Sustainable Energy & Fuels最新文献

Biomass-derived carbon materials (BDCMs) represent a versatile and sustainable solution for a range of energy generation and storage applications, owing to their tunable porosity, high surface area, and excellent electrochemical properties. With the growing demand for renewable energy technologies, BDCMs have emerged as promising candidates for supercapacitors, batteries, fuel cells, and catalytic applications. These materials, derived from abundant and renewable biomass sources such as agricultural waste, forestry residues, and municipal solid waste, offer a cost-effective and environmentally friendly alternative to traditional fossil-fuel-based carbon materials. Key synthesis methods, including pyrolysis, hydrothermal carbonization, and chemical activation, enable the development of carbon materials with tailored structural and chemical properties. Additionally, advancements in activation processes, heteroatom doping, and surface modification techniques further enhance the electrochemical performance of BDCMs, making them suitable for high-performance energy devices. Recent studies have demonstrated the potential of BDCMs in applications such as lithium-ion batteries, sodium-ion batteries, supercapacitors, and electrochemical double-layer capacitors, offering high specific capacitances, excellent rate performance, and long cycling stability. This review highlights the synthesis techniques, structural tuning strategies, and emerging trends in BDCMs, with a focus on their impact on energy storage and generation systems. By utilizing biomass-derived materials, this research paves the way for eco-friendly, sustainable energy solutions to address the growing global energy demand.

Layered oxide materials have high theoretical capacity, simple structures and a wider range of elements to choose from. For sodium-ion batteries (SIBs), they are an ideal cathode material. However, these materials are prone to an interlayer slip and phase transition, which limits their application. In order to solve this problem, we designed a P2/O3-type Na_0.85Mn_0.44Fe_0.17Ti_0.05Ni_0.16Mg_0.06Zn_0.06Cu_0.06O₂ (P2/O3-HEO) cathode material based on entropy tuning and biphasic tailoring strategies. We have used a variety of material characterisation techniques to identify the impact of related factors on material performance. The phase transition of the material is effectively mitigated by increasing the constitutive entropy of the material, which mitigates the cycling performance degradation induced by irreversible phase transitions during high-voltage charging and discharging. Meanwhile, the biphasic tailoring strategy improves the discharge capacity of the material to some extent and reduces the structural collapse due to oxygen depletion. The biphasic P2/O3-HEO cathode exhibits a large discharge specific capacity (0.1C, 162.3 mA h g⁻¹) and capacity retention of 72.9% over 300 cycles at 5C within the potential range of 2–4.3 V. As a result, this work provides a different perspective for solving similar problems that occur in composite cathode materials for SIBs.

Fast pyrolysis of woody materials is a technology pathway for producing renewable fuels and chemicals. This is a presentation of isolating needles, bark, and stemwood from a single tree as well as isolating stemwood and whole tree samples from the same species of tree with different ages and pyrolyzing each individually as well as in mixtures. This gives insight into the role of tree anatomical fractions on the resulting intermediate oil product as well as into interactions between these components. The highest carbon content oil (45.1 wt% as received) was produced from a one-to-one mixture of stemwood and needles, followed by the pure stemwood (43.4–43.8 wt% as received), while the lowest oil carbon content was from a one-to-one blend of bark and needles (26.7 wt% as received). The pyrolysis oil yield (combining oil and aqueous where separation occurred) varied from 54 wt% as received (needles) to 72.3 wt% as received (stemwood). When comparing trees of different ages, we find the change in the ratio of the anatomical fractions is a dominant factor in the product composition and yields, while the product composition and yields vary slightly with tree age when only the stemwood is pyrolyzed. Here we present the bench-scale pyrolysis, yields, and product characterization of loblolly pine feedstocks (13- vs. 23 year-old, residues, air-classified residues, whole tree, needles, bark, and stemwood).

