Sustainable Energy & Fuels最新文献

Amid growing global concerns over climate change, the aviation industry is reinforcing its commitment to sustainable development. Current studies confirm that Sustainable Aviation Fuel (SAF) has become a central strategic measure for reducing carbon emissions intensity and mitigating environmental impacts throughout the fuel's life cycle. Among various production pathways, Fischer–Tropsch synthesis (FTS) is widely considered one of the most promising routes for near-term industrial-scale SAF deployment, owing to its high technological maturity and well-established scalability. This article provides a systematic review of the relationship between the composition and content of jet fuel components and their physicochemical properties. It further interprets the technical requirements specified in the ASTM International standard ASTM D7566, Standard Specification for Aviation Turbine Fuels Containing Synthesized Hydrocarbons, with particular emphasis on FTS-derived synthetic jet fuels. Based on current research progress, the paper concludes with a summary and outlook on future technological directions for sustainable aviation fuels.

In this work, porous CoNiMoS (CNMS)-based ternary nanoflower arrays were successfully grown on nickel foam (NF) using a two-step strategy involving hydrothermal synthesis followed by a solvothermal sulfidation process. The influence of sulfidation concentration was systematically investigated to optimize the electrochemical performance. The optimized CNMS@NF electrode exhibits a pronounced charge–discharge activation behaviour and delivers a high specific capacitance of 1940 F g⁻¹ at 1 A g⁻¹. The hierarchical porous architecture, derived from hydroxide precursors, enables improved electrolyte diffusion and efficient exposure of active sites. Notably, this structural evolution leads to a substantial reduction in solution impedance from 4.1 Ω to 2.12 Ω, enhancing charge transport kinetics. The electrode achieves an impressive energy density of 349.2 Wh kg⁻¹ and a power density of 1631 W kg⁻¹, while retaining 70% of its initial capacitance after 4000 charge–discharge cycles, demonstrating excellent long-term stability. The superior electrochemical performance is attributed to the synergistic interaction among Co, Ni, and Mo species and the enrichment of S²⁻ anions, which collectively stabilize the nanoflower structure and promote robust redox activity. These findings position the CNMS@NF electrode as a promising candidate for high-performance energy storage applications.

The increasing demand for advanced energy storage in applications like wearable electronics, electric vehicles, and renewable technologies encourages the growth of advanced supercapacitor materials. MXenes, which are two-dimensional compounds made of transition metals, carbides, nitrides, and carbonitrides, attract attention as promising electrode materials due to their strong electrical conductivity, flexibility, water attraction, and easily altered surface chemistry. This review covers significant progress in MXene-based supercapacitors, discussing methods of making them, their structure and the performance characteristics within the realm of pseudocapacitive energy storage mechanisms in supercapacitor architectures, and how they are incorporated into devices. Methods for synthesis, such as HF etching, fluoride processes, and new environmentally friendly approaches with alkali and electrochemistry, are examined, and their role in surface alterations and scale-up efforts is emphasized. Physicochemical characteristics of MXenes, including high specific surface area, pseudo-capacitive properties, and good cycling, are investigated to determine their suitability for flexible, solid-state, and micro-supercapacitors. The blending of MXene with carbon, conductive polymers, and metal oxides in electrodes addresses restacking and oxidation, enhancing storage capacity (250–700 F g⁻¹) and energy density (20–70 Wh kg⁻¹). Although they appear promising for use in supercapacitors, MXene-based devices face difficulties in manufacturing due to oxidation stability and safety. Future developments are expected to introduce new materials, promote eco-friendly synthesis, and advance design for wearable, connected devices. Overall, this review consolidates the current understanding and technological progress of MXene-based supercapacitors and outlines pathways for translating their lab-scale success into practical applications.

