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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]

If hydrogen fuel is available to support the transportation sector decarbonization, its usage can be placed either directly onboard in a fuel cell vehicle, or indirectly, off-board, by using a fuel cell power station to produce electricity to charge a battery electric vehicle. Therefore, in this work, the direct and indirect conversion scenarios of hydrogen to vehicle propulsion were investigated regarding energy efficiency. Thus, in the first scenario, hydrogen is the fuel for the onboard electricity production to propel a fuel cell vehicle while in the second, hydrogen is the electricity source to charge the battery electric vehicle. When simulated for a drive cycle, results have shown that the scenario with the onboard fuel cell consumed about 20% less hydrogen, demonstrating higher energy efficiency in terms of driving range. However, energy efficiency depends on the outside temperature when heat loss utilization is considered. For outside temperatures of −5 °C or higher, the system composed of the battery electric vehicle fueled with electricity from the off-board fuel cell was shown to be more energy-efficient. For lower temperatures, the system composed of the onboard fuel cell again presented higher total (heat + electricity) efficiency. Therefore, the results provide valuable insights into how hydrogen fuel can be used for vehicle propulsion, supporting the hydrogen economy development. [Display omitted] • H 2 allocation for vehicle propulsion onboard or off-board is considered. • Electrical/thermal efficiency of the two hydrogen usage scenarios is investigated. • Hydrogen allocated onboard, i.e. in a fuel cell vehicle, consumed less H 2 per km. • Off-board H 2 usage, i.e. to power a battery vehicle, had high electrical/thermal efficiency. [ABSTRACT FROM AUTHOR]

Proton electrolyte membrane fuel cells are gaining relevance in different energy sectors as a viable alternative to the use of fossil fuels. Among others, the automotive industry is one of the sectors that has focused a special interest on this technology with the aim of reducing its gas emissions. Thus, with the increase in the production to great scale of proton exchange membrane fuel cells (PEMFC), the amount of catalyst demanded is expected that increase accordingly. In this context, the optimization of both, the composition of the catalyst ink used, and the technique employed for the fabrication of the catalyst layers (CL), are two of the main challenges to be solved in this field. Electrospray is an optimized technique to prepare catalyst layers (CL) for fuel cells. However, aspects such as the voltage applied in the electrospray and the aging of the catalyst inks until its use for the catalyst layer preparation, are some of the key aspects to be studied because they can significantly alter their fuel cell performance. Therefore, this work was focused on studying by cyclic voltammetry, how the voltage used in the electrospray and the ink aging alter the morphology of the catalyst layer and, consequently, their performance in a fuel cell. [Display omitted] • Optimization of the electrospray deposition technique. • The morphology of the catalyst layer is influenced by the voltage applied. • The aging of catalyst ink introduces a critical factor in the catalyst morphology. [ABSTRACT FROM AUTHOR]

The increasing worldwide need for energy, driven by urbanization and industrialization, necessitates the implementation of efficient and sustainable energy solutions. This research presents a novel hybrid energy system that combines wind turbines, Compressed Air Energy Storage (CAES), and Solid Oxide Fuel Cells (SOFC) to substantially decrease dependence on fossil fuels and mitigate greenhouse gas emissions. The planned system for Beijing, China, leverages the area's wind characteristics to attain a net power production of 474 MWh. The system achieves an exergetic round efficiency of 38.2%, ensuring excellent performance and minimal emissions. The levelized cost of electricity is projected at 108 USD/MWh, with an aggregate cost of 51.4 USD/h. Seasonal variations are significant, with March exhibiting the peak power production of 202.6 MWh and the greatest cost of 174.2 USD/MWh, whilst August has the lowest figures, with power at 105.6 MWh and expenses at 111.6 USD/MWh. The seasonal patterns demonstrate the system's capacity to adjust to wind fluctuations while preserving economic viability. The integration of CAES with SOFC guarantees dependable power production during times of low wind, making the suggested system an efficient and sustainable option for long-term energy requirements. • A new hybrid energy system is introduced to improve fuel cells' performance. • The system is driven by a wind farm for higher renewable integration into the grid. • A comprehensive performance assessment is conducted, and the system is optimized. • The system for Beijing is sustainable, affordable, and environmentally friendly. • An exergetic efficiency and power cost of 38% and 108 USD/MWh are achieved. [ABSTRACT FROM AUTHOR]

