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The oxygen reduction reaction (ORR), a pivotal process in hydrogen fuel cells crucial for enhancing fuel cell performance through suitable catalysts, remains a challenging aspect of development. This study explores the catalytic potential of germanene on Al (111), taking advantage of the successful preparation of stable reconstructed germanene layers on Al (111) and the excellent catalytic performance exhibited by germanium-based nanomaterials. Through first-principles calculations, we demonstrate that the O2 molecule can be effectively activated on both freestanding and supported germanene nanosheets, featuring kinetic barriers of 0.40 and 0.04 eV, respectively. The presence of the Al substrate not only significantly enhances the stability of the reconstructed germanene but also preserves its exceptional ORR catalytic performance. These theoretical findings offer crucial insights into the substrate-mediated modulation of germanene stability and catalytic efficiency, paving the way for the design of stable and efficient ORR catalysts for future applications. [ABSTRACT FROM AUTHOR]

The proton transport in one-dimensional (1D) confined water chains has been extensively studied as a model for ion channels in cell membrane and fuel cell. However, the mechanistic understanding of the proton transfer (PT) process in 1D water chains remains incomplete. In this study, we demonstrate that the two limiting structures of the hydrated excess proton, H5O2+ (Zundel) and H3O+ (linear H7O3+), undergo a change in dominance as the water chain grows, causing two co-existing and opposing PT mechanisms. Specifically, H5O2+ is stable in the middle of the chain, whereas H3O+ serves as a transition state (TS). Except for this region, H3O+ is stabilized while H5O2+ serves as a TS. The interaction analysis shows that the electrostatic interaction plays a crucial role in the difference in PT mechanisms. Our work fills a knowledge gap between the various PT mechanisms reported in bulk water and long 1D water chains, contributing to a deeper understanding of biological ion channels at the atomic level. [ABSTRACT FROM AUTHOR]

Multiscale design of catalyst layers (CLs) is important to advancing hydrogen electrochemical conversion devices toward commercialized deployment, which has nevertheless been greatly hampered by the complex interplay among multiscale CL components, high synthesis cost and vast design space. We lack rational design and optimization techniques that can accurately reflect the nanostructure-performance relationship and cost-effectively search the design space. Here, we fill this gap with a deep generative artificial intelligence (AI) framework, GLIDER, that integrates recent generative AI, data-driven surrogate techniques and collective intelligence to efficiently search the optimal CL nanostructures driven by their electrochemical performance. GLIDER achieves realistic multiscale CL digital generation by leveraging the dimensionality-reduction ability of quantized vector-variational autoencoder. The powerful generative capability of GLIDER allows the efficient search of the optimal design parameters for the Pt-carbon-ionomer nanostructures of CLs. We also demonstrate that GLIDER is transferable to other fuel cell electrode microstructure generation, e.g., fibrous gas diffusion layers and solid oxide fuel cell anode. GLIDER is of potential as a digital tool for the design and optimization of broad electrochemical energy devices.

Protrusions can be used to improve the transport processes involved, but the causes of the phenomena are still incompletely understood. Computational fluid dynamics analyses are performed under different sets of circumstances to gain insights into the physics of heat and mass transfer processes in a protruded millisecond microchannel reactor, wherein a steam reforming reaction is proceeding and protrusions are used to improve the transport processes involved. Recommendations are made on how to optimize design for better reactor performance. Particular emphasis is placed on delineating the role of methanol-air equivalence ratio and channel length in reactor performance. The results indicate that the equivalence ratio and channel length must be adjusted as needed to minimize pressure drops and maximize production of hydrogen. Necessary adjustments to the equivalence ratio of methanol to air can be made to control the maximum reactor temperature within certain needed limits. The short-channel design may be preferred over the long-channel design in order to simultaneously achieve low pressure drops and sufficiently high conversions in the reactor. Expectable compromises have to be made between hydrogen productivity and pressure drop.

Flow of a fluid past a body is a very complicated phenomenon. Computational fluid dynamics is used for studying the characteristics of flow past an array of hemispherical protrusions that is disposed on the wall surfaces of a millisecond microchannel reactor. Protrusions can be used to improve the transport processes involved, but the causes of the phenomena are still incompletely understood. Parametric analyses are performed under different sets of circumstances to delineate the role of geometric features and operation conditions in reactor performance. Dimensionless quantities are used to simplify the characterization of the reactor system with multiple interacting transport phenomena. The mechanisms involved in the intensified processes are analysed, and performance improvement recommendations are presented. The results indicate that the protruded reactor behaves effectively and good yields can be obtained with only milliseconds residence of the mixtures within the channels. The reactor offers the unique advantage for hydrogen production from methanol in that process intensification is realized while preserving the energy balance between the exothermic and endothermic processes. However, the flow rates must be adjusted as needed to maximize production of hydrogen and minimize pressure drops. The momentum diffusivity is more dominant around the protrusion regions than in the other regions. The thermal diffusivity is more dominant in the protruded channels than in the flat channels. The results have implications for hydrogen production and beyond for the study of transport phenomena in microchemical systems.

Homogeneous solar fuels photocatalytic systems often require several additives in solution with the catalyst to operate, such as a photosensitizer (PS), Brønsted acid/base, and a sacrificial electron donor (SED). Tertiary amines, in particular triethylamine (TEA) and triethanolamine (TEOA), are ubiquitously deployed in photocatalysis applications as SEDs and are capable of reductively quenching the PS's excited state. Upon oxidation, TEA and TEOA form TEA•+ and TEOA•+ radical cations, respectively, which decay by proton transfer to generate redox non-innocent transient radicals, TEA• and TEOA•, respectively, with redox potentials that allow them to participate in an additional electron transfer step, thus resulting in net one-photon/two-electron donation. However, the properties of the TEA• and TEOA• radicals are not well understood, including their reducing powers and kinetics of electron transfer to catalysts. Herein, we have used both pulse radiolysis and laser flash photolysis to generate TEA• and TEOA• radicals in CH3CN, and combined with UV/Vis transient absorption and time-resolved mid-infrared spectroscopies, we have probed the kinetics of reduction of the well-established CO2 reduction photocatalyst, fac-ReCl(bpy)(CO)3 (bpy = 2,2′-bipyridine), by these radicals [kTEA• = (4.4 ± 0.3) × 109 M−1 s−1 and kTEOA• = (9.3 ± 0.6) × 107 M−1 s−1]. The ∼50× smaller rate constant for TEOA• indicates, that in contrast to a previous assumption, TEA• is a more potent reductant than TEOA• (by ∼0.2 V, as estimated using the Marcus cross relation). This knowledge will aid in the design of photocatalytic systems involving SEDs. We also show that TEA can be a useful radiolytic solvent radical scavenger for pulse radiolysis experiments in CH3CN, effectively converting unwanted oxidizing radicals into useful reducing equivalents in the form of TEA• radicals. [ABSTRACT FROM AUTHOR]

