This study uses density functional theory (DFT) to investigate the selective hydrogenation of acetylene (C2H2) on palladium-based catalysts with core@shell (M13@Pd42) and Crown-Jewel (CJ-M43Pd12) structures. The influence of Cu, Ag, and Au dopants are evaluated to guide the design of highly efficient Pd-based catalysts for converting acetylene to ethylene (C2H4). The calculation reveals that the Crown-Jewel structured Cu43Pd12 (CJ-Cu43Pd12) catalyst exhibits superior activity and selectivity for ethylene production compared to the core@shell structured Cu13@Pd42 and the pure Pd55 catalysts. Electronic structure analysis reveals that the Cu-Pd interaction and electron transfer from Cu to Pd enhance performance in the CJ-Cu43Pd12 catalyst. The findings highlight the significance of geometrical and electronic considerations in the design of catalytic systems for acetylene hydrogenation. These results establish an atomistic theoretical framework for Pd-efficient acetylene semihydrogenation catalysts, demonstrating that the Crown-Jewel geometry can integrate Pd-site isolation and Cu to Pd electronic modulation to balance C2H2 activation, C2H4 desorption, and Pd atom utilization efficiency.

The volatilization and distribution behavior of gallium (Ga) from coal gasification slag (CGS) roasted with barium chloride dihydrate were investigated using leaching and solid characterizations including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), thermogravimetry–differential scanning calorimetry (TG-DSC), and X-ray absorption fine structure (XAFS). The Ga content in roasting sample exhibited an increasing trend from the bottom to the top zone. When the roasting time was 6 h, the Ga content in the top zone reached a maximum value of 105.66 μg/g, which was around 4 times the theoretically calculated initial Ga content (25.97 μg/g) in the material before roasting. Combined analysis of the sequential extraction procedure and EXAFS results revealed that the primary mode of occurrence for Ga was in the form of oxides. In addition, the volatilization ratio of Ga was only 10.53% after roasting for 8 h, confirming that Ga volatilization was a dynamic process involving chlorination, upward migration, conversion to non-volatile Ga, and further volatilization. The enrichment of Ga in samples from the top zone was attributed to the formation of non-volatile Ga-containing oxides, resulted from the further reaction of volatile gallium chloride species with oxide phases.

Natural flake graphite exhibits superior oxidation and corrosion resistance among carbon sources, but its hydrophobicity and poor dispersion limit its use in refractory castables, increasing water demand and degrading high-temperature performance. In this study, AlOOH nanofiber-coated graphite (G@AlOOH) was prepared via a hydrothermal method to address these issues. Monte Carlo simulation was employed to reveal the growth mechanism of nanofibers on graphite surfaces. The uniform AlOOH coating creates a rough structure and introduces hydrophilic hydroxyl groups, reducing the water contact angle from 95.2° to 26.0°. Rheological and settling tests confirm improved dispersion and reduced viscosity. Consequently, Al2O3-SiC-C castables with G@AlOOH show lower water demand, reduced porosity, higher bulk density, and enhanced thermal shock resistance and slag corrosion resistance.

