High-temperature molten salts serve as crucial working fluids in thermal-energy storage, high-temperature metallurgy, and molten-salt reactor systems, where gas evolution and injection introduce complex gas–liquid interactions. The motion of bubbles, including formation, detachment, rising, deformation, coalescence, and breakup, governs heat and mass transfer, flow mixing, and overall operational stability. Owing to high viscosity, strong interfacial tension, and pronounced temperature dependence, molten salts exhibit a viscosity-dominated and capillary-dominated regime that fundamentally differs from conventional liquid systems. This review summarizes recent progress in understanding molten-salt bubble dynamics, covering interfacial evolution, wake behaviors, and multiscale coupling mechanisms, along with advances in high-temperature imaging, interface-resolved simulations, and reactor-scale modeling. However, significant challenges remain, particularly the lack of direct measurements of thin-film drainage, limited accessibility to submicron interfacial structures, and incomplete closure models for bubble interaction and transport. Strengthening property databases, enhancing in-situ diagnostics, and establishing coordinated multiscale validation approaches will be essential for transitioning molten-salt bubble research toward predictive design and control of high-temperature gas–liquid systems.

Biomass reforming is a sustainable route for thermochemical hydrogen production and carbon-efficient biomass utilization. This study systematically compared conventional steam reforming (C-SR) and sorption-enhanced steam reforming (SE-SR) through thermodynamic analysis under varying temperature, pressure, steam-to-carbon ratio (S/C), and calcium-to-carbon ratio (Ca/C). Increasing temperature and S/C, together with decreasing pressure, promoted H2 formation, while CaO addition enhanced in-situ CO2 capture and shifted the equilibrium toward hydrogen production. The conversion of feedstock carbon to gaseous products (XC,g) exceeded 97% under the selected SE-SR conditions. Excessive CaO addition beyond Ca/C = 1 provided limited further improvement. To balance hydrogen productivity, energy demand, and biomass consumption, a weighted matrix method was developed using QD/H2 and YBiomass/H2 as evaluation indicators. The optimal conditions were 700 °C, 1 bar, and S/C = 2 for C-SR, and 650 °C, 1 bar, and S/C = 2 for SE-SR. Under optimal SE-SR conditions, H2 yield and fraction reached 1.60 Nm3/kg and 97.1%, respectively, while QD/H2 and YBiomass/H2 decreased by 5.1% and 17.3%, respectively, with improved hydrogen yield and selectivity.

Tar formation and catalyst deactivation are critical bottlenecks hindering biomass gasification. Microwave (MW) heating and metal-organic frameworks (MOFs)-derived catalysts exhibit great promise for tar conversion. Herein, MOFs-derived carbon catalysts were synthesized via an in situ self-confinement strategy. The 5Ni-5Co@C catalyst achieved 95.03% phenol conversion and 84.60% H2 yield at 800 °C under thermal catalysis. Remarkably, 400 W low-power MW catalysis realized complete phenol conversion, with 80.80% H2 yield and 68.90% CO selectivity. MW selective heating induced pronounced interfacial polarization at the metal-carbon heterojunction, forming local hotspots to promote CO formation from phenoxy radicals. Meanwhile, MW-induced worm-like carbon nanotubes from carbon deposition effectively suppressed catalyst coking and sintering. For real biomass MW gasification, the 7Ni-3Co@C catalyst delivered 40.92 mmol/g H2 yield and 67.78 mmol/g syngas yield. This work provides a new strategy for MOFs-derived catalyst design and elucidates mechanistic differences between thermal and MW heating in tar conversion.

