries. Here, the authors report a high-entropy halide solid electrolyte, which reveals the structure evolution with the increasing configurational entropy and improves the high-voltage stability. [ABSTRACT FROM AUTHOR]

Rechargeable Li−Cl2 battery is a promising high energy density battery system. However, reasonable cycle life could only be achieved under low specific capacities due to the sluggish oxidation of LiCl to Cl2. Herein, we propose an amine‐functionalized covalent organic framework (COF) with catalytic activity, namely COF−NH2, that significantly decreases the oxidation barrier of LiCl and accelerates the oxidation kinetics of LiCl in Li−Cl2 cell. The resulting Li−Cl2 cell using COF−NH2 (Li−Cl2@COF−NH2) simultaneously exhibits low overpotential, ultrahigh discharge capacity up to 3500 mAh/g and a promoted utilization ratio of deposited LiCl at the first cycle (UR−LiCl) of 81.4 %, which is one of the highest reported values to date. Furthermore, the Li−Cl2@COF−NH2 cell could be stably cycled for over 200 cycles when operating at a capacity of 2000 mAh/g at −20 °C with a Coulombic efficiency (CE) of ≈100 % and a discharge plateau of 3.5 V. Our superior Li−Cl2 batteries enabled by organocatalyst enlighten an arena towards high‐energy storage applications. [ABSTRACT FROM AUTHOR]

The oxidation characteristics and spontaneous combustion (SC) tendency of raw long-flame coal (RC), water-soaked 200-day coal (S200), pre-oxidized water-soaked coal at 200 °C (O200S200), and pre-oxidized soaked coal at 300 °C (O300S200) in an oxygen-poor environment were investigated using a programmed warming system. The results show that pre-oxidation water-soaked treatment (PWT) promotes the coal-oxygen complex reaction and increases the rate of coal oxygen consumption (OCR) and the rate of carbon and oxygen compound production. The rate of CO and CO2 production of the water-soaked (WS) coal increased by 0.329 mol·(cm3·s)−1 and 0.922 mol·(cm3·s)−1, respectively, compared with that of the original coal sample. PWT reduces the activation energy of coal in the low-temperature oxidation stage (the maximum difference can be up to 110.99 kJ/mol) and enhances the oxidizing and heat-releasing capacity. There was a synergistic effect between the pre-oxidation (PO) and WS treatment, and the lowest comprehensive determination index of the SC propensity of coal in O200S200 samples was 831.92 which was 4.72 lower than that of RC samples, presenting a more SC tendency. Low oxygen concentration has an inhibitory effect on the oxidation characteristic parameters of coal, and the apparent activation energy of the low-temperature oxidation stage of pre-oxidized water-soaked coal (PWC) increased to 206.418 kJ/mol at 3% oxygen concentration. The lower the oxygen concentration of the anoxic environment, the lower the risk of SC of the coal samples. The results of the study can provide theoretical guidance for the identification and prevention of SC disasters in coal seams with shallow burial and close spacing. [ABSTRACT FROM AUTHOR]