A Mg₉₃Ni_3.5Y_3.5 hydrogen storage alloy was prepared using a composition design approach with a protective covering agent method. A self-synthesized 1 wt% nano (Ni–TiO₂)@C catalyst was added by ball milling. The in situ formation of the endogenous long-period stacking ordered (LPSO) phase facilitated the catalytic decomposition of products after hydrogenation. The synergistic effect of the external and in situ endogenous catalysts enhanced the hydrogen absorption and desorption capacities, increased the reaction rate and lowered the temperature corresponding to the maximum hydrogen storage capacity. The composite material absorbed up to 6.39 wt% of hydrogen at 300 °C and 30 bar. Even at 100 °C, it absorbed 3.87 wt% of hydrogen within 2 hours. The enthalpies of formation for the materials Mg₉₃Ni_3.5Y_3.5 and Mg₉₃Ni_3.5Y_3.5 + (Ni–TiO₂)@C (with the added catalyst) were −53.96 and −55.04 kJ mol⁻¹ H₂, respectively. The corresponding hydrogen absorption activation energies were −34.14 and −39.51 kJ mol⁻¹ H₂. In addition, the material displayed excellent cycling stability after 100 cycles with the addition of the catalyst.

Integration of metal-halide perovskite solar cells (PSCs) with thermoelectrics (TEs) to form hybrid PSC-TE tandem devices presents a promising avenue for maximizing solar spectrum utilization. However, prevailing simulation models often rely on predetermined hot side temperatures and frequently overlook real-world performance analysis. Here, we present a comprehensive model for simulating the energy yield and temperature dynamics of the PSC-TE system. Our novel approach incorporates the thermal equilibrium equation to derive the steady-state temperature of the device through simulation. Additionally, we elucidate the significant contribution of background radiation to energy generation and explore the immense potential of PSC-TE tandem systems under various real-world conditions most relevant to practical applications. We demonstrate that PSC-TE tandems can achieve 5% improvement in power conversion efficiency (PCE) under normal conditions. And in some places like Antarctica, the PCE of tandem systems can reach 35.4% with consideration of optical loss, and up to 56.6% with the application of concentrator architecture. We also show their great advantages compared to pure photovoltaic devices in space, with improvement exceeding 50% in PCE; the tandem system can achieve a high PCE up to 76% with its strong ability to maintain device temperature (T_D) and use of background radiation. This proposed modeling framework provides a valuable tool for optimizing the design of PSC-TE tandem systems, with particular emphasis on thermal and optical management strategies.

NiO-Co₃O₄/TiO₂ showed the best catalytic performance for one-step synthesis of 2-cycloamylcyclopentanone from cyclopentanone, which enhanced the competitiveness of cyclopentanone self-condensation. Both intermittent and segmented hydrogenation methods led to increased selectivity for 2-cyclopentenylcyclopentanone. Both acidic and basic substances were added to the reaction integration system, which resulted in a decrease of catalyst activity. The addition of acetic acid could promote the hydrogenation of the CO bond, while the addition of ammonia water reduced the competitiveness of cyclopentanone direct hydrogenation. The by-products in the reaction system were determined, and the reaction network was proposed. Combined with the curve of cyclopentanone conversion-product yield-time, the reaction pathway was speculated. The cyclopentanone self-condensation reaction was catalyzed by NiO-Co₃O₄/TiO₂ at the initial stage of the reaction. Hydrogenation products appeared at a reaction time of 20–30 min, and the yield of 2-cyclopentenylcyclopentanone increased first and then decreased. Combined with XRD and XPS analyses, the valence states of metals were determined.

The decarboxylation (of mixtures) of short-chain carboxylic acids (C₂ and C₃) on oxidized platinum anodes was investigated using constant current and galvanic square-wave pulse electrolysis. At constant current, a high ethylene to ethane product ratio indicates that propionate is the substrate of preferential decarboxylation in propionate/acetate mixtures, depending on the feed ratio. The specificity of (oxidized) Pt electrodes towards C₃ decarboxylation can be further enhanced by the application of cathodic and anodic pulses. The application of relatively long cathodic pulses and very short anodic pulses has been demonstrated to facilitate the formation of high ethylene to ethane ratio product mixtures, which are higher than those obtained under constant current conditions. In particular, extended cathodic pulses have been observed to enhance the faradaic efficiency towards oxygen and to reduce carboxylate conversion. Based on isotherm and RRDE data, we propose that the selectivity for propionate is attributable to a higher affinity for the oxidized Pt electrode, which is further enhanced by cathodic and anodic pulses. The use of galvanic square wave-pulse electrolysis thus offers a promising pathway for the efficient conversion of bio-derived acids into fuels and chemicals.