Constrained by the low grade and poor floatability of the run-of-mine ore, the beneficiation of porphyry-type copper-molybdenum sulfide ores generates large quantities of molybdenum tailings, leading to significant environmental risks and resource losses and necessitating urgent recovery and reutilization. In this study, a representative sample of molybdenum tailings with a Mo grade of 0.354% was investigated to analyze its process mineralogy. The results show that molybdenite predominantly exists as fine, flaky particles intimately intergrown with quartz, pyrite, and aluminosilicate minerals, exhibiting an extremely low degree of liberation and an overall ultrafine particle size. Laboratory flotation tests show that the flotation kinetics conform to a first-order model; however, a considerable amount of molybdenum remains in the tailings, indicating that the mineralization process needs to be intensified. Through structural optimization and confined-space design, a vortex-based mineralization reactor was developed. Computational fluid dynamics simulations demonstrate that the mineralizer can generate flow fields with high turbulence intensity and dissipation rates and can induce high-energy, small-scale micro-vortices. On this basis, a semi-industrial rougher flotation system was established by coupling the developed mineralizer with a flotation column. Under optimized operating conditions, namely a feed pressure of 0.06 MPa and an impeller frequency of 20 Hz, single-stage treatment of the tailings produced molybdenum concentrates with a grade of 1.90% and a recovery of 81.29%, while the Mo grade of the tailings was reduced to 0.08%. The results are markedly superior to those obtained using a conventional laboratory flotation cell, demonstrating a substantial enhancement in mineralization efficiency and molybdenum recovery. The proposed approach, therefore, provides a practical reference for the flotation recovery of molybdenum tailings as well as other micro-fine, low-grade metal tailings.

Efficient hydrogen generation through water electrolysis depends on the availability of active and stable catalysts for the oxygen evolution reaction (OER). Metal-organic framework (MOF)-derived materials, featuring customizable architectures and adjustable electronic characteristics, represent a promising alternative to precious metals-based catalysts. However, the inevitable pyrolysis process often induces structural collapse and active site blockage, impeding reaction kinetics. To address this challenge, a liquid-phase assisted self-assembly strategy is proposed to construct MOF-derived Co-Fe-Mo sulfides anchored on N-enriched porous carbon/graphene oxide (CoFeMo-S@NC/GO). Electrostatic interactions between carboxyl groups on GO and protonated amine groups (-NH3+) of polyhedral oligomeric silsesquioxane-[3-(2-aminoethyl)amino] propyl-heptaisobutyl substituted (POSS) facilitate the formation of a three-dimensional (3D) interpenetrating network with high surface area. The uniform distribution of MoS2 induces electron redistribution at the Co9S8/FeS/MoS2 interface, optimizing the adsorption energy of oxygen intermediates and thereby enhancing electrocatalytic activity. The CoFeMo-S@NC/ GO exhibits outstanding OER activity in alkaline electrolytes, achieving a low overpotential of 211 mV at 10 mA cm(-2), coupled with excellent long-term durability. This work provides a facile approach to simultaneously modulate the geometric architecture and electronic states of MOF-derived composites for superior electrocatalysis.

Press-formed geopolymers derived from chlorinated distillation residue (CDR) were investigated as waste-derived solid matrices with potential construction-related and arsenic-immobilization applications. The effects of forming pressure and liquid-to-solid (L/S) ratio on compressive strength and microstructure were investigated. The results show that higher forming pressure clearly improved compressive strength by increasing particle contact and making the internal structure denser. The main reaction products, however, did not change greatly. The 28-day compressive strength increased with forming pressure and reached a maximum of 41.52 MPa at 45 MPa. However, 25 MPa was selected as the reference pressure for the subsequent L/S-ratio experiments because visible liquid exudation and paste overflow occurred at higher pressures. In contrast, the L/S ratio showed a non-monotonic effect. A value of 0.375 yielded a dense and well-connected matrix with the highest compressive strength of 32.23 MPa, whereas both lower and higher ratios resulted in less favorable structures. Leaching tests demonstrated that arsenic immobilization strongly depended on environmental conditions. Under neutral conditions, arsenic was mainly retained through physical encapsulation within the amorphous gel, while under acidic conditions, the addition of alkaline components and soluble iron salts further enhanced immobilization performance. These findings provide a potential route for converting CDR into mechanically stable geopolymer matrices.