Polymer membrane electrolyzers are a useful tool for producing hydrogen, which is a renewable energy source. Unmanned aerial vehicle (UAV) fuel cells can be powered by the hydrogen and oxygen produced by the electrolyzer. The primary losses of polymer membrane electrolyzers must therefore be identified in order to maximize their performance. A renewable-based multi-energy system considers power, cooling, heating, and hydrogen energy as utility systems for integrated sport buildings. In this study, we investigate the effect of radiation intensity, current density, and other performance factors on the rate of hydrogen production in water electrolysis using a polymer membrane electrolyzer in combination with a solar concentrator. The findings showed that a rise in hydrogen generation led to an increase in current density, which increased the electrolyzer's voltage and decreased its energy and exergy efficiencies. The voltage was also increased, and the electrolyzer's efficiency was enhanced by a rise in temperature, a decrease in pressure, and a reduction in the thickness of the nafion membrane. Additionally, with a 145% increase in radiation intensity, hydrogen production increased by 110% while the electrolyzer's energy and exergy efficiencies decreased by 13.8% as a result of the electrolyzer's high input electric current to hydrogen output ratio. [ABSTRACT FROM AUTHOR]

Small-sized fuel cell is an ideal and promising power source for portable devices due to its long-term electricity supply and free of CO 2 emission. However, its commercialization is obstructed by reliable hydrogen source, which should be non-corrosiveness, as compact as possible, stable and controllable high purity hydrogen supply. In this study, a novel in situ hydrogen production material Al/BiCl 3 /γ-Al 2 O 3 composite is synthesized, which exhibits high hydrogen yield, fast hydrogen production rate and outstanding storage stability. The hydrogen production performance of Al/BiCl 3 /γ-Al 2 O 3 can be adjusted by changing BiCl 3 :γ-Al 2 O 3 weight ratio, additive content and milling time. XRD and SEM results indicate that surface cracks, active surface and metal Bi produced in fabrication process lead to the high hydrolysis activity of Al/BiCl 3 /γ-Al 2 O 3. Mechanism analyses reveal that hydrogen production process is the results of pitting, microgalvanic effect and catalytic effect. Taking into account hydrogen production performance, capacity and cost, Al/5 wt%BiCl 3 /5 wt%γ-Al 2 O 3 milled for 2 h is a potential hydrogen production material, which can in situ supply hydrogen for small-sized fuel cell. [Display omitted] • A novel in situ hydrogen production material Al/BiCl 3 /γ-Al 2 O 3 was synthesized. • Al/BiCl 3 /γ-Al 2 O 3 has no induction time and high hydrogen production rate and yield. • Hydrolysis activity relies on BiCl 3 :γ-Al 2 O 3 ratio, additive content and milling time. • Al/BiCl 3 /γ-Al 2 O 3 composite exhibits excellent storage stability. • Pitting, microgalvanic effect and catalytic effect are the hydrolysis mechanisms. [ABSTRACT FROM AUTHOR]

The distribution of relaxation times (DRT) method is an efficient approach for analyzing electrochemical impedance spectroscopy (EIS) of fuel cells. However, facing electrochemical processes with close characteristic times/frequencies, low frequency resolution of DRT puts a damper on the analysis of results. To address this problem, a new DRT method integrating elastic net regularization and quantum particle swarm optimization (QPSO) algorithm is proposed in this study. Elastic net regularization combines the advantages of Lasso's feature selection and Tikhonov's coefficient shrinkage, thereby enhancing the frequency resolution of DRT. The use of the QPSO algorithm avoids the manual selection of parameters. A comprehensive evaluation of the developed method is conducted using both synthetic EIS and experimental EIS. The results show that the developed DRT method shows good performance and the reconstructed DRT functions exhibit high frequency resolution and accuracy. Overall, the proposed DRT method holds promise for advancing the characterization of fuel cells. • A DRT method integrating elastic net regularization and QPSO algorithm is proposed. • The developed DRT method exhibits good performance in frequency resolution. • The developed DRT is free of adjusting parameters. [ABSTRACT FROM AUTHOR]

Ceria-based electrolyte materials are of great interest for solid oxide fuel cell applications because they exhibit low ohmic resistance and high ionic conductivity, especially at a low temperature of 550oC. Consequently, we have designed a very interesting electrolyte Al and Nd dual-doped SDC (Sm 0.1 Ce 0.9 O 2) using the sol–gel technique to function as an electrolyte for LT–CFCs (low-temperature ceramic fuel cells). The AN–SDC (Al 0.15 N 0.15 -Sm 0.1 Ce 0.6 O 2) as an electrolyte shows a maximum power output of 1085 mW/cm2 with a high ionic conductivity of 0.22 S/cm at 550oC. This high performance is mainly because of the co-doping into SDC, which facilitates many oxygen vacancies, enabling faster stabilized ion transportation through the AN–SDC lattice. The low resistance of either the ohmic and grain boundary resistance + the microstructure features of AN–SDC contribute to achieving higher fuel cell performance. In addition, dual doping into SDC might build a synergistic effect, which further improves devices' performance. The ionic conduction mechanism has been explained based on the dual doping of the incorporation of Al and Nd into the SDC. Dual doping is a promising, feasible avenue for designing electrolytes to enhance the performance of LT–CFC devices. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous PEDOT as the support of PdSn nanoalloy electrocatalyst. • Pd 4 Sn 6 /PEDOT is created and used for the oxidation of ethylene glycol and ethanol. • The interface electronic structure of Pd was modified by introducing Sn and PEDOT. • It shows outstanding electrocatalytic performance and poisoning-tolerance ability. Developing a novel catalyst with lower noble-metal loading and higher catalytic efficiency is significant for promoting the widespread application of direct alcohol fuel cells (DAFCs). In this work, poly(3,4-ethylenedioxythiophene) (PEDOT) supported the PdSn alloy (PdSn/PEDOT) were simply synthesized and their electrocatalytic performance toward the oxidation of ethylene glycol and ethanol (EGOR and EOR) were investigated in alkaline media, respectively. In comparison with other control catalysts, the optimized Pd 4 Sn 6 /PEDOT catalyst exhibits the highest mass activity (7125/4166 mA mg Pd −1) and specific activity (26/15 mA cm−2) towards EGOR/EOR. The mass activity of Pd 4 Sn 6 /PEDOT for EGOR and EOR are 11.9 and 10.9 times higher than commercial Pd/C, respectively. Moreover, chronoamperometry (CA) and successive cyclic voltammetry (CV) tests show that the CO resistance ability and durability of the Pd 4 Sn 6 /PEDOT catalyst were superior to Pd 4 Sn 6 , Pd/PEDOT and commercial Pd/C catalysts, which can be attributed to the d-band center of Pd can be effectively downshifted and the interface strain effect between electrons caused by the conjugated structure between PEDOT groups. This work provides an effective strategy for the development of highly efficient anode catalysts of DAFCs. [ABSTRACT FROM AUTHOR]

Y-doped BaZrO 3 is a well-researched material for proton-conducting fuel cells. One of the main limitations is the very high sintering temperature (∼ 1600 °C) necessary to densify the material. As Ba is lost at this temperature due to BaO evaporation, the stoichiometry is changed uncontrollably. This study is focused on evaluating the influence of slight changes in stoichiometry on microstructure, chemical stability, and conductivity of 20% Y-doped BaZrO 3 (BZY20) as well as 10% Y- and 10% Sc-co-doped BaZrO 3 (BZY10Sc10). Overall, Ba excess resulted denser microstructures with larger grains. Still, these samples were prone to decomposition by forming BaCO 3. Therefore, a slight Ba deficiency is favorable as the conductivity did not suffer in the examined stoichiometry region. [ABSTRACT FROM AUTHOR]