The electrochemical nitrate reduction reaction (NO3RR) to ammonia (NH3) offers a sustainable route for green-electricity-driven and nitrogen-negative NH3 synthesis, circumventing the energy- and carbon-intensive Haber-Bosch process. However, it is challenging to regulate surface-bound hydrogen intermediate (active *H) during NO3RR, as *H is not only required for the hydrogenation steps of NO3RR but also fuels parasitic hydrogen evolution reaction. Here, an atomic-scale hydrogen spillover strategy is realized by atomically dispersing isolated Pt atoms on Cu nanowires to construct Pt1Cu single-atom alloy (Pt1Cu SAA), enabling efficient water activation and interfacial *H utilization. Pt1Cu SAA achieves a 92.4% Faradaic efficiency and an NH3 yield rate of 16.4 mg cm−2 h−1, outperforming most recently reported Cu-based self-supported catalysts. Electron paramagnetic resonance and tert-butanol inhibition experiments verify the in-situ generation and involvement of reactive *H species on Pt sites. In-situ electrochemical measurements uncover that atomically dispersed Pt promotes nitrate adsorption and hydrogenation while suppressing nitrite accumulation. Furthermore, theoretical calculations reveal that the single-atom Pt electronically and geometrically facilitates water dissociation and *H spillover and utilization, lowering the energy barrier of the potential-limiting *NO → *NOH step and enabling selective, high-rate NO3−-to-NH3 conversion. This work demonstrates a general strategy of regulating *H for sustainable ammonia synthesis and other hydrogenation reductions.

The steadily increasing production of waste tires (WTs) from the automobile industry poses significant challenges due to their poor biodegradability, environmental risks, and potential threats to human health. Pyrolysis is considered an effective method for converting WTs into high-value products, facilitating resource recovery and sustainable development. However, conventional WT pyrolysis usually suffers from low efficiency, and the derived pyrolysis oil typically requires further upgrading before being used as an alternative to middle distillate fuels. In this study, a novel "swelling pretreatment + microwave pyrolysis" strategy is proposed to enhance both pyrolysis efficiency and oil quality, and to systematically investigate the effects of swelling pretreatment on pyrolysis behavior and product distribution. This work features the integration of swelling pretreatment with microwave pyrolysis and the systematic comparison of WTs pretreated with different waste-derived swelling agents, providing new insight into the coupling mechanism for improving both pyrolysis performance and product upgrading. Experimental results indicated that the swollen WTs with waste engine oil treatment significantly improved the pyrolysis oil quality. The content of benzene, toluene, ethylbenzene, and xylene (BTEX) in the pyrolysis oil increases from 20.64% to 32.63%, and the pyrolysis oil yield rises from 35.73% to 40.79%. In addition, the proportion of monocyclic aromatic hydrocarbons increases from 56.37% to 66.72%, while that of polycyclic aromatic hydrocarbons decreases from 20.70% to 14.77%, indicating a significant improvement in oil quality. This study provides an effective strategy for enhancing WT pyrolysis performance and promoting high-value product production, contributing to energy recovery and reducing dependence on non-renewable resources.

The in-situ conversion of tar generated during pyrolysis/gasification remains limited by the unclear role of CO2 in plasma systems, where CO2 may either promote reforming by supplying reactive oxygen species or inhibit hydrocarbon cracking through energy competition. In this work, a CO2/Ar microwave plasma torch was developed for toluene conversion as a representative tar surrogate. CO2 addition markedly altered the discharge morphology and excited-species distribution, while its net effect strongly depended on the matching between energy input and reactant loading. Increasing microwave power from 600 to 1050 W enhanced toluene conversion from 64.77% to 81.10% and H2 selectivity from 85.24% to 97.36%, indicating that higher energy input favored deep cracking and dehydrogenation. In contrast, increasing the CO2 fraction from 5% to 25% reduced toluene conversion from 90.77% to 65.63% and suppressed H2 formation, mainly due to the competitive consumption of energetic electrons and excited Ar species by excess CO2. Optical emission spectroscopy and thermal imaging suggested the formation of CO2-derived O species and C2-related excited species, supporting secondary reforming between CO2-derived reactive species and toluene-derived fragments. However, excessive CO2 shifted the reaction pathway toward incomplete cracking, increasing C2H2 and CH4 selectivities. These results demonstrate that CO2-assisted microwave plasma tar reforming operates under a trade-off regime, where optimal performance requires careful matching of microwave power, CO2 fraction and tar loading. This study provides guidance for plasma-based tar removal and gas upgrading of waste-derived syngas.