Alkali residue, which contains silicon and aluminum components from chlorinated distillation residue through alkali leaching, can be used as a raw material for the preparation of geopolymer. However, only a few studies have focused on preparing geopolymer using alkali residue. In the present study, the effects of preparation method (casting molding method and press molding method) and alkali residue content on compressive strength were explored, characterized by XRD, FTIR, TG, NMR, and N2 adsorption-desorption isotherms. The results show that the compressive strength first increases and then decreases with increasing alkali residue content, reaching a maximum of 37.6 MPa at 70% residue content under the pressing method. Compared with casting, pressing significantly enhanced the geopolymerization degree and produced a denser amorphous gel, as confirmed by FTIR and 29Si NMR analyses. The optimized alkali residue content and pressing condition effectively promoted Si-Al dissolution and gel network formation, demonstrating a feasible approach for the resource utilization of alkali residues.

This study employed a deep flotation separation column (DFSC) that establish static separation conditions capable of adapting to the nonlinear physical characteristics of mineral particles. Computational fluid dynamics numerical simulations were conducted to systematically analyze the flow field characteristics and flow intensification mechanisms in the DFSC. A pilot-scale flotation experimental system was constructed based on the DFSC to develop a separation process for CGFS, and comprehensive experimental investigations were conducted. The simulation results showed that the flow field distribution in the DFSC was minimally impacted by the feed flow rate, whereas the pipe and cyclone flow zones were significantly affected by the circulation pressure. The experimental findings revealed that the liquid level drastically impacted the ash content in unburned carbon, with excessive levels markedly increasing the ash content. Increasing the feed flow rate reduced the slurry retention time in the cylinder, which decreased the unburned carbon yield and ash content. Increasing the circulation pressure intensified turbulence in the mineralized zones, thereby affecting the flotation efficiency. The process yielded a net profit of 502,600 CNY per 10,000 tons of CGFS treated, further supporting its economic attractiveness.

To investigate the effects of flow conditions and surfactant concentration on flow field characteristics in the near-wall region of a bubble, this study developed an integrated visualization experimental system that combined particle image velocimetry (PIV) and high-speed photography. This system allows for precise observation of the flow structure around the bubble surface. By systematically varying the bubble Reynolds number (Reb) and the concentration of methyl isobutyl carbinol (MIBC), the variations of key parameters, such as streamline patterns, interfacial shear stress, surfactant adsorption angle, and slip velocity, were quantitatively analyzed under different operating conditions. The results indicate that the introduction of MIBC significantly alters the interfacial properties of the bubble, thereby changing its flow characteristics. Flow field visualization shows that the accumulation of surfactant at the interface causes streamline deflection and induces flow separation at the bubble rear, resulting in a distinct low-velocity stagnation zone. The streamline deflection point moves forward with increased MIBC concentration but moves backward with increased Reb. Analysis of the slip velocity further shows that MIBC suppresses interfacial slip using the Marangoni effect, causing the bubble surface to transition from a free-slip to a nearly no-slip. At the adsorption front, there is a sharp drop in slip velocity, and the position of this drop corresponds to the streamline deflection point. Moreover, increasing MIBC concentration significantly reduces the influence of Reb on both the adsorption angle and slip behavior, indicating that the dominant mechanism governing the interfacial state gradually shifts from “flow-controlled” to “adsorption-controlled.”

Considerable valuable molybdenite (MoS2) remains in copper–molybdenum (Cu–Mo) sulfide flotation tailings due to ore characteristics and limitations of conventional separation technologies. Efficient recovery is challenging because these tailings are typically fine-grained and exhibit complex mineral intergrowth. To address this issue, a turbulent mineralization–static separation (TMSS) separator was developed based on the cyclonic–static micro-bubble flotation column (FCSMC) by decoupling and independently intensifying the mineralization and separation processes. Computational fluid dynamics simulations showed that the TMSS generated strong turbulence in the mineralizer and a stable flow regime in the separator, enhancing mineralization efficiency and separation selectivity. Laboratory tests indicated that the FCSMC achieved superior upgrading performance, whereas the TMSS exhibited higher recovery efficiency, with a single-stage Mo recovery of 86.14% and tailings grade reduced to 0.07%. Based on their complementary advantages, an intensified flowsheet consisting of TMSS roughing/scavenging and FCSMC cleaning was established and validated in pilot-scale production. Under a feed grade of 0.30% Mo, a concentrate grade of 17.26% and recovery of 46.99% were achieved. Economic evaluation confirmed the feasibility and industrial potential of the proposed process, providing a promising route for efficient Mo recovery of fine-grained Cu–Mo tailings.