To resolve the issue of predicting the leak rate in proton exchange membrane fuel cells (PEMFCs) under long-term random vibration conditions. Considering the mechanism of bolt vibration loosening and rubber vibration relaxation, a leakage mechanism model of the PEMFC sealing structure under vibration conditions is proposed, and the validity of the model is verified by experimental comparison. The model clearly reveals the quantitative effects of structural parameters and material parameters on the leakage rate of PEMFC under vibration conditions. The research results show that under long-term random vibration conditions, the change of PEMFC leakage rate with time is mainly divided into three stages: response stage, stable stage, and leakage stage. Compared to bolt vibration loosening, the rubber vibration relaxation has a more significant impact on PEMFC leakage, the leakage rate of the fuel cell stack is 433ppm after 10,000 hrs of vibration. In addition, increasing the bolt preload, changing the bolt distribution, reducing surface roughness, and reducing gasket thickness can effectively suppress PEMFC leakage under random vibration conditions, the minimum leakage rate of the fuel cell stack can be reduced to around 170ppm per 10,000 hours. The proposed mechanism model provides an effective method for predicting the leakage rate of PEMFC sealing structures. [ABSTRACT FROM AUTHOR]

In this paper, a new method is designed to effectively determine the parameters of proton exchange membrane fuel cells (PEMFCs), i.e., ξ 1 , ξ 2 , ξ 3 , ξ 4 , R C , λ , and b . The fuel cells (FCs) involve multiple variable quantities with complex non-linear behaviours, demanding accurate modelling to ensure optimal operation. An accurate model of these FCs is essential to evaluate their performance accurately. Furthermore, the design of the FCs significantly impacts simulation studies, which are crucial for various technological applications. This study proposed an improved parameter estimation procedure for PEMFCs by using the GOOSE algorithm, which was inspired by the adaptive behaviours found in geese during their relaxing and foraging times. The orthogonal learning mechanism improves the performance of the original GOOSE algorithm. This FC model uses the root mean squared error as the objective function for optimizing the unknown parameters. In order to validate the proposed algorithm, a number of experiments using various datasets were conducted and compared the outcomes with different state-of-the-art algorithms. The outcomes indicate that the proposed GOOSE algorithm not only produced promising results but also exhibited superior performance in comparison to other similar algorithms. This approach demonstrates the ability of the GOOSE algorithm to simulate complex systems and enhances the robustness and adaptability of the simulation tool by integrating essential behaviours into the computational framework. The proposed strategy facilitates the development of more accurate and effective advancements in the utilization of FCs. [ABSTRACT FROM AUTHOR]

Medium-temperature proton exchange membrane fuel cells (MT PEMFCs) operating at 100° to 120°C have improved kinetics, simplified thermal and water management, and broadened fuel tolerance compared with low-temperature PEMFCs. However, high temperatures lead to Nafion ionomer dehydration and exacerbate gas transportation limitations. Inspired by osmolytes found in hyperthermophiles, we developed a-aminoketone– linked covalent organic framework (COF) ionomers, interwoven with Nafion, to act as “breathable” proton conductors. This approach leverages synergistic hydrogen bonding to retain water, enhancing hydration and proton transport while reducing oxygen transport resistance. For commercial Pt/C, the MT PEMFCs achieved peak and rated power densities of 18.1 and 9.5 Watts per milligram of Pt at the cathode at 105°C fueled with H2 and air, marking increases of 101 and 187%, respectively, compared with cells lacking the COF. [ABSTRACT FROM AUTHOR]

Insufficient catalytic activity and stability of oxygen electrodes are major challenges for the widespread use of reversible solid oxide cells (Re‐SOCs). Here, a Ruddlesden‐Popper‐structured high‐entropy La1.4Sr0.6Co0.2Fe0.2Ni0.2Mn0.2Cu0.2O4±δ (RP‐LSCFNMC) oxygen electrode with fast oxygen reduction and emission reaction kinetics, inhibited Sr segregation and favorable thermal expansion efficient is reported. A Re‐SOC with the RP‐LSCFNMC oxygen electrode achieves an encouraging peak power density of 1.74 W cm−2 in the fuel cell mode and a remarkable current density of 2.10 A cm−2 at 1.3 V in the water electrolysis mode at 800 °C. The Re‐SOC also shows excellent stability, with no Sr segregation observed after 120 h of testing in both the fuel cell and electrolysis modes at 750 °C. Furthermore, the improved activity and stability of the RP‐LSCFNMC oxygen electrode are confirmed through a combination of experiments and density functional theory‐based calculations. These findings make the high‐entropy RP‐LSCFNMC oxide a promising oxygen electrode candidate for advanced Re‐SOCs. [ABSTRACT FROM AUTHOR]

Proton exchange membranes with high selectivity are urgently required in energy and electronic technologies. Although Nafion represents the state‐of‐the‐art commercial proton exchange membrane material,it still suffers from the permeation of undesirable substances, like hydrogen in fuel cells and vanadium ions in redox flow batteries, due to the unmatched sizes between its ionic domains (3–5 nm) and these substances. In this work, we present a supramolecular modification strategy that simultaneously enhances the proton conductivity and selectivity of Nafion. We employ fluoroalkyl‐grafted polyoxometalate (POMs) nanoclusters as supramolecular additives to modify Nafion via co‐assembly. These POMs can precisely and robustly decorate at Nafion ionic domains, with their fluoroalkyl chains anchoring into the perfluorinated matrix while their inorganic clusters stay in the ionic regions. The hybrid membranes, with continuous proton hopping sites and nanoscale steric hindrance offered by POMs, exhibit a 56 % increase in proton conductivity and a 100 % improvement in proton/vanadium selectivity. This leads to significantly enhanced power density and energy efficiency in fuel cells and vanadium flow batteries, respectively. These results underscore the intriguing potential of molecular cluster additives in improving the functions of ion‐conducting membranes. [ABSTRACT FROM AUTHOR]

As a power generation fuel, high-pressure hydrogen gas is widely used in transportation, and significantly contributed to development of hydrogen fuel cell electric vehicles. However, obvious temperature rise generated during fast refueling causes serious safety risk to reliable operation of fuel cell stacks. Therefore, it is necessary to conduct in-depth research on fast filling process. Based on safety reasons, the SAE J2601/ISO 15869 strictly regulates the maximum temperature limit of 85 °C in specifications for refueling hydrogen gas tanks. In this study, a 70 MPa, Type IV on-board hydrogen storage tank is adopted as the research object, and a 2-dimensional axisymmetric numerical model is established to study the temperature rise of the vapor within storage tanks during fast refueling. The Realizable k - ε turbulence model is employed to simulate high intensity turbulent fluctuation during fast filling. Considering the compressibility of vapor, the state of equation for real hydrogen gas is used by obtaining fluid thermodynamic properties from the National Institute of Standards and Technology database. Three groups of fast filling experiments are selected to validate the developed numerical model. The comparison result shows that the numerical model has good prediction ability on hydrogen fast refueling. The final mass average temperature differences between numerical results and experimental data are 2.6 K, 4.3 K, and 0.03 K, respectively. Based on the developed numerical model, the influences of structure parameters and material properties on the temperature rise of hydrogen storage tanks are investigated. The results indicate that the inlet diameter and wall thickness of the inner and outer layers of the storage tank have weaken impacts on the temperature rise during rapid charging, with the maximum temperature differences of 1.8 K, 0.74 K, and 0.54 K, respectively. Due to the influence of heat capacity, the material properties of different layers exhibit a similar variation trend. This work can deepen researchers' understanding of the temperature rise of on-board hydrogen storage tanks during fast filling, and provide technical references for the structural optimal design of tanks and rapid refueling at hydrogen stations. • A 2-dimensional axisymmetric numerical model is constructed to predict the temperature rise during rapid charging. • Different structural parameters and material properties on the temperature rise performance are specially investigated. • Effects of inlet pipe diameter and wall thickness on the thermal behavior of hydrogen storage tanks are not so obvious. • The material properties of liner and laminate of storage tanks cause obvious impacts on the temperature rise control. [ABSTRACT FROM AUTHOR]