Recently, direct methanol fuel cells (DMFCs) have been regarded as the greatest energy-producing owing to their low operating temperature, high production rate of methanol, and low greenhouse gas emission. However, the energy conversion efficiency of the DMFCs is still unsatisfactory due to the slow kinetics of the fuel oxidation reaction. So, an economic electrocatalyst with high efficiency and good stability is still needed. Herein, low-cost nanocomposites of (Ni/Cu/N) MOF and palm pollen-derived G-graphite were prepared with different ratios namely, (1:1), (1:2), and (2:1) through a solvothermal reaction. The nanocomposites were characterized via X-ray diffraction (XRD), Scanning electron Microscopy (SEM), Fourier transform infrared (FTIR), Thermal gravimetric analysis (TGA), and, (Brunauer–Emmett–Teller) technique (BET). Electrodes have been tested as electro-catalysts for methanol-oxidation reaction (MOR) in a basic medium. As revealed from the cyclic voltammetry measurements, all electrodes exhibit a good response to MOR, being the nanocomposite with the ratio between (Ni/Cu/N) MOF and G-graphite (2:1) is the best with an oxidation peak current density of 55 mA/cm2 at a scan rate of 50 mV/s, with an onset potential of 0.35 V, and stability reaches 96 %. The electrochemical impedance spectroscopy (EIS) test showed that the ratio (2:1) has the lowest charge transfer resistance, R CT , of 5.21 Ω which confirms its higher electrochemical activity. This superior performance of the (Ni/Cu/N) MOF and G-graphite (2:1) over other reported MOF-based electrocatalysts is attributed to the synergistic effect of the (Ni/Cu/N) MOF electrocatalyst, wherein Ni and Cu provide redox electrocatalytic active sites for MOR while the G-graphite contributes towards the chemical stability and electrical conductivity of the electrode, respectively. The good activity and stability of the prepared electrodes suggest the potential use of these electrodes as electrocatalysts for MOR in direct methanol fuel cells (DMFCs).This study opens the venue for valorizing the natural wastes derived graphitic material as stable supporting material in Mof based composites electrodes for MOR. • Green Graphite derived from palm pollen grains was prepared simply. • low-cost nanocomposites of (Ni/Cu/N) MOF pollen-derived G-graphite were prepared. • (Ni/Cu/N) MOF- based nanocomposites prepared with different ratios. • The prepared materials were tested as electro-catalysts for MOR. • Nanocomposite of (Ni/Cu/N) MOF and G-graphite with a ratio (2:1) display superior performance. [ABSTRACT FROM AUTHOR]

An innovative photocatalytic fuel cell (PFC)-based self-powered system was developed by integrating the perovskite Ag3BiO3/Ti3C2 MXene plasmonic heterojunction with a self-breathing strategy, which was beneficial for developing high-performance self-powered photoelectrochemical biosensors. [ABSTRACT FROM AUTHOR]

The discovery of a cutting-edged electrocatalyst for water-splitting is an immense challenge to developing metal–air batteries and fuel cells. Therefore, developing sophisticated electrocatalysts with high activity and stability based on non-noble metal elements remains a great challenge. Herein, we prepared efficient polyhedral Ni/Cu bimetallic MOFs that are synthesized by a simple solvothermal method, in which the incorporation of Ni enhances the electrocatalytic properties of CuBTC MOF with distinct molar ratios. Benefiting from the unique morphology, and the favourable effect of Ni incorporation, the polyhedral Ni/Cu bimetallic MOFs exhibit conspicuous efficiency towards OER. The optimized NiCuBTC (2 : 8) bimetallic MOF exhibited superior activity with an overpotential of 290 mV to reach the current density of 10 mA cm−2. Moreover, the NiCuBTC (2 : 8) MOF also shows better long-term stability. The present work shows a facile strategy to design and synthesize a NiCuBTC (2 : 8) MOF electrocatalyst, which offers superior electrocatalytic performance towards water electrocatalysis. [ABSTRACT FROM AUTHOR]

Research on the highly conductive solid electrolyte with the overall composition of (La,Sr) (Ga,Mg)O 3-δ (LSGM) has reached a new stage of development in recent years due to the successes in the field of symmetrical electrochemical devices in which LSGM utilizing as a supporting layer. This study shows a "step-by-step" approach to modify the LSGM electrolyte using both individual techniques and their combinations to improve the functional properties of the LSGM. As a result of a multi-step modification, the new electrolyte of composition (La 0.8 Sr 0.2) 0.98 Ga 0.7 Fe 0.1 Mg 0.2 O 3-δ + 0.5 wt% Fe 2 O 3 was obtained. It is shown that the conductivity of new electrolyte is about five times higher than that of the basic La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ oxide at 600 °C. Furthermore, the better thermo-mechanical and chemical compatibility with the iron-based electrode was found. It also shows insignificant resistance degradation in long-term tests in air and satisfactory stability in wet hydrogen. Based on the results of the research it can be concluded that the new electrolyte obtained by step-by-step modification has great prospects for utilization in symmetrical fuel cells. [ABSTRACT FROM AUTHOR]

The novel perovskite Sr 0.90 Ba 0.10 Co 0.95 Ti 0.05 O 3-δ has been designed as cathode material to be used in intermediate-temperature solid oxide fuel cells (IT-SOFC). To enlarge the unit-cell size and enhance oxygen diffusion, Sr atoms have been partially substituted by a 10 % of Ba. This new compound was characterized through X Ray Diffraction (XRD) unveiling a tetragonal phase at RT. An in situ Neutron Powder Diffraction (NPD) study between RT and 800 °C showed a transition to a cubic perovskite at 400 °C, which was also noticeable in the thermogravimetric analysis (TGA) and dilatometric analysis. Adequate chemical and mechanical compatibility were achieved with the components of the cell. Electrical conductivity peaked at 400 °C, with values over 200 S cm−1 , where it changed its behavior from semiconductor-like to insulator. Finally, polarization resistances as low as 0.062 Ω cm−2 were obtained for the working temperature of the cell in a symmetric cell, associated with the excellent power densities of 564 and 752 mW cm−2 obtained at 850 °C using pure H 2 as fuel for the conventional test fuel cell and in a Pd-infiltrated one. [ABSTRACT FROM AUTHOR]