The application of graphene nanosheets (GNs) in low-carbon refractories is hindered by their poor dispersibility and weak interfacial bonding with the matrix of the latter. In this work, we developed a phenolic resin (PF) assisted ball milling exfoliation strategy using flake graphite (FG) as the raw material to prepare a homogeneous GNs/PF slurry, this approach enables the in-situ exfoliation of FG into well-dispersed GNs. When incorporated into MgAl2O4-C refractories, the GNs/PF slurry significantly improved the homogeneous dispersion and interfacial bonding of the GNs with MgAl2O4. Compared to the control samples with and without FG, the counterpart containing GNs exhibited superior high-temperature performances, including an increase of up to 60 % in oxidation resistance, an 18.7 % improvement in thermal shock resistance, and a significant reduction in slag penetration depth from 1095 mu m to 590 mu m. This work establishes an economically feasible route for the largescale production of high-performance GNs-reinforced low-carbon refractories.

Sodium-ion batteries are promising candidates for large-scale energy storage because of the abundance and low cost. However, cathode development remains a major bottleneck. O3-type layered oxides exhibit high theoretical capacities, yet their polycrystalline nature causes renders them susceptible to grain-boundary fracture during cycling, resulting in capacity degradation. By contrast, single-crystal structures offer superior structural robustness and electrochemical stability but face challenges in synthesis due to their intrinsic sensitivity to air and moisture. Herein, we report a NaBr-assisted molten-salt route to fabricate large-sized O3-type NaCu0.1Fe0.42Mn0.48O2 single-crystals with large lateral size up to 27.3 μm. The cathode delivers an initial discharge capacity of 126 mAh g-1 within 2.0-4.2 V. After 100 cycles at 0.5 C, the cathode retains 70% of its initial capacity. Structural characterization confirms excellent lattice integrity and interfacial stability during cycling. This work provides a valuable strategy for O3-type layered oxides and the development of sodium-ion batteries.

High-entropy alloy materials (HEAs) have emerged as highly promising electrocatalysts, significantly addressing global energy shortages. Their tunable structural composition, multi-metal synergistic effects, adjustable d-band centers, and dynamic evolution of surface oxidation states enable HEAs to exhibit outstanding catalytic activity in electrolytic water splitting, carbon dioxide electrocatalytic reduction, and fuel cells. However, when using high-entropy alloys as electrocatalysts, challenges remain in selecting constituent elements, controlling particle size, and regulating structural morphology, which can impact their performance. To achieve complex or sequential reactions involving multiple intermediate steps, regulating their dimensions and morphologies is already a cutting-edge field of electrocatalysis research, enabling them to serve as electrocatalysts with controllable characteristics. Although numerous studies have explored the relationship between structural morphology and performance, systematically elucidating the structure-property relationship remains challenging. Therefore, this review will cover new discoveries regarding HEA in electrocatalysis, systematically summarize synthesis strategies for HEAs with different structures, investigate the unique catalytic performance of HEAs under various structural conditions, and explore the general relationship between structure and performance. Finally, effective strategies for optimizing HEA catalysis will be proposed, providing new directions for the future design and synthesis of high-quality HEA.