A Sr-deficiency approach is utilized to adjust the composition of the standard Sr 2-x Fe 1.5 Mo 0.25 Sc 0.25 O 6 (SFMS) material, with the goal of improving the performance of the SFMS cathode in proton-conducting solid oxide fuel cells (H–SOFCs). The Sr-deficiency concentration is restricted to 10% at the Sr site, and an increase in Sr-deficiency leads to the formation of more oxygen vacancies. However, the presence of increased oxygen vacancies does not consistently enhance the diffusion capabilities of charge carriers. The excess of oxygen vacancies impedes the movement of oxygen and protons. The optimal oxygen and proton transport capabilities are achieved when the Sr-deficiency level is set at 5%. Specifically, this is observed in the compound Sr 1.9 Fe 1.5 Mo 0.25 Sc 0.25 O 6 (S1.9FMS). The enhanced oxygen and proton diffusion kinetics enable H–SOFCs to achieve exceptional performance when employing the S1.9FMS cathode, reaching a power density of 1709 mW cm−2 at 700 °C with a low polarization resistance of 0.023 Ω cm2. The fuel cell's output exceeds that of many previously reported H–SOFCs. Furthermore, the fuel cell utilizing the S1.9FMS cathode not only exhibits excellent fuel cell performance but also maintains reliable operational stability. This indicates that employing the Sr-deficiency technique with an appropriate level of deficiency is a successful approach to enhance the cathode performance for H–SOFCs. • A Sr-deficiency approach was used to tailor Sr 2-x Fe 1.5 Mo 0.25 Sc 0.25 O 6 (SFMS). • The Sr-deficient SFMS showed improved oxygen and proton diffusion kinetics. • A high fuel cell performance was obtained with the Sr 1.9 Fe 1.5 Mo 0.25 Sc 0.25 O 6 cathode. • Good stability was retained for the Sr 1.9 Fe 1.5 Mo 0.25 Sc 0.25 O 6 cathode. [ABSTRACT FROM AUTHOR]

Efficient electrocatalysts are critical in the advancement of fuel cell technologies and should have superior activity for alcohol oxidation reactions (AORs). Herein, we report a facile one-pot method to synthesize platinum-bismuth nanoalloy (Pt–Bi) on reduced graphene oxide (RGO), enacting the methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) in an acidic solution. The reduction of the Pt and Bi precursors is co-mediated via l -ascorbic acid and ethylene glycol (EG) to afford Pt–Bi nanoparticles with an average size of 5.6 nm highly dispersed on the surface of RGO. Pt–Bi nanoparticle decoration is confirmed by transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX). X-ray photoelectron spectroscopy (XPS) results show the existence of the Pt–Bi metallic phase with minimal oxide. Electrochemical experiments using cyclic voltammetry (CV) reveal that the Pt–Bi/RGO catalyst is considerably more active than commercial Pt/C for AORs. Notably, the mass activity (J mass) of MOR is enhanced by 1.3-fold and EOR is enhanced by 2.3-fold, highlighting the influence of the Pt–Bi interfacial concept. Overall, the results suggest that Pt–Bi/RGO is a highly promising candidate for use in direct alcohol fuel cells. Schematic representation of the Pt–Bi/RGO electrocatalyst for methanol and ethanol direct oxidation reactions. [Display omitted] • Pt–Bi alloy on RGO synthesized successfully by a one-pot method. • Pt–Bi/RGO provides more active sites for methanol and ethanol electro-oxidation. • Bi enhances Pt–Bi nanoparticle CO tolerance for alcohol oxidation. • Pt–Bi/RGO shows mass activity of 0.458 and 0.384 mA μg⁻1-Pt for MOR and EOR. • Improved catalyst stability and activity due to Pt–Bi synergy on RGO support. [ABSTRACT FROM AUTHOR]

In this work, a novel cold startup strategy is presented for a large-scale metal hydride–fuel cell system. Due to the thermal requirement of the system, when the initial temperature of metal hydride and ambient air is low, the system cannot be started because the hydrogen pressure in the metal hydrides storage system is lower than the minimal pressure required by the fuel cell. The cold startup is achieved by maintaining a part of metal hydride storage at a target temperature and using coolant control to transfer heat to the remaining cold metal hydride storage upon operation of the fuel cells. The strategy is studied numerically and a novel Quasi-2-Dimensional approach is developed to describe heat transfer within metal hydrides and validated. By the proper selection of the value of the control variable, both fast startup and immediate uninterrupted fuel cell power supply are achieved. The effect of initial conditions on the startup process is studied and the strategy consumed 30 % less energy than the alternative without control. The proposed strategy is suitable and efficient for the cold startup of large-scale metal hydride-fuel cell systems. • A novel cold startup strategy is proposed for a large scale metal hydride hydrogen storage unit coupled with a fuel cell. • A Quasi 2-D heat and mass transfer model for the metal hydrides storage system is presented and validated. • A successful fast cold startup along with maximum fuel cell power output is achieved using the current strategy. • Energy savings of 30% are achieved for current strategy when compared with an alternative without control. [ABSTRACT FROM AUTHOR]

Fuel cell electric vehicles (FCEVs) hold great promise for achieving sustainable and environmentally friendly transportation. However, their widespread adoption depends on the efficient development of the hydrogen supply chain (HSC) required for refueling these vehicles. Given the interdependence between the HSC and power distribution networks (PDNs), this paper presents an innovative model to jointly plan the HSC and reinforce PDNs. In this new model, the inherent uncertainties related to wind energy generation, load demand, and FCEV consumption are modeled. Furthermore, coordinating the planning of hydrogen storage and battery energy storage systems is incorporated. The results underscore the critical importance of simultaneous planning for the HSC and PDN reinforcement. Moreover, the findings reveal that hydrogen storage alone can provide sufficient energy arbitrage, leading to a 9.6% reduction in total costs compared to the scenario where storage is disregarded. [Display omitted] • A novel planning model for hydrogen supply chains and power distribution networks. • Both hydrogen storage and battery energy storage are included. • Uncertainties related to wind generation and loads are modeled. • Model results show that simultaneous planning cuts costs by 25.9%. • Hydrogen storage alone reduces costs by 9.6%. [ABSTRACT FROM AUTHOR]