The manufacture of a novel type of gas diffusion electrode (GDE) for the electroreduction of CO_2, based on nanoporous anodic alumina gas diffusion layers (GDLs), is described. The GDE consists of an array of aligned pores hydrophobised via silanisation, on top of which a layer of a silver or copper catalyst was deposited. The versatility of the fabrication method allows for controlled pore apertures on both sides of the membrane and controlled thickness, further enabling the tailoring of the GDLs' properties to a given type of catalyst.

Single atom Fe sites, doped in CN materials, exhibit outstanding electrochemical activity for CO₂-to-CO conversion. The pyrolysis of ZIF8 is a controllable method for fabricating isolated single atom metal sites. In this study, we propose a new strategy to increase the ratio of Fe in ZIF8 precursors by synergistically replacing Zn²⁺ with Bi³⁺ and Fe³⁺. After precursor pyrolysis, the obtained Bi/Fe–N–C catalysts, consisting of Bi sites and pyrrole-type Fe–N_x sites, serve as efficient electrocatalysts for the CO₂RR. The results show that the optimized catalyst loaded with 94.8 mg per kg_Cat Fe exhibits a high FE_CO of >90.1% over a wide potential range of −0.4 to −0.7 V_RHE (98.2% at −0.5 V_RHE). Insights into the electrochemical reaction mechanism show that this successful design of Bi/Fe–N–C catalysts can provide a stable catalytic site to form *COOH, thus achieving energy-efficient electrochemical CO₂ reduction to CO.

Low-concentration CMM (coal mine methane) (CH₄ <30%) is mostly extracted during coal mining, which discharges directly into the air from mining shafts. Herein, recent advances in CH₄ recovery from coal mine gases are summarized. Among them, studies on the use of different adsorbents (activated carbon, zeolites, and metal–organic frameworks (MOFs)) and adsorption processes are extensively reviewed for use with low-concentration CMM. MOFs demonstrate superior performance due to their tunable pore geometries and customizable surface functionalization. These characteristics enable MOFs to achieve higher CH₄ selectivity than traditional activated carbon or zeolite adsorbents. Current research focuses on scaling up these advanced MOF materials and optimizing pressure swing adsorption (PSA) processes for industrial implementation. Compared to alternative separation technologies, such as membrane separation and cryogenic distillation, PSA exhibits distinct advantages for treating low-concentration CH₄ (1–30%). PSA demonstrates better performance in both product purity and recovery rates while maintaining higher technical and economic feasibility. Future research should focus on optimizing the PSA process and integrating it with other technologies. Such developments could provide economic incentives for the widespread adoption of CH₄ recovery systems in coal mining operations.

The modeling of underground hydrogen (H₂) storage (UHS) requires understanding the thermodynamics of H₂-containing gas mixtures as they approach local equilibrium during storage while subjected to temperature gradients and gravity segregation. Previous investigations using a model based on irreversible thermodynamics have shown the need for experimental measurements of hydrogen thermal diffusion in natural gas to better understand hydrogen composition versus depth during UHS. This work presents thermal diffusion measurements for H₂ in methane (CH₄) at varying temperatures and compositions. The effect on thermodynamic modeling is discussed, and the effect of other cushion gases such as carbon dioxide (CO₂) is also explored. For the H₂–CH₄ system, it was found that the thermal diffusion factor (α_T) increases as a function of composition and temperature, with values ranging from α_T = 0.22–0.36 for H₂ mole fractions ranging from x_H2 = 0.3−0.7. At a fixed composition of 50% H₂ and 50% CH₄, α_T ranged from 0.21 to 0.29 for a median temperature ranging from 250 K to 450 K. Using these values, a reference ideal gas enthalpy of 3.5 kJ mol⁻¹ for CH₄ while setting the reference ideal gas enthalpy of H₂ to 0 kJ mol⁻¹ is needed to properly match the model with the experimental observations at a constant median temperature. For experiments at varying median temperature, a correlation is needed between the enthalpy of the reference ideal gas of CH₄ and the departure of the median temperature from the reference state temperature to match adequately the model with the experimental values. The effect of adding these thermal considerations leads to a more homogeneous mix of H₂ with its cushion gas than previously anticipated. Further study of UHS operations could include the effects of shut-in time to determine gas purity during production cycles.