Electrochemical water splitting is pivotal to sustainable hydrogen production, yet its efficiency remains constrained by the intrinsic limitations of non-noble metal catalysts, including moderate conductivity, inadequate stability, and insufficient bifunctional activity. Herein, a novel two-dimensional 2D/2D FeMoS/CoFe-MOF heterostructure is constructed via a two-step hydrothermal method, with single-phase bimetallic sulfide FeMoS as a multifunctional template. The FeMoS template not only guides the oriented growth of CoFe-MOF nanosheets, effectively suppressing their agglomeration, but also enhances the graphitization degree of the composite, thereby enhancing its electrical conductivity and structural stability. Furthermore, FeMoS promotes surface reconstruction of the heterostructure, leading to the formation of highly active γ-FeOOH species. The interfacial charge redistribution within the FeMoS/CoFe-MOF heterostructure facilitates the tailored electronic tuning of the active metal centers. This optimization of the Co and Fe valence states constitutes a critical factor in enhancing the bifunctional electrocatalytic activity. As a result, the FeMoS/CoFe-MOF exhibits excellent catalytic performance, requiring overpotentials of 274 mV for oxygen evolution reaction (OER) and 202 mV for hydrogen evolution reaction (HER) at 10 mA cm−2. The assembled electrolyzer achieves 10 mA cm−2 at a cell voltage of 1.68 V and demonstrates stable operation for over 100 h. This work demonstrates a versatile templating strategy for developing high-performance MOF-based heterostructures as efficient electrocatalysts.

Electrochemical CO2 reduction to formate is attractive for sustainable chemical production, but further progress is limited by the difficulty of simultaneously regulating selectivity, interfacial transport, and catalyst stability in Cu-based systems. Herein, we report a boron-modified dual-layer hollow CuInCeOx nanotube catalyst (B(CuInCe)Ox-DNTs), which can serve as a multicomponent oxide platform for facilitating the electroreduction of CO2 to formate. Boron incorporation is used to regulate the local electronic/defect environment, while the dual-layer hollow nanotube architecture improves interfacial accessibility and gas/electrolyte transport. The optimized catalyst delivers a formate Faradaic efficiency of 74.87% at −1.0 V vs. RHE with a partial current density of 21.12 mA cm−2 in an H-type cell. Structural and spectroscopic analyses reveal that boron incorporation suppresses CuO crystallization, increases oxygen-deficient species, and stabilizes low-valent Cu/Ce surface states. In-situ spectroscopic studies and theoretical calculations further indicate that boron incorporation strengthens CO2 adsorption and lowers the free-energy barrier of the key *OCHO → *HCOOH protonation step, thereby shifting the reaction competition toward the formate pathway. This work provides a multicomponent oxide design strategy for understanding and regulating the interfacial behavior of Cu-based catalysts in formate-selective CO2RR.

Spray cooling depends on the collective action of myriad microdroplets impacting a hot surface. By studying the heat transfer mechanisms that occur when droplets come into contact with a surface, it is possible to determine the influence of various factors on the cooling efficiency of these droplets. In this paper, the heat transfer behavior of droplet impact on high-temperature steel pipes was studied by using numerical simulation methods. A hot-rolled seamless steel pipe is used to investigate the effects of droplet diameter (1-10 mm) and impact velocity (0.5-4 m/s) on the heat transfer under high temperature conditions. The results show that various process parameters exhibit the same influence pattern on heat transfer for both the inner and outer walls. The maximum heat transfer coefficient increases with the increase in the droplet impact velocity, but the cooling duration gradually decreases with the increase in the impact cooling velocity. At a fixed impact velocity, increasing the droplet diameter decreases the peak heat transfer coefficient. It is worth noting that under the same process parameters, the heat transfer coefficient of the outer wall surface is greater than that of the inner wall.