Nafion is a sulfonated tetrafluoroethylene based fluoropolymer that has been widely used as a membrane material for various applications, such as fuel cells, batteries, and sensors. Nafion has some unique properties that make it suitable for biosensing, such as high ionic conductivity, biocompatibility, chemical stability, and perm selectivity. Nafion can also act as an immobilization matrix for enzymes, antibodies, DNA molecules, and other biomolecules, enhancing their stability and activity on the electrode surface. In this review, we summarize the recent advances and applications of nafion based biosensors for the detection of various analytes, such as glucose, lactate, hydrogen peroxide, DNA, urea, and dopamin. We also discuss the incorporation of nanoparticles into nafion based biosensors, as they can form synergistic interactions that can improve the biocompatibility, stability, selectivity, and sensitivity of the biosensor. We highlight the different transduction methods employed by nafion based biosensors, such as electrochemical, electro chemiluminescence, or electrical impedance. Finally, we outline the challenges and opportunities for future research on nafion based biosensors. [ABSTRACT FROM AUTHOR]

This study loaded different amounts of UiO‐66‐NH2 onto sulfonated polyphenylene sulfide fibers (SPPS), successfully loading UiO‐66‐NH2 on SPPS fibers confirmed by energy dispersive x‐ray spectroscopy, x‐ray diffraction, and Fourier transform infrared spectroscopy. The UiO‐66‐NH2‐X@SFM were then impregnated in Nafion solution to obtain UiO‐66‐NH2‐X@SFM/Nafion composite membranes. The thermal stability, dimensional stability, mechanical properties, proton conductivity, methanol resistance, and other properties of the UiO‐66‐NH2‐X@SFM/Nafion composite membranes were subsequently comprehensively characterized. The proton conductivity of the UiO‐66‐NH2‐8@SFM/Nafion composite membrane at 80°C and 100% RH was measured to be 0.286 S cm−1, which exhibited a significant enhancement of 1.75 times compared with the original membrane. Simultaneously, the composite membrane demonstrated a remarkable reduction in methanol permeation rate. At 40°C and 100% RH, the UiO‐66‐NH2‐8@SFM/Nafion composite membrane has a selectivity of up to 20.7 × 104 S s cm−3 and a single cell density of 88.3 m W cm−2 at 60°C and 100% RH. [ABSTRACT FROM AUTHOR]

The utilization of hydrazine in aiding water electrolysis presents a promising avenue for achieving highly efficient hydrogen production through energy conversion. Herein, bifunctional electrocatalyst of urchin‐like iron, nickle‐codoped cobalt phosphide supported on Ni foam (FeNi‐CoP/NF) is reported. Benefitting from the combined electronic structure and lattice strain engineering by Fe and Ni‐ codoping, the hydrazine‐assisted seawater electrolysis assembled with FeNi‐CoP/NF as both electrodes can achieve an industrial‐level current density of 1.5 A cm−2 at a record‐setting voltage of 163 mV at 70 °C and sustain stable operation for hundreds of hours in seawater environment. The existence of a potential coincidence region lends credibility to the feasibility of implementing self‐activated hydrazine‐assisted seawater electrolysis. Based on theoretical calculations, the separate and synergistic effects of electronic structure and lattice strain engineering are investigated and an integrated illustration of these two strategies on enhancing hydrogen evolution and hydrazine oxidation activity is provided. Moreover, an innovative multi‐powered hydrogen generation system featuring a direct hydrazine fuel cell, rechargeable Zn‐hydrazine battery, and hydrazine‐assisted seawater electrolysis is proposed, underscoring the unique advantages of hydrazine oxidation reaction and its prospective contribution to electrochemical energy conversion technologies powered by sustainable sources. [ABSTRACT FROM AUTHOR]

A soft lithographic method is developed for making bipolar membranes (BPMs) with catalytic junctions formed from arrays of vertically oriented microscale cylinders. The membranes are cast from reusable polydimethylsiloxane (PDMS) molds made from silicon masters, which are fabricated on 2″ to 4″ wafer scales by nanosphere lithography. High‐aspect‐ratio junctions are made on a length scale similar to the thickness of optimized catalyst layers for water dissociation, creating a platform for probing the dual effects of catalysis and local electric field at the microscale BPM junction. Optimized polymer materials and nanoscale metal oxide catalysts are used in this study. 3D BPMs are tested under reverse and forward bias conditions, exhibiting superior performance relative to their 2D counterparts. Under forward bias in H2‐O2 fuel cells, 3D BPMs achieve a current density of 1500 mA cm−2, ≈7 times higher than 2D membranes made from the same materials. [ABSTRACT FROM AUTHOR]

Designing efficient and CO‐tolerant catalysts for hydrogen oxidation reaction (HOR) in anode is one of the challenges for alkaline exchange membrane fuel cells in practical application. Herein, Ru‐MnO heterostructure with two adjacent clusters supported on commercial carbon (BP 2000) (denoted as Ru‐MnO/C) is designed to accelerate the sluggish kinetics of alkaline HOR. The cluster–cluster heterostructure interface modifies the electronic structure of Ru sites with electron transfer from Ru to MnO, then optimizes the adsorption of intermediates on Ru sites. Consequently, this catalyst exhibits high catalytic HOR activities in alkaline media with high exchange current density (3.71 mA cm−2) and mass activity (0.78 A mgRu−1). Meanwhile, the alkaline exchange membrane fuel cell delivers a specific peak power density (PPD) of 7.0 W mg−1Ru under H2/O2 condition, which is higher than that of most reported catalysts. More importantly, the catalyst also demonstrates the remarkable stability and CO‐tolerance. This work presents the superiority of cluster–cluster heterostructure interface toward efficient HOR, which is expected to further enlighten the design of advanced catalysts for electrocatalysis. [ABSTRACT FROM AUTHOR]