The application of hydrogen energy is affected by the safety of hydrogen storage system. To grasp the current status of research and application in the research field of hydrogen storage safety and explore its research development trend, data analysis techniques, such as co-occurrence, co-citation, and burst detection, were adopted to conduct bibliometric analysis of the relevant literature. The study results show that the research hotspots of hydrogen storage safety mainly concentrate on six aspects: the stability of metal hydride hydrogen storage materials, the study of thermal management and stress relief in metal hydride reactors, the safety analysis of hydrogen fuel cells and hydrogen leakage monitoring, the analysis of leakage and explosion risks in hydrogen refueling stations, the study of filling pressure and temperature distribution in hydrogen storage tanks, and the study of safety issues in underground hydrogen storage. Mg-based hydride stability and underground hydrogen storage risk analyses are current research frontiers in hydrogen storage safety. • This paper presents the development of hydrogen storage in safety research. • 1552 papers are visualized and analyzed using bibliometrics. • Identifying research frontiers by combining timeline view with burst detection. • Knowledge bases, research hotspots, and frontiers are discussed. • The current challenges and perspectives for the future are proposed. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive optimization approach for a fuzzy logic-based energy management system (EMS) designed for a fuel cell hybrid electric vehicle (FCHEV) powered by a fuel cell and a battery. The aim is to enhance EMS performance and overall system efficiency by optimizing fuzzy logic parameters using a genetic algorithm (GA). The effectiveness of the proposed strategy is demonstrated through simulations using ADVISOR software and the MATLAB/SIMULINK environment. The optimization process consists of four phases: tuning the membership function types, fuzzy variable ranges, membership function parameters, and rule weights. The proposed method has resulted in a significant improvement in the fitness function, highlighting the high sensitivity of the fuzzy logic system to optimization parameters. The optimized EMS is compared with the original one and a thermostat-based strategy built into ADVISOR. Results show a 28.5% improvement in fuel utilization and a 13% reduction in the low-efficiency operation of the fuel cell system. [Display omitted] • A comprehensive optimization approach for energy management system in FCHEVs. • Simulation environment development with real-time FCHEVs interactive monitoring. • FCHEVs Performances improvement in terms of energy efficiency and management. • FCHEVs Energy losses minimization with robust and efficient decision-making. • Innovative solutions provided to overcome the operating constraints of FCHEVs. [ABSTRACT FROM AUTHOR]

Polybenzimidazole (PBI) doped with phosphoric acid (PA) exhibits fast proton conduction in the range of 120–180 °C. However, PA loss during high temperature fuel cells (HT-PEMFCs) operation and plasticization after PA doping are the main obstacles to PBI membrane application. In this work, the properties of PA-doped PBI membranes were improved by branching polyurethane side chains onto the PBI backbone via N-substitution reaction. The urea and amide-ester bonds between the polyurethane side chains form a rich hydrogen bonding network. The hydrogen bonding network together with Ce–O coordination bonding enhance the mechanical properties of PBI membranes. Long branched chains increase the spacing between the molecular chains, and the additional unbonded groups in the polyurethane side chains can also form hydrogen bonding interactions with the PA, which increase the adsorption and retention capacity of the PA. The proton conductivity of polyurethane grafting PBI reached 0.104 S cm −1, while the conductivity of the pristine PBI membrane was only 0.026 S cm −1 under the same conditions. The PBI membrane grafted with polyurethane side chains showed a proton conductivity of up to 0.104 S cm −1 at 160 °C in anhydrous conditions, whereas the pristine PBI membrane showed a conductivity of only 0.026 S cm −1 under the same conditions. During single-cell testing, polyurethane-grafted PBI membrane peak power densities of 408 mW cm −2 could be achieved. In addition, the polyurethane grafted membrane has excellent durability with a voltage decay of only 245 μV h −1 in a 120 h test. Formation of a rich hydrogen bonding network in the polybenzimidazole membrane after grafting polyurethanes promotes rapid proton transfer. [Display omitted] • Rich hydrogen bonding network. • Ce-O coordination bonds enhance the mechanical properties of membranes. • Excellent durability. [ABSTRACT FROM AUTHOR]

Polymer electrolyte membrane fuel cells (PEMFCs) are an important enabler of the nascent hydrogen economy. However, due to the reliance on precious metal catalysts like platinum, reducing the cost and broad penetration of PEMFCs beyond vehicle application remains a challenge. In this respect, alternative non‐precious metal catalysts and other carbon‐based catalysts remain the holy grail toward advanced low‐cost PEMFC. This review summarizes recent progress along the development of non‐precious catalysts and their performance under PEMFC operation. Critical factors such as the activity, stability, and durability of non‐precious metal catalysts and their associated mechanisms including the paths leading to degradation are discussed. Ultimately, the review concludes by highlighting the impressive activity and potential of NPM catalysts and the areas of focus to enable the translation of non‐precious catalysts to commercially viable PEMFC systems. [ABSTRACT FROM AUTHOR]

In this work, we developed a direct strategy to fabricate Palladene (i. e. Palladium metallene) aerogels and propose a temperature‐dependent growth mechanism. Besides the typical three‐dimensional networks and wrinkled surface morphologies, the as‐prepared Palladene50 ${{Palladene}_{50}}$ aerogel is endowed with abundant Pd2+. The as‐prepared Palladene50 ${{Palladene}_{50}}$ aerogel exhibits an excellent mass activity in the formic acid oxidation reaction and a good half‐wave potential in the oxygen reduction reaction in comparison with Pd/C and a Pd aerogel. This work expands the range of metal aerogels from the perspective of the building block units and demonstrates a direct approach to fabricate highly promising bifunctional electrocatalysts for fuel cells. [ABSTRACT FROM AUTHOR]

The Biomedical Imaging and Therapy facility of the Canadian Light Source comprises two beamlines, which together cover a wide X‐ray energy range from 13 keV up to 140 keV. The beamlines were designed with a focus on synchrotron applications in preclinical imaging and veterinary science as well as microbeam radiation therapy. While these remain a major part of the activities of both beamlines, a number of recent upgrades have enhanced the versatility and performance of the beamlines, particularly for high‐resolution microtomography experiments. As a result, the user community has been quickly expanding to include researchers in advanced materials, batteries, fuel cells, agriculture, and environmental studies. This article summarizes the beam properties, describes the endstations together with the detector pool, and presents several application cases of the various X‐ray imaging techniques available to users. [ABSTRACT FROM AUTHOR]

For the past three decades, research interest in electrospinning (ES) has grown exponentially. Twenty years ago, the initial reports on the utilization of this rather simple ultrafine fiber-forming method in combination with a widely established materials chemistry tool known as sol–gel (SG) and without the aid of electrospun organic fibers as templates (or fiber-forming sacrificial polymers) were published in the open literature. In parallel, several groups right around the same time also proposed the use of long-chain organic polymers in SG formulations to facilitate their spinnability into ultrafine fibers. Since then, the number of research articles exploring SG-ES to produce inorganic fibers with submicron diameters has also grown steadily, resulting in several identifiable R&D sub-fields. Relatively recent advances in ES scalability have now made it even more attractive for exploring potential commercial applications. This review is an attempt to provide readers with a comprehensive overview of SG-ES work done in the areas of metal oxide catalysis, photocatalysis, and adsorption. It does not focus on devices having a catalytic function, such as fuel cells and sensors, but on materials whose end goal is to be used as catalysts or sorbents. A number of potentially valuable opportunities and recommendations are also offered. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR), occurred at cathodes in fuel cells, eco-friendly energy-conversion system, requires efficient electrocatalysts to overcome sluggish reaction kinetics. In this work, to enhance the ORR performance by decreasing potentials, we developed carbonized zeolite-imidazolate frameworks (ZIF) containing Co atoms (Co–C). The final product is produced by two-step process including (i) the formation of ZIF with Co species, and (ii) carbonization of the ZIF using high temperature treatment. Morphological characterizations revealed that the Co–C has polygon-shaped ZIF-based materials with metallic Co particles wrapped by layered carbon structures. The amount of Co atoms is found to be ~ 4 wt%, possessing a large surface area of 718 m2/g. X-ray photoelectron spectroscopy measurements further supported the formation of sp2 carbon structures with N-doping. The Co–C products exhibit an efficient electrocatalytic ORR performance in alkaline media, with their onset and half-wave potentials as of 0.97 and 0.86 V, comparable to those of Pt/C. Furthermore, Co–C shows the excellent cyclic durability and stability against for methanol poisoning. Collectively, this system including Co-based active species on ZIF networks provides a promise route for the development of efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