Methanol, as a promising liquid hydrogen carrier, has attracted considerable interest in sustainable energy applications due to its renewability and ease of storage and transportation. Although methanol steam reforming for hydrogen production has been extensively studied, it faces several challenges, including high energy consumption at elevated temperatures, low hydrogen purity, and substantial CO₂ emission. We propose a four-step H₂ absorption-enhanced methanol steam reforming method that includes reforming/absorption, vapor purge, vacuum desorption, and pressurization steps. A two-dimensional, axisymmetric transient numerical model is developed, accounting for flow, heat transfer, mass transfer, chemical reactions, and hydrogen absorption/desorption. All components of the established model, including methanol steam reforming and H₂ absorption/desorption, are separately validated through experimental data, confirming the reliability of the model. Results indicate that under baseline conditions of 463 K and 3 bar, the reforming/absorption step achieves a methanol conversion of 98.88% and a hydrogen production rate of 0.87 mmol g⁻¹ min⁻¹, representing an improvement of 17.43 percentage points and 0.17 mmol g⁻¹ min⁻¹ compared with conventional methanol steam reforming, respectively. Additionally, a CO₂ stream with a concentration of 98.87% is obtained from the reactor outlet, which is comparable to the concentrations achieved by specialized CO₂ capture technologies and can be directly sequestered or reused. In the four-step cycle, incorporating the vapor purge enhances hydrogen purity, achieving levels exceeding 99.9%, compared with only 96.89% purity in the direct vacuum desorption method. Moreover, the four-step method obtains a hydrogen recovery rate of 98.92%. The proposed method provides a clean, straightforward, and highly integrated approach to sustainable hydrogen production and presents a novel option for accelerating the decarbonization of fossil fuel-dominated energy systems.

Hydrogen is a vital and significant alternative fuel that can play a major role in reducing the impact of climate change. Developing robust and highly active bifunctional catalysts is essential for achieving sustainable electrolytic hydrogen generation. The electrocatalysts used for the OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) are prone to corrosion, particularly under alkaline conditions. Developing engineering solutions to provide stability while maintaining activity of RuO₂ as a bifunctional catalyst remains a significant and major problem. In this study, we present a hierarchical heterostructure synergy effect that was generated through a straightforward electrode fabrication method, as opposed to a highly intensive and extremely challenging chemical synthesis route where heat-treated α-MnO₂ (referred to as 400-α-MnO₂) is used as an interlayer for RuO₂. With the help of detailed EIS and XPS analysis, we observed that the presence of 400-α-MnO₂ creates an unobstructed channel for electron transfer to RuO₂, resulting in improved activity towards both the OER and HER, as well as increased durability. The heterojunction catalyst has also been evaluated in an AEM-based full cell, which exhibits remarkable stability and activity with a minimal RuO₂ mass loading of 189 μg cm⁻². The proposed engineered interface, using 400-α-MnO₂, surpasses the stability and activity limitations of RuO₂ in an alkaline environment.

As one of the most successful inorganic materials, MFI zeolite has been widely used in petrochemical and fine chemical industries. However, the presence of only micropores in MFI zeolite creates diffusion barriers and thus precludes its usage in processes involving large substrates. It is highly desirable to mitigate the diffusion pathways in MFI zeolites. One of the efficient methods is the morphology control strategy, which has become a hot topic in the past few decades. In this review, we summarize the progress of MFI zeolite morphology control using specific organic additives as morphology modifiers to enhance the catalytic and separation performance. Organic additives, including urea, amino acids, small organic molecules, and polymers, were categorized based on the MFI zeolites induced by them. The morphologies generated can be classified as nanocrystals, aggregated nanoparticles, nanosheets, intergrown nanosheets, plates, intergrown plates, needles, and bulky prismatic crystals, depending on the specific additives. The formation mechanisms of different morphological MFI zeolites and their properties are also discussed. This review is of great importance for the controllable synthesis of zeolites and rational design of zeolite catalysts.