Overcoming the trade‐off between the graphitization of the carbon substrate and enhanced electronic metal–support interaction (EMSI) and intrinsic activity of Pt‐C catalysts remains a major challenge for ensuring the durable operation of energy conversion devices. This article presents a hybrid catalyst consisting of PtFe nanoparticles and single Pt and Fe atoms supported on N‐doped carbon (PtFeNPs@PtFeSAs‐N‐C), which exhibits improved activities in hydrogen evolution and oxygen reduction reactions (HER and ORR, respectively) and has excellent durability owing to the high graphitization, rich edge defects, and porosity of the carbon in PtFeNPs@PtFeSAs‐N‐C, as well as strong EMSI between the PtFe nanoparticles and edge‐defective carbon embedded with Pt and Fe atoms. According to theoretical calculations, the strong EMSI optimizes the H* adsorption–desorption and facilitates the adsorption OOH*, accelerating the HER and ORR processes. A novel flow seawater‐Al/acid hybrid fuel cell using the PtFeNPs@PtFeSAs‐N‐C cathode can serve as a high‐efficiency energy conversion device that delivers a high power density of 109.5 mW cm−2 while producing H2 at a significantly high rate of 271.6 L m−2 h−1. Moreover, PtFeNPs@PtFeSAs‐N‐C exhibits a remarkable performance (high power density of 298.0 mW cm−2 and long‐term durability of 1000 h) in a flow Zn–air battery. [ABSTRACT FROM AUTHOR]

Various advanced sources have been developed to cope with the exponential need for world energies, such as hydrogen production, photovoltaic solar cells, lithium batteries and fuel cells, etc. Among these, fuel cells are better owing to their power production, renewability, and green natural technology. In fuel cells, chemical energy is converted into electrical energy with the help of an electrochemical device, having three major components, i.e. electrodes, electrolytes and catalysts. Bismuth-based materials would be a good choice to develop an efficient fuel cell and can be used as electrodes, electrolytes, and catalysts. Bi2SiO5@NG(NG = nitrogen-doped graphene) is a Bi-based nano-composite used as a cathodic catalyst to enhance the oxygen reduction reaction (ORR). Co−Bi@rGO (rGO = reduced graphene oxide) is used as an anode for an EtOH fuel cell due to its low cost and high efficiency. Bi-based solid oxide electrolytes, e.g. sulfonated poly(ether, ketone) (SPEEK) polymer having 7.5 wt.% of bismuth cobalt zinc oxide (BCZO) with a high-power density of 574 mW cm−2 have been reported in this regard. These factors accentuate the relevance of bismuth-based materials for the production of components for fuel cells that have excellent performance. This review examines the published literature on bismuth-based materials and anticipates the synthesis, and role of material in fuel cells. Finally, current challenges and future perspectives present comprehensive guidelines for future research. [ABSTRACT FROM AUTHOR]

The synthesis of cone‐shaped Pt nanoparticles featuring compressively‐strained {111} facets by depositing Pt atoms on the vertices of Pd icosahedral nanocrystals, followed by selective removal of the Pd template via wet etching, is reported. By controlling the lateral dimensions down to ca. 3 nm, together with a thickness of ca. 2 nm, the Pt cones show greatly enhanced specific and mass activities toward oxygen reduction, with values being 2.8 and 6.4 times those of commercial Pt/C, respectively. Both the strain field and the observed activity trend are rationalized using density functional theory calculations. With the formation of ultrathin linkers among the Pt cones derived from the same Pd icosahedral seed, the interconnected Pt cones acquire stronger interactions with the carbon support, preventing them from detachment and aggregation during the catalytic reaction. Even after 20 000 cycles of accelerated durability test, the Pt cones still show a mass activity 5.3 times higher than the initial value of the Pt/C. [ABSTRACT FROM AUTHOR]

Efficient, durable, and economical oxygen reduction catalysts are key for practical applications such as fuel cells and metal–air batteries. Single atom catalysts (SACs) have attracted sustained and widespread attention owing to their unique electronic properties and exceptional atomic utilization, positioning them as promising electrocatalysts in energy conversion and storage. However, the symmetric charge distribution of the metal site in the symmetric M‐N4 configuration of SACs is not conducive to electron transfer and transport in electrocatalytic reactions, resulting in a low adsorption energy for oxygen reduction reaction (ORR) related species (*OH, *O, and *OOH), which severely limits the intrinsic activity of the electrocatalysts. To overcome this limitation and improve the activity and durability, heteroatom doping can effectively modulate the local coordination environment (LCE) of the metal atom, including the coordinating atoms, coordination shells and coordination number. These modifications have significantly improved the performance of carbon supported SACs with M‐N4 configuration in the ORR. Based on this, a thorough summary of the major progress made in recent years in adjusting the LCE of SACs through doping with heteroatoms is provided and a perspective on the future development is offered here. [ABSTRACT FROM AUTHOR]