ABSTRACT Due to their versatile and tunable surface and bulk chemistry, MXenes have great potential as electrocatalysts for batteries and supercapacitors. When compared with other electrocatalytic processes, in electrocatalytic reactions, MXenes could improve ion diffusion and charge transfer by either providing functional groups binding to the surface metals to block the diffusion path or offering additional adsorption sites for metal cations or intermediate products on the material surface, so the electrocatalytic activity of MXenes should be sensitive to the surface configuration. Very recently, researchers revealed that introducing defects and strictly tuning the electronic property of the MXene surface could greatly improve its electrocatalytic efficiency; however, the exact mechanism by which defects could improve the electrocatalytic properties of MXenes was still unclear. In this study, authors classify surface defects in MXene, discuss the formation mechanism of each kind of defect, and demonstrate the application of atomic‐level characterization tools to track the evolution of defects. Furthermore, based on the defect mechanics principles, we propose a rational design approach for MXene surface structures. Additionally, this paper discusses the development and application of defect structures in electrocatalytic efficiency improvement. Based on the analysis of the challenges existing in the MXene electrocatalysis, a future research direction is proposed. In this review, we establish a conceptual framework for MXene applications in electrocatalysis. This study advances the development of MXene materials in energy systems, provides the defect design strategies for researchers in further investigation on MXenes, and offers the emerging trends in this field.

Hexagonal boron nitride (h-BN) neither wets nor reacts chemically with molten metals and slag, demonstrating an excellent corrosion resistance. In this work, a boehmite-coated h-BN was prepared via hydrothermal method, which subsequently be incorporated into MgO castable for the anti-corrosion of molten slag. Because of the natural hydrophobicity of starting h-BN (WCA of similar to 150 degrees), the boehmite-coating endowed them with a hydrophilic behavior (similar to 46 degrees), which could ensure the homogeneous dispersion of boehmite-coated h-BN in MgO slurry. The h-BN-modified MgO castables exhibited a superior non-wettability performance than its unmodified counterpart. A high-temperature contact angle of similar to 33 degrees between the slag and modified MgO castable was detected when 2 wt% of h-BN was used, which was higher than that of unmodified one (similar to 19 degrees). Correspondingly, the slag penetration depth of former case was reduced by 44.1 % over the latter one.

ABSTRACT The widespread application of perovskites in fields such as photovoltaics, light‐emitting diodes, and catalysis has brought about new challenges related to environmental pollution. The development of stable and efficient perovskite materials has become a key technological breakthrough for ensuring human health and ecological safety. High‐entropy (HE) materials, due to their unique multi‐element composition, compositional tunability, and entropy stabilization, have opened new avenues for regulating the performance and expanding the functionality of perovskites. Therefore, we comprehensively summarize the latest research progress on HE perovskites (HEPs) in terms of structure, synthesis, and performance. Furthermore, we discuss the applications of HEPs in fields such as energy conversion and storage, optoelectronic devices, and catalysis. Finally, we outline the current technical challenges and future prospects for HEPs. Overall, this review aims to drive innovation and application in the field of HEPs, thereby advancing the development of next‐generation energy and electronic devices.

Petroleum pitch, a soft-carbon precursor rich in aromatics, facilitates the formation of graphitic microdomains, thereby enhancing lithium-ion (Li+) diffusion and structural stability. In this work, a P2O5-assisted method was developed to simultaneously cross-link the molecular chains of pitch and introduce phosphorus dopants, yielding a carbon material with an expanded interlayer spacing (0.361 nm), increased structural disorder, and a hierarchical porous texture. The P2O5-induced cross-linking disrupted the layer ordering, increased the specific surface area and porosity, and created additional Li+ migration pathways. Moreover, phosphorus doping increased the interlayer spacing via enhanced interlayer repulsion, thereby accelerating Li+ transport. Consequently, the material delivered an initial charge capacity of 578 mA h g1 and retained 94% of its capacity after 1000 cycles at a current density of 0.5 A g-1. In situ Fourier transform infrared (FTIR) and wettability measurements revealed a rough, pore-rich surface that improved electrode-electrolyte wettability and facilitated Li+ desolvation, thereby contributing to the enhanced cycling stability. Overall, phosphorus doping significantly enhances the lithium storage performance of pitch-derived soft carbon and provides a viable route for the resource utilization of petroleum pitch.