Tar generated during the pyrolysis and gasification of organic solid waste severely hinders the large-scale and efficient utilization of this technology. To address the high energy consumption, elevated reaction temperatures, and insufficient catalyst stability associated with conventional tar treatment processes, a dual-functional highentropy oxide catalyst ((FeCoNiMnCr)3O4@SiC) supported on SiC was successfully synthesized via a sol-gel method and applied to microwave-assisted CO2 dry reforming of tar. Material characterization results indicate that the disordered solid solution of multiple metal cations significantly intensifies lattice distortion and promotes the formation of oxygen-vacancy-related defect structures. These structural features may facilitate the adsorption and activation of reactant molecules, while also endowing the material with favorable lowtemperature reducibility and enhanced COQ adsorption capability. Under microwave irradiation, the highentropy oxide catalyst exhibits efficient electromagnetic energy coupling and rapid heating, enabling toluene conversion exceeding 90% at relatively low temperatures compared to conventional electric heating. In addition, the catalyst exhibits excellent anti-coking ability, effectively suppressing the formation of surface carbon deposits during long-term operation, thereby maintaining outstanding catalytic activity and structural stability. Postreaction characterizations reveal that, during the reforming process, partial Co and Ni species undergo in situ exsolution to form metallic nanoparticles, accompanied by the generation of abundant oxygen vacancies, which synergistically promote the reforming reaction. The results demonstrate that the integration of microwave heating with high-entropy oxides provides a feasible strategy for the low-temperature and efficient conversion of tar, and shows significant research value and application potential for enhancing the resource recovery of organic solid waste.

As a promising high-capacity hydrogen storage material, the practical application of MgH2 is impeded by sluggish reaction kinetics and high thermodynamic stability. In this study, a ternary CeO2-Ni-rGO catalyst was designed to synergistically address both challenges. Electronic coupling between CeO2 and Ni promotes the generation of abundant oxygen vacancies, which weaken the Mg-H bond and significantly reduce the dehydrogenation temperature. Meanwhile, Ni acts as an active site for H2 dissociation and establishes a reversible Mg2Ni/Mg2NiH4 "hydrogen pump", thereby accelerating hydrogenation and dehydrogenation kinetics. The conductive rGO framework further facilitates interfacial charge transfer and prevents catalyst agglomeration. With the addition of 10 wt% CeO2-Ni-rGO, the MgH2 composite attains 4.0 wt% hydrogen uptake within 60 s at 100 degrees C, with its hydrogenation activation energy decreasing to 52.45 kJ/mol. Concurrently, the onset dehydrogenation temperature drops to 195 degrees C, with the corresponding dehydrogenation activation energy dramatically reduced from 144.4 kJ/mol to 58.9 kJ/mol. Moreover, the composite retains 97 % of its initial capacity after 30 cycles, demonstrating excellent cycling durability. Density functional theory (DFT) calculations reveal that Ni 3d states markedly increase the electronic density near the Fermi level and strengthen orbital hybridization with CeO2, rGO, and MgH2, enabling accelerated interfacial electron migration and facilitating both vacancy formation and H- transport. These results confirm that the CeO2-Ni-rGO ternary catalyst effectively overcomes both kinetic and thermodynamic barriers, offering a robust and promising strategy for advancing MgH2-based solid-state hydrogen storage.

The utilization of biomass resources is of significant importance. However, the complexity of biomass thermochemical conversion processes and the performance limitations of conventional catalysts restrict the stable selection of reaction pathways and ultimately affect catalytic yields. With the rapid development of synthesis techniques and machine learning, nanoscale high-entropy alloys (HEAs) with targeted properties can now be accurately predicted and synthesized. The diverse compositions and structures of HEAs enable versatile catalytic selectivity, while their unique four core effects enhance catalytic activity and stability. This review primarily elaborates on the specific applications of HEAs in biomass thermochemical conversion. It covers the fundamental characteristics of HEAs, preparation methods, and machine learning-driven design strategies. Summarized the directional conversion and value-added research of high-entropy alloys in biomass thermal conversion intermediates. This demonstrates the excellent application adaptability of high-entropy alloys in complex reaction systems. Finally, prospects for the rational design of high-entropy alloy catalysts and their application in biomass refining technologies are outlined.