This paper presents the "Three Gorges Hydrogen Boat No. 1", a novel green hydrogen-powered vessel that has been successfully delivered and is currently sailing. This vessel, integrated with a hydrogen production and bunkering station at its dedicated dock, achieves zero-carbon emissions. It stores 240 kg of 35 MPa gaseous hydrogen and has a fuel cell system rated at 500 kW. We analysed the engineering details of the marine hydrogen system, including hydrogen bunkering, storage, supply, fuel cell, and the hybrid power system with lithium-ion batteries. In the first bunkering trial, the vessel was safely refuelled with 200 kg of gaseous hydrogen in 156 min via a bunkering station 13 m above the water surface. The maximum hydrogen pressure and temperature recorded during bunkering were 35.05 MPa and 39.04 °C, respectively, demonstrating safe and reliable shore-to-ship bunkering. For the sea trial, the marine hydrogen system operated successfully during a 3-h voyage, achieving a maximum speed of 28.15 km/h (15.2 knots) at rated propulsion power. The vessel exhibited minimal noise and vibration, and its dynamic response met load change requirements. To prevent rapid load changes to the fuel cells, 68 s were used to reach 483 kW from startup, and 62 s from 480 kW to zero. The successful bunkering and operation of this hydrogen-powered vessel demonstrates the feasibility of zero-carbon emission maritime transport. However, four lessons were identified concerning bunkering speed, hydrogen cylinder leakage, hydrogen pressure regulator malfunctions, and fuel cell room space. The novelty of this work lies in the practical demonstration of a fully operational, hydrogen-powered maritime vessel achieving zero emissions, encompassing its design, building, operation, and lessons learned. These parameters and findings can be used as a baseline for further engineering research. [Display omitted] • Configuration of a zero-carbon emission vessel using green hydrogen fuel. • Engineering details of a 500 kW marine hydrogen and PEMFC system. • Hydrogen bunkering process, pressure, and temperature management. • Performance of a hydrogen-powered vessel during sailing. • Lessons learned from the design and construction of a marine hydrogen system. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the feasibility of combining direct glucose alkaline fuel cell (DGAFC) with microbial fuel cell (MFC) process. The system of two DGAFC cells combined with an MFC cell was successfully operated for the first time with 1 g/L glucose in 50 mM carbonate buffer solution at a pH of 10.5. The combined system achieved 99% of Coulombic efficiency and produced 6.68 and 1.80 times the total Coulombs of two DGAFC cells and one MFC cell, respectively. No accumulation of gluconic acid and high glucose mineralization were detected in the combined system within 72 h. High performance of the combined system was attributed to the synergistic effect between glucose conversion to gluconic acid in the DGAFC and its utilization by electrochemically active bacteria and fermenters in the MFC. Our results could be useful for developing novel glucose fuel cell. [Display omitted] • DGAFC combined MFC process was successfully operated for the first time. • 99% of CE and efficient glucose mineralization were obtained. • The combined system harvested much higher Coulombs that DGAFC and MFC alone. • The synergistic effect between DGAFC and MFC was discussed. [ABSTRACT FROM AUTHOR]

Improving social acceptance of hydrogen refueling stations (HRSs) involves prioritizing several key factors. Specifically, developing a robust infrastructure of HRSs is critical for implementing hydrogen fuel cell electric vehicles (FCEVs). However, the expansion of HRSs is primarily restricted by the social acceptance of hydrogen-based technologies. Therefore, here, we assessed the perceptions of policymakers regarding the social acceptance of HRSs in Japan and South Korea, where policymakers recognize the vitality of acceptance among residents for advancing FCEV adoption and the importance of market acceptance and sociopolitical acceptance. Japanese experts contend that corporate-level financial feasibility is crucial for achieving social acceptance, whereas South Korean experts prioritize benefit sharing for gaining individual-level acceptance. These insights highlight both common and differentiated factors related to the social acceptance of FCEVs, thereby informing policies on alternative fuel sources to facilitate the broader adoption of HRSs not only in Japan and Korea but also worldwide. • Hydrogen refueling stations are required to reduce dependence on fossil fuels. • Social acceptance is key to promoting the use of fuel cell electric vehicles (FCEV). • Market factors and socio-political acceptance also promote FCEV adoption. • Corporate financial feasibility and individual acceptance are also key factors. • These insights can aid FCEV policymaking in Japan and South Korea. [ABSTRACT FROM AUTHOR]

This paper examines the electrification of transportation as a response to environmental challenges caused by fossil fuels, exploring the potential of battery electric vehicles and hydrogen fuel cell vehicles as alternative solutions. However, a significant barrier to their widespread adoption is the limited availability of charging infrastructure. Therefore, this study proposes the development of comprehensive charging stations capable of accommodating both battery and hydrogen vehicles to address this challenge. The energy is purchased from the day-ahead and intraday auction-based electricity markets, where the electricity price is subject to uncertainty. Therefore, a two-stage stochastic programming model is formulated while the price scenarios are generated utilizing a k-means clustering algorithm. Given the complexity of the proposed model, an efficient solution approach is developed through the hybridization of the Benders decomposition algorithm and stochastic dual dynamic programming. In the Benders master problem, day-ahead bidding variables are determined, whereas the Benders sub-problem addresses intraday bidding and charging station scheduling variables, employing stochastic dual dynamic programming to tackle its intractability. Additionally, we transform the mixed integer linear program model of the second stage problem into a linear program, confirming its validity through KKT conditions. Our model provides practical insights for making informed decisions in electricity markets based on sequential auctions. While the bidding curves submitted to the day-ahead market remain unaffected by scenarios, those submitted to the intra-day market show dependence on fluctuations in day-ahead market prices. • Designing a decision framework for a hybrid electricity/hydrogen station. • Participating in day-ahead and intraday electricity auction markets effectively. • Modeling price uncertainties using scenarios and k-means clustering. • Applying Benders decomposition for day-ahead and intraday bidding decisions. • Using stochastic dual dynamic programming for the Benders sub-problem. [ABSTRACT FROM AUTHOR]