Herein, N, S co-doped carbon fibers encapsulating hollow Sb nanocrystals (h-Sb@NS-CNFs) were synthesized by a simple ion exchange and electrospinning process. The hollow Sb nanocrystals, in conjunction with the confinement effect of the carbon fibers, can offer faster Na⁺ pathways, decrease the Na⁺ diffusion barriers, and effectively mitigate the structural degradation of the electrode caused by the volume changes of Sb, thereby extending the cycle life of batteries. Additionally, the dual-element co-doping strategy employing nitrogen and sulfur provides more active sites for the Na⁺ reaction and increases the electronic conductivity while simultaneously enhancing the ionic diffusion kinetics, as indicated by density functional theory (DFT) and kinetic analysis. Therefore, h-Sb@NS-CNF exhibits excellent cyclic stability (305.3 mAh g⁻¹ at 2 A g⁻¹ for 900 cycles) and a high-rate capacity (209.3 mAh g⁻¹ at 10 A g⁻¹) as an anode material for sodium-ion batteries.

To advance the application of liquid organic hydrogen carriers (LOHCs) in flow batteries, the mechanism and performance of CoO/NF for the electrocatalytic hydrogenation (ECH) of quinoxaline—prepared by a low-melting-point ionic liquid electrodeposition method—are systematically investigated. The quinoxaline/tetrahydroquinoxaline conversion reaction catalyzed with CoO/NF results in superior ECH activity with low charge transfer impedance (1.624 ohm) and a Tafel slope of 103 mV dec⁻¹; the efficiency of quinoxaline conversion is 99.84%, and the selectivity of tetrahydroquinoxaline formation is 98.73%. The hydrogen in the hydrogenation reaction comes from water, and the active hydrogen atoms (H*) generated on the cobalt surface via the Volmer step are the key intermediates. The electrocatalyzed quinoxaline/tetrahydroquinoxaline reaction is an efficient system for hydrogen storage in flow batteries, providing a scientific basis for hydrogen energy storage and conversion in LOHC-based flow batteries.

Developing efficient and flexible ionic thermoelectric (i-TE) materials is essential for converting low-grade waste heat into usable electrical energy. In this study, we present a new biomimetic strategy for designing high-performance eutectogels that integrate a cesium chloride–ethylene glycol deep eutectic solvent (CsCl:EG DES) with a poly(vinyl alcohol) (PVA)–sodium hydroxide (NaOH) polymer matrix. The resulting CsCl:EG/PVA–NaOH eutectogel exhibits outstanding thermoelectric performance, achieving a record-high Seebeck coefficient of 1.65 mV K⁻¹ at 355 K, significantly surpassing previously reported PVA/NaOH hydrogels and marking the first successful demonstration of thermoelectric operation in the CsCl–EG system. Comprehensive structural and morphological characterization using FTIR, SEM, and EDX confirms the formation of a robust, well-developed bicontinuous network in which CsCl:EG domains are uniformly distributed within the crosslinked PVA matrix. This architecture enables p-type thermoelectric behavior, where directional ionic transport of Na⁺, Cs⁺, Cl⁻, and OH⁻ ions through interconnected percolation pathways is driven by a thermal gradient. Complementary molecular dynamics simulations (GROMACS) further validate the experimental findings, predicting a Seebeck coefficient of 2.06 mV K⁻¹ within the 298–358 K range. The simulations elucidate that the strong hydrogen-bonding network and the presence of multiple mobile ion species facilitate efficient thermodiffusion while maintaining low phonon transport. The synergistic combination of engineered ionic migration channels and phonon-scattering interfaces yields an optimal balance between a high Seebeck coefficient and low thermal conductivity. These features make the CsCl:EG/PVA–NaOH eutectogel a promising candidate for flexible, sustainable thermoelectric devices capable of harvesting low-grade waste heat under ambient conditions.