Sustainable Energy & Fuels最新文献

Robust alkali-resistant cobaltocenium-containing poly(carbazole)s are prepared via the combination of superacid-catalyzed polyhydroxyalkylation and CuAAC-based post-polymerization modification. The prepared cobaltocenium-containing AEMs show a hydroxide conductivity of up to 127.2 mS cm⁻¹ at 80 °C and a conductivity retention of more than 95.0% after soaking in 1 M NaOH for 2500 h.

This study explores the enhancement of hydrogen production via dry reforming of methane (DRM) using nickel catalysts supported on metalized silica-alumina. By incorporating noble metals (Ir, Pd, Pt, Ru, and Rh), we significantly improve the catalysts' reducibility, basicity, and resistance to coke deposition. Our novel approach integrates a predictive model combining advanced statistical and experimental techniques to optimize catalyst performance. The active site population derived from the reduction of the NiAl₂O₄ phase is found to be stable and least affected under oxidizing gas stream (CO₂) as well as reducible gas stream (H₂) during the DRM reaction. The catalyst system is characterized by surface area and porosity, X-ray diffraction, Raman spectroscopy, thermogravimetry analysis, XPS, TEM, and various temperature-programmed reduction/desorption techniques (TPR/CO₂-TPD). Notably, the 5Ni/1IrSiAl catalyst shows reduced activity due to low reducibility and basicity, whereas the 5Ni/1RhSiAl catalyst demonstrates superior performance, achieving a hydrogen yield of 62% at 700 °C and 80% at 800 °C after 300 minutes. This enhancement is attributed to the highest edge of reducibility, the maximum concentration of stable active sites “Ni” (derived from NiAl₂O₄ during the DRM reaction), and the optimum concentration of moderate strength basic sites. Through the application of multiple response surface methodology and central composite design, we developed a predictive model that forecasts the optimal conditions for maximizing hydrogen yield, which was experimentally validated to achieve 95.4% hydrogen yield, closely aligning with the predicted 97.6%. This study not only provides insights into the mechanistic pathways facilitated by these catalysts but also demonstrates the efficacy of computational tools in optimizing catalytic performance for industrial applications.

The combined hydrolysis–deoxygenation method reported here demonstrates the efficiency of hydrogen-free catalytic conversion of lipid-derived multi-fatty acids into renewable drop-in hydrocarbon biofuels. Using a 5 wt% Pt on carbon (5 wt% Pt/C) catalyst for a detailed deoxygenation study, experiments were conducted in a batch reactor under nitrogen atmosphere at various temperatures (350–400 °C), reaction times (0–3 h) and catalyst/feedstock mass ratios (0–0.2). The Pt/C catalyst showed remarkable selectivity towards the decarboxylation mechanism, as evidenced by substantial CO₂ formation. The Pt/C-catalysis optimal conditions were: 400 °C, 2 h reaction time and a catalyst/feedstock mass ratio of 0.2, resulting in a yield of 3.76 wt% gasoline, 14.7 wt% kerosene and 53.7 wt% diesel range hydrocarbons. Under the set of optimal conditions, five other catalysts with different supports were tested and the results showed that 5 wt% Pt/MgSiO₃ and 5 wt% Pt/Al₂O₃ catalysts enabled complete conversion of fatty acids (total acid number = 0 mg KOH g⁻¹). In contrast, 5 wt% Pt/SiO₂, 5 wt% Pd/MgSiO₃ and bimetallic 10 wt% Ni–Cu/Al₂O₃ performed poorly, indicating the effects of both the active metal and metal–support interaction on the conversion of fatty acids. In all cases, the oil products were dominated by heptadecane, originating from decarboxylation and in situ hydrogenation of the dominant oleic acid (74.4 wt%) and other C₁₈ fatty acids present in the hydrolysed feedstock. Visually, only the Pt/C catalyst produced light-coloured liquids with direct-use fuel appeal, possibly due to its mildly acidic nature and comparably much larger surface area of 650 m² g⁻¹.

The use of eco-unfriendly materials in wearable electronic devices poses a serious threat to the environment. It is therefore crucial to develop flexible, wearable devices that are environmentally friendly and safe for human skin. To power such devices, miniaturized power sources are needed, such as metal–air batteries (MABs) that have excellent power density and longevity. However, traditional MABs are built on rigid, non-flexible platforms and use a large amount of electrolyte, which is not sustainable or suitable for flexible electronics. Green wearable MABs can be created by using biocompatible and biodegradable battery components, such as electrolytes, electrodes, and flexible platforms, or by reducing the electrolyte volume. In this review, we critically examine a range of cost-effective, downsized, green, and sustainable wearable MABs that use non-toxic and abundant natural materials and can withstand bending, twisting, stretching, and folding. The various components, their green and sustainable aspects and the synthesis approaches of the key air-cathode have been demonstrated in detail. The electrochemical performance of various green MABs, as well as the obstacles to their commercialization has also been discussed.

The two-electron oxygen reduction reaction (ORR), powered by affordable renewable energy, presents a more promising and sustainable approach to hydrogen peroxide production than traditional methods. In this study, we introduce a membrane electrolyzer for ORR-to-H₂O₂ generation. The conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) acts as the cathode that aids the oxygen reduction reaction through a two-electron pathway to produce H₂O₂. At the anode, we employed the oxidation of a model organic molecule, 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt monohydrate (tiron). This catalyst-free anode process, as an alternative to the sluggish water oxidation reaction commonly used in classical electrolyzers, reduces voltage loss to release protons, cross the membrane, and feed the ORR at the cathode. Our study investigated the often-neglected issue of organic crossover during electrolyzer operation and its significant impact on transport behavior. This research paves the way for the development of crossover-free flow cells, extending the realm of electrochemical devices based on the electrolyte fed and the membrane.