Interest in metal electrodeposition for synthesizing customized nanomaterials has resurged, particularly for applications such as sensors and fuel cells. The present study involved the synthesis of ZnSe nanoparticles (via hydrothermal method) while polypyrrole and novel composite Ppy@ZnSePpy@Ppy (via sequential electrodeposition technique) on a glassy carbon (GC) electrode and their physiochemical, electrochemical, and operando spectro-electrochemical characterizations towards oxygen evolution reaction (OER). Results indicated that ZnSe nanoparticles are well embedded within the Ppy layers and during OER the composite electrocatalyst approached 398 mV at 10 mA cm−2 and exhibited Tafel value (b ∼ 75 mV dec−1) with ECSA (0.03) which shows better results than other two. In addition, the operando spectro-electrochemical spectra of the composite revealed the significant generation of active intermediate oxygen species of selenium and Zn2+. The important feature of the current work is the disclosure of Se's questionable role and species involved in OER found to be Se4+. [Display omitted] • State of art Ppy@ZnSePpy@Ppy composite & its physicochemical characterization has been reported. • Electrodeposition method used for synthesis of composite. • First time operando spectroelectrochemical study was carried out to study OER of Ppy@ZnSePpy@Ppy. • The ambiguous role of Se has been revealed. • As Synthesized composite has shown better candidature towards OER. [ABSTRACT FROM AUTHOR]

Fuel cell hybrid electric vehicles (FCHEVs) are gaining recognition as a pivotal innovation in the quest for sustainable transportation, seamlessly blending the advantages of fuel cells with electric vehicle technology. As global initiatives to curtail greenhouse gas emissions and mitigate climate change gain momentum, FCHEVs offer a promising alternative to conventional internal combustion engine vehicles and battery electric vehicles (BEVs). This review aims to examine recent technological progress in enhancing FCHEV fuel efficiency and performance, focusing particularly on cost reduction, long-distance operational capabilities, and the incorporation of intelligent autonomous systems. A key innovation highlighted in this study is the exploration of cost-effective hydrogen storage techniques, including metal hydrides and chemical storage solutions, which have demonstrated potential to significantly increase storage capacity and reduce refueling times. Furthermore, advancements in energy management, particularly the integration of ultracapacitors and high-capacity batteries, offer new avenues for extending vehicle range and boosting overall efficiency. The emergence of autonomous FCHEVs represents another major leap forward, setting the stage for more efficient, self-driving vehicles in the near future. However, persistent challenges remain, including reducing hydrogen production costs, improving fuel cell durability, and developing a widespread hydrogen infrastructure. Addressing these issues will require ongoing innovation in fuel cell materials, hydrogen storage systems, and energy management strategies. This review underscores the transformative role FCHEVs can play in reducing emissions and enhancing energy efficiency in the transport sector. Collaboration between industry, researchers, and policymakers will be vital to unlocking the full potential of FCHEVs in creating a more sustainable future. • This review work explores the diverse advancements aimed at enhancing the fuel economy and performance of FCHEVs. • A primary focus of recent developments is the reduction of FCHEV costs. • Merging the benefits of hydrogen fuel cells with advanced electric vehicle technology. • The work also looks Fuel Cell Hybrid Electric Vehicles (FCHEVs), offering a promising path achieving sustainable transportation. [ABSTRACT FROM AUTHOR]

In an era marked by escalating environmental concerns and increasing energy demands, the development of advanced, cost-effective polymer electrolyte membrane (PEM) materials is essential to accelerating the widespread adoption of fuel cell technology as a viable and environmentally sustainable alternative to traditional energy sources. To address this challenge, we integrated a novel hybrid nanofiller—fabricated by directly growing TiO 2 nanoparticles on the surface of multi-walled carbon nanotubes (MWCNTs)—into a readily available, cost-efficient polyaromatic polymer, specifically sulfonated polyethersulfone (sPES). The incorporation of the MWCNTs-TiO 2 nanohybrid resulted in significant improvements in the thermo-mechanical stability, swelling capacity, and transport properties of sPES. Ex-situ through-plane proton conductivity measurements demonstrated a peak value of 5.54 mS/cm at 120 °C and 20% RH for PM 5 , representing a tenfold increase compared to unmodified sPES. This enhancement has ascribed to the synergistic effect of the elongated carbon nanotubes and hygroscopic TiO 2 nanoparticles, which fostered the formation of additional proton-conductive pathways within the sPES, maintaining their activity even under dehydrating conditions. Furthermore, the PM 5 nanocomposite exhibited a remarkable peak power density of 87.2 mW/cm2 in the fuel cell (H 2 /air, 120 °C, 30% RH), exceeding the performance of the Nafion benchmark. • A novel MWCNTs-TiO 2 hybrid filler was tested into sulfonated polyethersulfone (sPES). • Direct growth of TiO 2 nanoparticles on the surface of carbon nanotubes was achieved. • Hybrid nanoparticles enhance thermo-mechanical and transport properties of sPES. • Long CNTs with hygroscopic TiO 2 nanoparticles enabled conductivity of 5.54 mS/cm at 120 °C and 20% RH. • Peak power density of 87.2 mW/cm2 for PM 5 in the fuel cell (H 2 /air, 120 °C, 30% RH). [ABSTRACT FROM AUTHOR]