This work reports a novel TiO2/g-C3N4 photoanode-based photocatalytic fuel cell (PFC) designed to convert chemical energy from simulated wastewater. The g-C3N4 modified TiO2 nanorod was successfully synthesized by a facile hydrothermal method. The results indicated that the maximum photocurrent density reached 2.44 mA cm-2 at 1.23 V vs. RHE by 1.167 g L-1 g-C3N4 loaded TiO2 composite. On the basis of analysis, the photoelectrochemical mechanism of the composite photoanode was proposed. This mainly demonstrated that the composite photoanode increases the electron donor density and boosts charge separation efficiency. In addition, the power density and hydrogen production of the proposed PFC were enhanced by 5.37 and 1.49 times compared to TiO2 photoanode-based PFC. To find the origins of the excellent performance of PFC, the influence of the organic compounds were investigated. The ESR measurement results indicated that the organic matter was captured by the photoexcited holes directly to facilitate the charge separation. The achieved power density and hydrogen production of 0.14 mW cm-2 and 21.60 μmol h-1 cm-2 were measured using RhB as the model pollutant, which was 2.42 and 1.23 times higher than the experiments with PBS electrolyte. This study proposed a novel PFC system converts the organic pollutant to the hydrogen and the electricity. [ABSTRACT FROM AUTHOR]

The article presents a lesson plan for a mindful and engaging introduction to three-dimensional (3D) printing for secondary students.

Hydrogen zirconium phosphate (HZP) is a ceramic material with the formula HZr 2 (PO 4) 3 that can potentially offer anhydrous protonic conductivity, with thermostability for the intrinsic protons up to 650 °C, and good chemical stability in aqueous environments or acid gases. Despite the attraction of these features for electrolyte applications, such as gas separation, fuel cells or electrolysers, work on this material remains in its infancy. A possible reason for this lack of attention may be related to the complexity to obtain the HZP material as a pure phase. For this reason, the current article examines a new hydrothermal synthesis method to produce the ammonium precursor, NH 4 Zr 2 (PO 4) 3 , in its phase pure form, and consequently a refined overall route to produce the desired HZP target material. In the synthesis of the ammonium precursor, we underscore the precise control of reaction conditions that are necessary to obtain the pure NH 4 Zr 2 (PO 4) 3 material, both in its cubic and hexagonal structural polymorphs. For reaction times of 10 h, the cubic phase is obtained by employing a hydrothermal temperature of 150 °C and an aqueous ammonia volume of 2.1 mL, while the hexagonal phase is obtained for a hydrothermal temperature of 200 °C and an aqueous ammonia volume between 2.3 and 2.4 mL. Subsequently, we investigate the required conditions to convert hexagonal NH 4 Zr 2 (PO 4) 3 fully to hexagonal HZr 2 (PO 4) 3 via thermal treatment at 600 °C for 5 h, assessed by a combination of X-ray diffraction and infrared spectroscopy. In this way this article aims to open up further research on this interesting HZP material by documenting a robust route for its preparation. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs), as important energy equipment, have excellent characteristics, including low pollution and high catalytic activity. The cathode, which is the key component of an SOFC, plays a vital role in practical applications. Herein, we study the properties of Ln 0.125 Sr 0.875 Co 0.875 Ta 0.125 O 3-δ (Ln = La, Sm, and Nd, abbreviated as LSCT, SSCT, and NSCT, respectively) cathode materials both theoretically and experimentally. The conductivity of LnSCT gradually decreased with decreasing Ln3+ ionic radius. Density of states (DOS) analysis indicated that LSCT has the highest conductivity owing to the band center of Co 3d being closer to O 1s. Density functional theory (DFT) calculations showed that the SSCT sample has the lowest oxygen vacancy formation energy, which facilitated the formation of oxygen vacancies. The binding energy results show that SSCT and NSCT have relatively good structural stability compared to LSCT. The polarization impedance values of LSCT, SSCT, and NSCT at 700 °C are 0.105, 0.069, and 0.304 Ω cm2, respectively. The CO 2 sensitivity of LSCT, SSCT, and NSCT was evaluated by calculating the CO 2 adsorption energy and performing impedance tests under different CO 2 concentrations. These results indicate that LSCT and SSCT have better CO 2 tolerance than NSCT. At 700 °C, for Ln = La, Sm, and Nd, the maximum power of NiCu-SDC/SDC/LSGM/LnSCT electrolyte-supported fuel cell reached 430, 462, and 382 mW cm−2, respectively. These findings provide a reference for the future design and development of SOFCs cathode material. [ABSTRACT FROM AUTHOR]

In order to maintain the battery SOC, the fuel cell power will fluctuate dramatically, as well as frequent start-stop, which will greatly increase the life attenuation of the fuel cell and reduce the durability. An optimization-based energy management strategy with a real-time model predictive control and pontryagin's maximum principle for FCHEV is proposed in this paper, both the fuel economy and the fuel cell durability are considered in the optimization. A novel model predictive control is studied to achieve energy distribution. After the calculation of predicted speed sequence through back propagation neural network, pontryagin's maximum principle is introduced to solve the optimal control problem in each prediction horizon and obtain the ideal control strategy. In addition, the fuel cell degradation model is introduced in the modeling process, the minimum power point of the fuel cell system is designed to improve the fuel economy and durability of the fuel cell. Compared with the rule-based strategy, the proposed MPC strategy has better performance to reduce the total equivalent hydrogen consumption, which can save up to 8.44% in the test case of the mid-size fuel cell passenger car while maintaining the stability of the battery's state of charge. [ABSTRACT FROM AUTHOR]

In this paper, a Multi-Criteria Decision Analysis methodological framework is developed to rank alternative fuel buses. It is applied to the case-study of the public transportation system of the island of Gotland in Sweden. Seven alternative fuel buses are identified: bioethanol, biodiesel, biogas, plug-in hybrid electric biodiesel, plug-in hybrid electric biogas, battery electric and hybrid electric hydrogen fuel cell buses. These alternatives are evaluated under 11 criteria that are categorized under four dimensions and measured under a Life Cycle Sustainability Analysis approach where possible. The ranking is accomplished by means of the weighted summation method; weights are determined through the Analytic Hierarchy Process. Explicit weights on these criteria provided by local experts and stakeholders are used to evaluate the alternatives under various island-specific scenarios. Results show that biogas and plug-in hybrid electric biogas buses are the preferred alternatives as long as biogas is produced from waste residuals; otherwise, the import of biodiesel could be the preferred short-term alternative. Bioethanol appears to be the least suitable fuel. The developed methodological framework proved helpful to the local authorities of Gotland when they sought to identify the best compromise fuel bus solution and has shown that it can be applied in similar case-studies. [ABSTRACT FROM AUTHOR]