Power generation from natural evaporation receives great attention as water evaporation is a ubiquitous process. However, the energy devices may not have the normal geometry that results in different flow and energy conversion behaviors. Here, a conical polytetrafluoroethylene (PTFE) hydrovoltaic generator with asymmetric electrodes is proposed to study the effect of membrane structure and electrode matching on power generation. An asymmetric membrane structure optimizes the capillary flow that generates a more effective velocity in the top areas of the generator, which induces a higher voltage sign. Meanwhile, the directed asymmetric electrodes synergize interfacial and streaming potentials. As a result, the forward conical structure with C–Cu electrodes obtains the optimal energy conversion performance. Subjecting such a device to environmental conditions, it can induce a ∼0.4 V open circuit voltage and remain stable for around 20 hours without noticeable fluctuations. The facile structure and electrode matching optimizes the power generation, providing valuable insights into sustainable energy harvesting.

The tailored development of highly active and selective electrocatalysts based on abundant and non-toxic elements will be key to the rigorous implementation of sustainable processes in industry. In this context, spinel-type CuFe₂O₄ is regarded as a promising candidate. We synthesised CuFe₂O₄ nanoparticles with various Cu : Fe ratios via a microwave-assisted solvothermal route. The compositional effect on the material properties and performance in multiple electrochemical reactions, including HER, OER, ORR and CO₂RR, is investigated, in order to obtain valuable insights about those parameters that drive the improvement of catalytic activities. An increase in lattice strain and surface area is observed for compositions deviating from the ideal 1 : 2 stoichiometry, which goes in hand with an improved performance in alkaline water splitting. For the CO₂RR on the other hand, the Cu-content is determined to be the most important factor, with a Cu-excess being highly beneficial. The suitability of CuFe₂O₄ as a bifunctional water splitting catalyst was demonstrated by full cell measurements using the spinel catalyst at both the anode and cathode side at the same time. Moreover, we showed the applicability of CuFe₂O₄ in bifunctional gas-diffusion electrodes for rechargeable Zn–air batteries.

MXenes are unique two-dimensional nanomaterials and have the advantages of large interlayer spacings and conductive layered structures, providing great potential for enhancing the electrochemical properties of supercapacitors. However, van der Waals forces may cause the re-stacking of sheets in MXenes, which further reduces the specific surface area and restricts the transport of ions/electrolytes within the electrode, thus resulting in an unfavorable electrochemical performance. In this paper, a heteropoly acid was used as a dopant to oxidize pyridine for the preparation of conductive polypyridine (PPY). By doping MXene with PPY, the resulting MXene/PPY composite exhibits significant advantages for averting the self-stacking of the MXene nanosheets induced by van der Waals forces, promoting electron migration, and the improving specific capacitance. Under the synergistic effect of the highly conductive MXene and electrochemically active PPY, a symmetric supercapacitor fabricated from MXene/PPY attains an energy density of 8.77 W h kg⁻¹ at a power density of 750 W kg⁻¹. More importantly, the supercapacitor maintains a capacity retention rate of 75% after 4000 cycles of continuous charging and discharging. The favorable energy density and power density, along with its excellent electrochemical stability, suggest that the fabricated MXene/PPY composite has considerable potential for practical applications.

The development of a high-rate capability and long cycling life cathode material for Zn-ion batteries is significantly limited due to the low electrical conductivity of the cathode material. Herein, we have developed a high-capacity and highly stable promising cathode material for Zn-ion batteries by directly growing CuV₂O₆ nanowires on 2D-V₂CT_x MXene nanosheets. This composite architecture exhibits faster charge diffusion and increased electrical conductivity, which leads to better rate performance and longer cycling life. The CuV₂O₆–V₂CT_x nanohybrid displays a high specific capacity of 410 mA h g⁻¹ at 0.1C rate and a long cycle stability of 1000 cycles at 0.5C rate with a capacity retention of 88% when compared to the pristine CuV₂O₆ nanowires (329 mA h g⁻¹ at 0.1C rate). In addition, the cathode material exhibits a high energy density of 302 W h kg⁻¹ at a power density of 173 W g⁻¹. This work provides new views and findings for the development of superior cathode materials for aqueous Zn-ion batteries.

Wind power will meet nearly 20% of the global energy demand by 2050, and the forecasted increase in wind power capacity combined with the proximate end-of-life (EoL) of existing infrastructures will pose a significant challenge. While the volumes of wind blade composite waste materials are expected to increase rapidly, there are no circular solutions available in the market to address this issue, and unlock new value chains for wind blade composite recyclates. This perspective aims to discuss the reported strategies for chemical recycling of fiber-reinforced composites, highlighting limitations for upscaling and offering the author's vision on novel technologies to enhance the process feasibility. Current issues associated with the increasing production of dismantled EoL wind turbine blade composite materials (WBCMs) are introduced and the regulatory framework is reviewed, addressing the common challenges associated with structural composite materials and their recyclability. The main novel recycling technologies for WBCMs (mechanical and, especially, chemical recycling) are evaluated based on the literature published between 2019 and 2024, discussing the value of recycled products, new value-added applications, and their circularity and sustainability aspects. The current barriers for industrialization are presented and serve as an introduction to the concept of microwave technology as an alternative and complementary technology for enhancing chemical recycling processes. Lastly, the main findings and limitations of chemical recycling of WBCMs using microwave-assisted technologies are summarized and proposals for future research are presented, highlighting a much-needed development of industrial circular solutions.