Accurate prediction of the remaining useful life (RUL) of proton exchange membrane fuel cells (PEMFCs) is essential for maximizing their operational lifespan. However, existing methods often face limitations in two key areas: long-term prediction (beyond 168 h, or one week) and adaptability to varying operating conditions. To address these challenges, we propose a novel self-adaptive digital twin (SADT) model for RUL prediction of PEMFCs. Our approach uniquely integrates a deep convolutional neural network to generate robust health indicators (HIs) that maintain consistent monotonicity across diverse operating conditions. Additionally, we introduce a novel quantile Huber loss (QH-loss) function to enhance prediction accuracy and incorporate a transfer learning technique to improve adaptability under varying operational scenarios. Experimental results on PEMFC degradation datasets demonstrate that our method outperforms state-of-the-art techniques in long-term prediction accuracy, highlighting its potential to significantly extend fuel cell lifetimes. • A novel self-adaptive digital twin for predicting RUL of the PEMFC. • Transfer Learning enhanced RUL prediction accuracy and adaptability. • Universal monotonic HI applicable to various PEMFC operating conditions. [ABSTRACT FROM AUTHOR]

In this research, wear resistance of chromium nitride (CrN) coated aluminum alloy with hydrogen charging was investigated. Delamination rates of the CrN coating layer after 6 and 12 h of hydrogen charging were measured to be 42.37% and 86.96%, respectively. In particular, damage by hydrogen attack was observed in the exposed area of aluminum alloy. Increasing in applied load and hydrogen charging time decreased the friction coefficient, and when the two factors interacted, a significantly higher increasing rate of wear damage was observed. The increasing rate in wear depth due to hydrogen charging was greater at the applied of 1 N than at 5 N. This is because hydrogen permeation affects the wear resistance of the CrN coating layer and aluminum alloy in the depth direction. In addition, re-transfer and re-adhesion of the CrN coating, whose adhesion strength had decreased due to hydrogen charging, actively occurred. • The high durability of hydrogen valve is a very important factor for the commercialization of fuel cells. • The surface damage and delamination of the CrN coating layer by hydrogen charging were obviously observed. • The delamination of the CrN coating layer occurred in a bulk, and the wear resistance decreased accordingly. • In particular, hydrogen charging affected the adhesive wear of CrN-coated specimens. • Nevertheless the CrN coating technology is significantly excellent performance for resistance of hydrogen embrittlement. [ABSTRACT FROM AUTHOR]

The global population is increasing, and emerging technologies have led to an unprecedented rise in worldwide energy consumption. Moreover, there is an urgent need to decrease the emission of harmful greenhouse gases linked to the utilization of fossil fuel reserves, which are depleted rapidly. In this context, polymer electrolyte membrane (PEM) fuel cells have emerged as the most promising energy source. One innovative energy system with significant potential is the direct borohydride fuel cell (DBFC), which offers a remarkable energy storage and conversion capacity. This technology has gained significant attention due to its impressive theoretical specific energy, convenient storage capabilities, and environmentally friendly characteristics. The distinctive capabilities of this technology have attracted the interest of both academic and industrial domains, owing to its versatile applicability across a broad spectrum of applications. This article provides thorough insights into the types of PEMs, catalysts, and factors limiting their practical applications in DBFCs. The mechanism of fuel oxidation, degradation, and mitigation measures of PEM in DBFCs are discussed in detail. By highlighting the notable advantages of PEMs in DBFCs, such as their permeability and minimal fuel crossover, ion conductivity, and stability, we demonstrate the significant potential of PEM membranes in DBFCs. Additionally, we have presented several representative examples that showcase the diverse range of potential applications for PEM membranes in fuel cells. Finally, we have addressed key challenges in this field, providing valuable insights for future research endeavours. • Recent advances in polymer electrolyte membranes and catalysts in direct borohydride fuel cell applications are summarized. • The working mechanism, elemental relationship, and transport coefficients are thoroughly elaborated. • Emphasis is targeted on the degradation of membranes in the long run and their mitigation strategies. • Practical viability and sustainability constraints and suggestions are also discussed. [ABSTRACT FROM AUTHOR]

In this study, a novel biodegradable polymer electrolyte membrane with reduced fuel crossover, high selectivity, and high conductivity compared with Nafion 117 membrane in direct ethanol fuel cells (DEFCs) has been reported. Herein, polyvinyl alcohol/epoxidized natural rubber (PVA/ENR) blend membranes were synthesized via a simple solution casting method and applied in DEFCs. The structural and physicochemical features of the PVA/ENR blend membranes were examined using FESEM, FTIR, XRD, water absorption, ethanol uptake, swelling ratio and oxidative stability. ENR enhances the chemical, structural, and mechanical characteristics of PVA, making it a valuable material in fuel cell applications. The incorporation of ENR into the PVA matrix results in a compact morphology, excessive multifunctional groups, low fuel crossover, and high selectivity. The optimum membrane thickness achieves the highest selectivity, reaching up to 12.32 × 104 S s cm−3 at 30°C. Additionally, the maximum power density achieved is 19.52 mW cm−2, surpassing that of the Nafion membrane, which is only 14.55 mW cm−2 at 90°C. Furthermore, this biodegradable membrane can sustain operation for 1000 h at 90°C, owing to its ability to maintain hydration for an extended period. This study represents the first attempt to combine PVA and ENR in fuel cells. [ABSTRACT FROM AUTHOR]