Conventional pyrolysis technology for recycling waste tires inherits the drawback of complex product composition for their high-value utilization. Here, we proposed a "microwave-intensified thermocatalytic" treatment for swollen waste tires to regulate product distribution, thereby improving pyrolysis oil composition and increasing the relative distribution of limonene. The optimized carbon black (CB) achieves a yield of pyrolysis oil up to 48.23%. After modification with nickel ions (Ni-CB), the pyrolysis oil yield increases to 50.24%. Moreover, CB and Ni-CB could increase the relative abundance of limonene in pyrolysis oil to 11.41% and 18.03%, respectively, compared to that in the microwave thermocatalysis system without catalyst addition (8.73%). This work of waste tire pyrolysis not only contributes to sustainable waste management but also supports the circular economy by transforming a persistent waste stream into marketable resources.

With the rapid advancement of portable wearable electronics, flexible supercapacitors have ushered in new development opportunities. In recent years, MXene and its composites have demonstrated potential as advanced supercapacitor electrode materials due to their outstanding theoretical capacitance, specific surface area, conductivity, hydrophilicity, and mechanical flexibility. This review traces the development of MXene and summarizes common synthesis strategies, with a focus on the effects of different preparation methods on its structure and properties. Departing from previously reported work, this review draws from the practical requirements of flexible supercapacitors to conduct an in-depth analysis of the key factors influencing the charge storage, rate capability, cycling life, and mechanical flexibility of the devices. It summarizes common design strategies for MXene composites currently used to enhance device performance. Additionally, this study analyzes key challenges facing MXene-based electrode materials, including issues such as self-stacking of layers, insufficient oxidation stability, limited energy density, and structural degradation under complex deformation conditions. Mitigation strategies are summarized, including optimizing synthesis methods and constructing composite systems integrating carbon materials, conducting polymers, and transition metal compounds. Finally, future research directions for MXene in flexible energy storage are explored, emphasizing the need to achieve a balance between performance and manufacturability through synergistic regulation at structural design, interfacial engineering, and device levels. This review aims to provide theoretical guidance for the development of practical MXene-based wearable energy storage devices.

Methane pyrolysis is emerging as a promising carbon-negative hydrogen production technique, offering an energy-efficient alternative to conventional methane steam reforming. A novel microwave discharge plasma (MDP) system is introduced to enhance methane pyrolysis, enabling the simultaneous production of carbonnegative hydrogen and high-quality carbon materials. Key operational parameters, including microwave power, flow rate, gas composition, and reactor geometry, have been systematically investigated for their significant effects on methane pyrolysis. Optimal system performance is achieved at 300 W microwave power and a flow rate of 0.07 m/s, yielding a methane conversion rate of 99.8 % and a specific energy requirement (SER) of 180 kJ/mol, with few-layer graphene produced as a valuable byproduct. The critical role of energetic electrons, argon species, and methane interactions in C-H bond cleavage and carbon nanostructure formation is elucidated through optical emission spectroscopy (OES) analysis. Additionally, density functional theory (DFT) calculations reveal the influence of microwave fields on methane adsorption energy over tungsten surfaces, shedding light on the mechanisms of methane cracking product formation. This study provides fundamental insights into MDP methane pyrolysis, advancing sustainable methane conversion and utilization strategies.

Oily sludge is a kind of industrial hazardous waste that contains a lot of harmful substances. It has high water content and oil content. Demulsification is the key link for its resource utilization. Based on the unique heating characteristics of microwave heating, this paper uses microwave heating method to demulsify oily sludge in refineries. The effects of microwave power, temperature, stirring time, and additives on the demulsification of oily sludge are studied. The composition of each layer of the oil phase is analyzed to explore the possibility of oil reuse. The orthogonal test results show that the order of the influence of various factors on the dehydration rate of sludge is: temperature>power>stirring time; microwave power 700 W, temperature 55 degrees C, and stirring time 10 min, the dehydration rate of sludge reaches the maximum value of 69.3%; adding sludge pyrolysis residue can significantly improve the efficiency of sludge dehydration; based on the results of microwave primary demulsification experiments, a deep demulsification and dehydration method for sludge is proposed. Based on the carbon number method, the relative contents of the liquid phase product were corrected, and it was found that the three layers of liquid phase product composition after demulsification and centrifugation were significantly different. The upper layer was mainly composed of gasoline (69.54%), and the middle layer was mainly composed of diesel (89.55%), the lower layer was mainly heavy oil components (75.87%).