In a unified regenerative fuel cell (URFC) or reversible fuel cell, the oxygen bifunctional catalyst must switch reversibly between the oxygen reduction reaction (ORR), fuel cell mode, and the oxygen evolution reaction (OER), electrolyzer mode. However, it is often unclear what effect alternating between ORR and OER has on the electrochemical behavior and physiochemical properties of the catalyst. Herein, operando X‐ray absorption spectroscopy (XAS) is utilized to monitor the continuous and dynamic evolution of the Co, Mn, and Fe oxidation states of perovskite catalysts Ba0.5Sr0.5Co0.8Fe0.2O3‐δ (BSCF) and La0.4Sr0.6MnO3‐δ (LSM), while the potential is oscillated between reducing and oxidizing potentials with cyclic voltammetry. The results reveal the importance of investigating bifunctional catalysts by alternating between fuel cell and electrolyzer operation and highlight the limitations and challenges of bifunctional catalysts. It is shown that the requirements for ORR and OER performance are divergent and that the oxidative potentials of OER are detrimental to ORR activity. These findings are used to give guidelines for future bifunctional catalyst design. Additionally, it is demonstrated how sunlight can be used to reactivate the ORR activity of LSM after rigorous cycling. [ABSTRACT FROM AUTHOR]

Anion exchange membrane fuel cell (AEMFC) technology is attracting intensive attention, due to its great potential by using non‐precious‐metal catalysts (NPMCs) in the cathode and cheap bipolar plate materials in alkaline media. However, in such case, the kinetics of hydrogen oxidation reaction (HOR) in the anode is two orders of magnitude sluggish than that of acidic electrolytes, which is recognized as the grand challenge in this field. Herein, we report the rationally designed Ni nanoparticles encapsulated by N‐doped graphene layers (Ni@NG) using a facile pyrolysis strategy. Based on the density functional theory calculations and electrochemical performance analysis, it is witnessed that the rich Pyridinic‐N within the graphene shell optimizes the binding energy of the intermediates, thus enabling the fundamentally enhanced activity for HOR with robust stability. As a proof of concept, the resultant Ni@NG sample as the anode with a low loading (1.8 mg cm−2) in AEMFCs delivers a high peak power density of 500 mW cm−2, outperforming all of those of NPMC‐based analogs ever reported. [ABSTRACT FROM AUTHOR]

Carbon-supported platinum-lanthanum (Pt-Ln) intermetallic compound (IMC) nanoparticles with high activity and robust stability have been demonstrated as promising cathode catalysts for proton-exchange membrane fuel cells. However, the preparation of Pt-Ln IMC catalysts needs high-temperature annealing treatment that inevitably causes nanoparticle sintering, resulting in significant reduction of the electrochemical surface area and mass-based activity. Here, we prepare small-sized M-doped Pt5Ce (M = Ga, Cd, and Sb) IMCs catalysts via a low-melting-point metal doping strategy. We speculate that the doping of low-melting-point metals can facilitate the generation of vacancies in the crystal lattice through thermal activation and thus reduce the kinetic barriers for the formation of intermetallic Pt5Ce catalysts. The prepared Ga-doped Pt5Ce catalyst exhibits a higher electrochemical active surface area (81 m2·gPt−1) and a larger mass activity (0.45 A·mgPt−1 at 0.9 V) over the undoped Pt5Ce and commercial Pt/C catalysts. In the membrane electrode assembly test, the Ga-doped Pt5Ce cathode delivers a power density of 0.98 W·cm−2 at 0.67 V, along with a voltage loss of only 27 mV at 0.8 A·cm−2 at the end of accelerated stability test. [ABSTRACT FROM AUTHOR]

Optimization of Pt atom utilization efficiency is critical for the development of proton-exchange-membrane fuel cells. Here we aim to develop an efficient oxygen reduction reaction (ORR) catalyst with a low Pt content through the concurrent modification of Pt-Co alloy catalysts and carbon substrate. In the present study, ultrafine Pt-Co alloy nanoparticles are successfully synthesized and stabilized by topological carbon defects via adopting the ammonia thermal treatment. Despite the low Pt loading, the obtained catalyst exhibits an impressive half-wave potential of 0.926 V versus the reversible hydrogen electrode in 0.1 M HClO4 electrolyte. Furthermore, the durability testing using the timed-current method demonstrates a tiny loss of only 3.6% after 12 h. Both experimental results and theoretical calculations demonstrate that topological carbon defects significantly enhance the charge transfer processes at the alloy/carbon interface, contributing to the strong electronic metal-support interactions between the Pt-Co alloy nanoparticles and topological carbon defects. These interactions, along with the alloy effect, play a crucial role in promoting the ORR performance in acidic media. [ABSTRACT FROM AUTHOR]

The Artificial Neural Network (ANN) is a high-precision modelling technique applied across various applications, but their use in modelling the proton exchange membrane fuel cell (PEMFC) at the stack scale remains limited. This study aimed to enhance the modelling of a 1.2 kWp PEMFC stack using ANN integrated with the LabVIEW program, and to evaluate its accuracy compared to Multiple Linear Regression (MLR) and Analytical Mathematical Model (AMM) methods based on experimental data. The ANN model was tested on the polarization curve under pressures ranging from 1 to 9 bar and currents from 1 to 40 A. Accuracy was assessed using analysis of variance (ANOVA) with a significance level of p = 0.05, focusing on key statistical performance metrics. The results indicate that the ANN model significantly enhances PEMFC stack modelling accuracy, especially for activation and concentration loss processes. The ANN demonstrates a substantial improvement, reducing error metrics by at least 28% compared to MLR and 75% compared to AMM. [ABSTRACT FROM AUTHOR]

Polyimides are used in various applications, including fuel cells, membranes, and microelectronics, due to their outstanding tensile properties, great thermal stability, low dielectric constant, and chemical inertness. Applications requiring even lower dielectric constants include interlayer dielectrics and tape‐automated bonding. In this study, a covalent organic framework (COF‐1) was synthesized and dispersed in various percentages into a solution of terpoly(amide acid) (TPAA) to produce COF‐1/terpolyimide composites. 3,3′,4,4′‐Oxydiphthalic dianhydride (ODPA), 3,3′,4,4′‐biphenyltetracarboxylicdianhydride (BPDA), and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) were reacted with 4,4′‐(hexafluoroisopropylidene)bis[(4‐aminophenoxy)benzene] (HFBAPP) or 4,4′‐(hexafluoroisopropylidene) dianiline (6FpDA) to form terpoly(amide acid). In this case, monomers with fluorinated substituents (HFBAPP, 6FpDA, and 6FDA) were utilized to improve free volume. Pores of COF‐1 and gaps between polyimide chains and COF‐1 can be filled with air with a dielectric constant (κ) ~1, lowering the κ value of terpolyimide composites. The κ value of COF‐1/terpolyimide composites decreased as COF‐1 content increased, reaching a minimum of 1.96. Tensile properties decreased slightly with increasing COF‐1 levels. The terpolyimides and their composites were thermally stable up to approximately 520°C. As a result, these polymer composites look promising for use as insulators in microelectronic applications. Highlights: Terpolyimide is prepared using fluorinated monomers to improve bulk volume.Incorporated COF‐1 into terpoly(amide acid) to introduce pores/voids and reduce dielectric constant.Developed COF‐1/terpolyimide composites with a low dielectric constant of 1.96.Optimized COF‐1/terpolyimide composites for microelectronic applications. [ABSTRACT FROM AUTHOR]