The photocatalytic hydrogen (H2) evolution performance of graphitic carbon nitride (g-C3N4) named as CN is mainly limited by poor charge separation and low surface catalytic activity. To address these challenges, we report composite photocatalysts by integrating CN with cobalt embedded in nitrogen-doped carbon (CoNC) cocatalyst termed as CN/CoNC-X via a tailored pyrolysis strategy using urea and zeolitic imidazolate framework-67 (ZIF-67) precursors. In this work, CoNC serves as an efficient cocatalyst, where Co sites facilitate abundant surface-active sites for H2 production, while the NC framework enhances conductivity and promotes charge transport at the interfacial surface. The firm interface between CN and CoNC creates intrinsic electronic interactions that accelerate the flow of electrons from CN and hinder charge carrier recombination. The optimal CN/CoNC-5 composite achieves an optimized H2 production rate of 1794.1 mu mol h & horbar;1 g & horbar;1 under visible-light irradiation (lambda >= 420 nm), which is nearly 6.1-fold greater than bare CN (292.4 mu mol h & horbar;1 g & horbar;1). In addition, the optimal designed photocatalyst demonstrates stable H2 production over four consecutive reaction cycles under visible-light illumination for up to 16 h. This significant enhancement confirms the crucial role of the CoNC cocatalyst in tuning charge carrier dynamics and improving surface catalytic efficiency.

The thermocatalytic conversion of abundant and toxic H2S by-products in the oil and gas industry is expected to grow in demand for hydrogen production and simultaneously eliminate this adverse environmental impact. Thermocatalysis offers the merit of employing an established technology at a large scale, a simple reaction mechanism and process configuration, but necessitates higher energy efficiency and larger economics. Herein, a novel electric field-modulated catalytic system for H2S splitting at low temperatures is first constructed. Through an electric field approach, the optimal porous 10 wt% FeNi-S/Al2O3 catalyst exhibits 33.2 % H2S conversion at a low temperature of 400 degrees C, significantly exceeding the 0.2 % conversion of traditional thermocatalysis. Experimental results coupled with in-situ optical emission spectroscopy confirm that, under an electric field, the catalysts' interparticle discharge enhances high-energy electron-H2S and excited Ar atom-H2S collisions, which contributes to S-H bond breakage. Moreover, DFT calculations show electric field improves the surface electron migration, strengthening the adsorption of H2S and reducing the energy barrier of its decomposition. This work provides new insights into the synergistic electric field-catalyst effect, and proposes recommendations for converting waste H2S into sustainable H2 energy in technological applications.

Aluminum nitride (AlN) ceramics exhibit exceptional thermal and electrical properties, making them highly promising candidates for electronic packaging applications and integrated circuits. Nevertheless, the hydrolysis of AlN powder results in formation of Al(OH)(3), which decomposes into Al2O3 during the subsequent sintering process. This reaction increases oxygen content, thereby degrading thermal conductivity of AlN ceramics and further imposing significant limitations on their processing and utilization. Consequently, surface modification of AlN powder is imperative to improve its hydrolysis resistance. In this work, a dual-agent modification strategy utilizing polyethylene glycol (PEG) and lauric acid (LA) was implemented through a straightforward wet ball-milling protocol, successfully forming a chemically bonded encapsulation layer on AlN particles. FT-IR and XPS analyses verified that carboxyl groups (-COOH) of LA engaged in esterification reactions with hydroxyl groups on the oxidized AlN surface, leading to formation of robust ester linkages. TEM images revealed a continuous encapsulation layer with a thickness ranging from 12.2 nm to 16.1 nm. Remarkably, the modified powder maintained a solution pH below 9 after 72 h immersion in water at 40 degrees C, with no discernible alterations in phase composition and microscopic morphology. This chemically stable and low-solubility encapsulation layer effectively obstructs water diffusion pathways, thereby suppressing hydrolysis kinetics. Enhanced hydrolysis resistance was positively correlated with LA dosage. This work proposes an innovative encapsulation-based paradigm for developing hydrolysis-resistant AlN powders and advancing high-performance ceramic fabrication.