The article presents new propulsion concepts and related new energy sources of modern means of transportation. One of them is hydrogen fuel cells, widely regarded as one of the most promising and alternative solutions due mainly to their ecological nature. Also presented, the biggest problem associated with the development of fuel cells which is hydrogen. A huge energy input is used to produce it. In addition, the storage of hydrogen is highly problematic. With the introduction of increasingly stringent changes regarding toxic emissions into the atmosphere and the move toward emission-free transportation, the article examines the possibilities of converting a ship's reciprocating internal combustion engine propulsion system into an environmentally friendly one. In the rest of the article, legal aspects affecting the reduction of the environmental impact of exhaust emissions in the maritime industry are presented. Examples of fuel cell applications in current means of transportation are also discussed. In the main part of the article, the ship to be converted is presented, along with the planned voyage route. The main engine was converted to alternative electric motors, and a reduction gearbox in the main propulsion system was also selected. The power requirements for converting the ship's propulsion system were then determined. An inverter was selected to convert the generated direct current to alternating current and batteries to store the generated electricity. The final part of the article will analyse the feasibility of converting the propulsion of a Panamax-type bulk carrier with a piston internal combustion engine into an environmentally friendly propulsion system using a hydrogen fuel cell. The analysis will be carried out in terms of cost-effectiveness and technical feasibility. The article ended with conclusions. [ABSTRACT FROM AUTHOR]

To overcome the flow deficit in high pumping flow applications, a parametric study is presented involving three Multiple Micropump system (MMS) configurations: Series Multiple Micropump System (SMMS), Parallel Multiple Micropump System (PMMS) and hybrid Series-Parallel Multiple Micropump System (SPMMS). The performance of the MMS configurations was investigated using analytical and experimental approach. The MMS operating at 'in-phase' mode (0° phase difference) was observed to exhibit flow pulsations. Therefore, the MMS was operated at 'out-of-phase' mode (90° phase difference) to minimise the flow pulsations. The maximum flow rate at the 'in-phase' mode was observed to be 37.58 ml/min, 112.32 ml/min and 51.81 ml/min for SMMS, PMMS and SPMMS configurations respectively. Whereas the flow pulsation results indicate that the degree of flow pulsation for SMMS, PMMS and SPMMS configurations was decreased by 13.4%, 13.5% and 13.3% respectively when operated at 'out-of-phase' mode. The maximum back pressure of 140 kPa, 40 kPa and 100 kPa was recorded for SMMS, PMMS and SPMMS configurations respectively. It was found that the flow rate and backpressure vary significantly with the actuation frequency and series-parallel modes for MMS. The proposed series-parallel MMS configurations can be used in biomedical, thermal management and fuel cell applications. [ABSTRACT FROM AUTHOR]

The power quality (PQ) variations due to the introduction of electric vehicles (EVs) and Electric Vehicle Charging Stations (EVCS) into the power system network is the foremost limitation which is holding back the push for a complete overhaul of fossil fuel-based internal combustion (IC) engine vehicles by EVs. With the emergence of EVs into the mainstream in the automobile sector, this research article proposes a system wherein distributed energy resources (DERs) like Fuel-Cells (FCs) are integrated to grid in order to supply for the additional power demand created by the EVs such that the current injected from FC compensates the grid current harmonics maintain the grid current THD ≤ 5% as per IEEE519 standards. A Particle Swarm Optimized (PSO) based PI current controller and a Fuzzy-logic-based controller are proposed for a grid connected fuel cell so as to mitigate the grid current deterioration caused due to the presence of existing nonlinear loads as well as EVCS. In addition, the parameters like grid voltage distortion and frequency variance are considered simultaneously to ascertain the capability of proposed controllers. This work is carried out in the MATLAB/SIMULINK environment. [ABSTRACT FROM AUTHOR]

Proton‐exchange membrane fuel cells (PEMFCs) and water electrolysis (PEMWE) are rapidly developing hydrogen energy conversion devices. Catalyst layers and membranes have been studied extensively and reviewed. However, few studies have compared gas diffusion layers (GDLs) in PEMWE and PEMFC. This review compares the differences and similarities between the GDLs of PEMWE and PEMFC in terms of their material and mass transport characteristics. First, the GDL materials are selected based on their working conditions. Carbon materials are prone to rapid corrosion because of the high anode potential of PEMWEs. Consequently, metal materials have emerged as the primary choice for GDLs. Second, the mutual counter‐reactions of the two devices result in differences in mass transport limitations. In particular, water flooding and the effects of bubbles are major drawbacks of PEMFCs and PEMWE, respectively; well‐designed structures can solve these problems. Imaging techniques and simulations can provide a better understanding of the effects of materials and structures on mass transfer. Finally, it is anticipated that this review will assist research on GDLs of PEMWE and PEMFC. [ABSTRACT FROM AUTHOR]

The performance of ammonia hydrogen fuel cells (AHFCs) with the same activated area but different aspect ratio is quite different. In this paper, based on the diffusion characteristics of hydrogen nitrogen mixture, five different aspect ratios of AHFCs were designed, and the influence of aspect ratio on the performance of AHFCs was studied by combining experiment and simulation analysis. The results reveal that the power of AHFCs reaches the maximum when the aspect ratio is 1, that is, the shortest hypotenuse of the plate. With the extension of the hypotenuse, the output power decreases, and the output power decreases by 19.3% when the aspect ratio is 4. Due to the strong ability of hydrogen diffusion, when the aspect ratio of AHFCs is 4, the proportion of hydrogen and oxygen starvation area at the interface reaches the maximum and minimum, which are 11.8% and 0.3% respectively, which is contrary to the aspect ratio of 0.25. A larger aspect ratio is conducive to the uniform distribution of gas-water-heat. Although the AHFCs with aspect ratio of 0.64 has advantages in power generation efficiency and fuel utilization, the pressure drop loss increases by 43.7%, and the pressure drop loss with aspect ratio of 0.25 increases by 141.2%. • Experimental data of AHFCs with different aspect ratios are obtained. • Power generation efficiency of AHFCs with different aspect ratios is compared. • AHFC with the shortest hypotenuse has the largest output power. • CV is used to characterize the uniformity of gas-heat-water distribution in AHFC. [ABSTRACT FROM AUTHOR]

This study assesses the integration of hydrogen fuel cell vehicles (FCVs) with battery electric vehicles (BEVs) to support Taiwan's 2050 net-zero emissions goal. Using life cycle assessments and vehicle fleet modeling, we analyze hydrogen production pathways and forecast greenhouse gas (GHG) emissions across Taiwan's on-road vehicle fleet. Despite the BEV-FCV integration scenario, we project that the road transport sector could still emit 7.83 million tonnes of GHGs by 2050–145% above the government's target. Significant challenges include inadequate policies for electrifying heavy-duty vehicles, expected to contribute 50.4% of direct emissions in 2050, and the delayed phase-out of inefficient light-duty vehicles. Transitioning heavy-duty vehicles to zero-emission alternatives could reduce emissions by around 3.95 million tonnes. Our findings highlight the essential role of FCVs and robust hydrogen technologies in achieving sustainable transport, emphasizing the need for comprehensive electrification strategies. • Identifies up to 71.2% GHG reduction by 2050 in hydrogen production. • Projects FCVs to lower GHG, comparing ICEVs and BEVs by 2050. • Forecasts HDVs to cause over 50% of on-road transport emissions by 2050. • Urges phasing out old light-duty vehicles to cut legacy emissions. • Advocates quick policy shifts to electrify heavy-duty vehicles. [ABSTRACT FROM AUTHOR]