A high-activity, low-cost, and easy-to-prepare monolithic catalyst is crucial for the industrial catalytic combustion of volatile organic compounds (VOCs) in a cost-effective manner. In this study, a highly efficient monolithic catalyst, designated as 4GM/COR, was developed by loading 4% graphene-doped α-MnO2 (4GM) catalyst onto pre-etched cordierite (COR) blocks using a straightforward “ball-milling-assisted impregnation” method. The anchoring force of the cordierite pores, generated through oxalic acid etching, enables the uniform and robust loading of powdered 4GM onto COR, preventing detachment under high temperatures or high gas flow rates. The loading rate, specific surface area, and concentrations of Mn3+ and surface-lattice and absorbed oxygen species in the monolithic catalyst increase with impregnation times from 2 to 4, indicating that catalytic activity is optimized through repeated impregnation. Catalytic performance tests demonstrated that the 4-4GM/COR exhibited the highest activity, achieving 90% degradation of toluene at 200 °C under both dry and humid (relative humidity is 85%) conditions. Furthermore, the 4-4GM/COR maintains high catalytic stability and activity even at a large GHSV of 6000 h−1. To conclude, the 4-4GM/COR monolithic catalyst developed in this study not only represents a promising option for industrial applications but also serves as an important reference for the synthesis of monolithic catalysts.

A dual system comprising micro zero-valent iron (ZVI) and pyrite (FeS2) was applied for the remediation of groundwater contaminated by nitrate and ofloxacin (OFL). The removal efficiency for nitrate, total nitrogen (TN), and OFL in the dual-material system with different ZVI-FeS2 weight ratios, dosages, initial pH, and the coexistence ions and organic substances were investigated. Then, the synergetic effect between ZVI and FeS2 and the possible OFL removal pathway in the ZVI/FeS2 system was observed. And finally, the feasibility of reusing ZVI/FeS2 particles was evaluated by recycling experiments. Results showed that the removal efficiency for nitrate and OFL reached up to 44.09 %-66.78 % and 49.67 %-69.29 %, respectively, at a pH range of 5.0-9.0 when the weight ratio and dosage of ZVI/FeS2 were 2:1 and 16 g/L respectively, which were both considerably higher than those of the ZVI or FeS2 system alone. In different co-solutes systems, the OFL and nitrate removal performance of the ZVI/FeS2 material was differed. In addition, mechanism study revealed that FeS2 could relieve the pH increase, accelerate the corrosion of ZVI surface, generate more Fe2+, and promote the generation of new S species (FeS and S22- ) in the dual system. The possible OFL degradation pathway in the ZVI/FeS2 system was established on the basis of the identified intermediate products. OFL degradation was successfully achieved through decarboxylation, demethylation, and piperazine epoxidation. And then, the degradation products were further degraded into smaller oxygen-containing compounds. Recycling experiments indicated that the ZVI/FeS2 particles still showed satisfactory pollutant removal efficiency after five cycles.

Hydrocarbon fuels used in micropower systems offer significant advantages, such as high energy density, lightweight properties, and extended power supply duration, making them the focus of widespread interest. Methane is particularly favored due to its excellent combustibility, ease of preparation, and convenient storage. In this study, ReaxFF molecular dynamics simulation is employed to investigate the influence of three additives (dimethyl ether, hydrogen, and ammonia) on the combustion mechanism of methane fuel. Results show that the pathways of CH4 mainly involve dehydrogenation and oxidation reactions. In CH4/C2H6O system, dimethyl ether is predominantly consumed via two pathways: C-O cleavage and dehydrogenation. These pathways form a significant quantity of active free radicals (such as CH3 and CH3O). In the case of CH4/H2 combustion, hydrogen is consumed to provide H, OH, and HO2 active free radicals via reactions such as H2 + OH -* H2O + H, H2 + O2 -* 2OH, and H2 + 2O2 -* 2HO2. In the combustion of CH4/NH3, ammonia initially undergoes a dehydrogenation reaction involving OH, O, and H free radicals, resulting in the formation of NH2. Subsequently, 65.57 % of NH2 undergoes further reactions to form H2O2N, while 16.39 % of NH2 forms NH radicals. The presence of additives influences the final products in different systems. In the CH4/C2H6O system, the final products include CO, CO2, H2, and H2O. In the CH4/H2 system, the final products consist of CO, CO2, and H2O. Lastly, in the CH4/NH3 system, the final products comprise CO, CO2, H2, NO, NO2, and H2O.