Ni nanoparticles supported on graphene-based materials were tested as catalysts for the oxygen reduction reaction (ORR) to be used in anion exchange membrane fuel cells (AEMFCs). The introduction of N into the graphene structure produced an enhancement of electrocatalytic activity by improving electron transfer and creating additional active sites for the ORR. Materials containing both N and S demonstrated the highest stability, showing only a 3% performance loss after a 10 h stability test and therefore achieving the best overall performance. This long-term durability is attributed to the synergetic effect of Ni nanoparticles and bi-doped (S/N)-reduced graphene oxide. The findings suggest that the strategic incorporation of both nitrogen and sulphur into the graphene structure plays a crucial role in optimising the electrocatalytic properties of Ni-based catalysts. [ABSTRACT FROM AUTHOR]

The fuel cell vehicle is one of the essential directions for developing new energy vehicles. But heat dissipation is a critical technical difficulty that needs to be solved urgently. Nano-coolant is a promising coolant that can potentially replace the existing coolant of a fuel cell. However, its thermal conductivity has a significant impact on heat dissipation performance, which is closely related to nanoparticles' thermal conductivity, nanoparticles' volume fraction, and the nano-coolant temperature. Many scholars have created the thermal conductivity models for nano-coolants to explore the mechanism of nano-coolants' thermal conductivity. At present, there is no unified opinion on the mechanism of the micro thermal conductivity of the nano-coolant. Hence, this paper proposed a novel model to predict the thermal conductivity of ethylene glycol/deionized water-based nano-coolants. A corrected model was designed based on the Hamilton & Crosser model and nanolayer theory. Finally, a new theoretical model of nano-coolant thermal conductivity suitable for fuel cell vehicles was constructed based on the base fluid's experimental data. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is an advantageous polymer due to its renewable nature, low cost, environmental compatibility, biocompatibility, biodegradability, chemical stability, and ease of modification. With these advantages, BC is an interesting candidate for the development of novel eco-friendly materials for proton-exchange membrane (PEM) applications. However, its practical applications have been limited by its relatively high dispersion in water, which usually occurs during the operation of proton-exchange membrane fuel cells (PEMFCs). In addition, the proton conductivity of bacterial cellulose is poor. In this study, functionalized BC modified with 3-aminopropyltriethoxysilane (APTES) was prepared using a solvent casting method to enhance its performance. The results showed that the water stability of the modified BC membrane was significantly improved, with the contact angle increasing from 54.9° to 103.3°. Furthermore, the optimum ratio of BC and APTES was used to prepare a proton-exchange membrane with a maximum proton conductivity of 62.2 mS/cm, which exhibited a power generation performance of 4.85 mW/cm2 in PEMFCs. It is worth mentioning that modified BC membranes obtained by combining an alkaline proton carrier (-NH2) with BC have rarely been reported. As fully bio-based conductive membranes for PEMFCs, they have the potential to be a low-cost, eco-friendly, and degradable alternative to expensive, ecologically problematic fluoric ionomers in short-term or disposable applications, such as biodegradable electronics and portable power supplies. [ABSTRACT FROM AUTHOR]

The climate crisis has become the most serious concern of human beings and environments worldwide in the 21st century. Global concerns about cancer epidemiology mainly originate from anthropogenic activities, particularly fossil-based operations. A key solution to this problem is the use of fuel cells—devices—capable of the direct conversion of fuel chemical energies like urea into electricity. To make their commercialization reasonable, one of the problems that needs to be solved is the development of anodic materials. The majority of investigations on urea oxidation are based on nickel, but its inadequate activity limits the efficiency of these devices. In this work, we propose and synthesize a Ni-Cu-Fe ternary electrocatalyst for urea oxidation through a fast and facile electrodeposition method. The properties of the synthesized material are examined by Scanning Electron Microscopy (SEM) conjugated with Energy Dispersive X-ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD). Its electrochemical properties were also examined in a 1 M KOH solution with and without 0.15 M urea. We found that the prepared powder is active in the electro-oxidation of urea, with 1.65 Vvs RHE required for a current density of 10 mA cm−2 and a stable potential of 2.38 Vvs RHE required for 3 h of polarization at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

With the gradually accelerating pace of global decarbonization, highly efficient and clean proton exchange membrane fuel cells (PEMFCs) are considered to be an energy solution for the future. During the operation of a fuel cell, it is necessary to keep the internal proton exchange membrane in a good state of hydration, so an appropriate method of detecting the hydration state is essential. At present, fuel cell systems are rapidly developing towards high power, but methods for detecting the hydration state of high-power fuel cell systems are still relatively lacking. Therefore, this paper studies the hydration state of high-power fuel cell systems and builds a condensation tail-gas water collection device for calculating the water flow out of a fuel cell system, deriving the hydration status inside the high-power fuel cell system. To verify the proposed water balance model, a series of experiments were conducted based on controlled variables such as working temperature, air metering ratio, and load current. Experiments were conducted on a 100 KW fuel cell system to collect water flow from the fuel cell system. Finally, based on the experimental data, the change rate of the internal water content of the fuel cell system under different conditions was calculated. The results show that, under the same load current, as the working temperature and air metering ratio increase, the change rate of the internal water content of the fuel cell system gradually decreases. Therefore, at low power, it is necessary to maintain an appropriate working temperature, while at high power, maintaining an appropriate air metering ratio is more important. [ABSTRACT FROM AUTHOR]

Hydrogen production from renewable sources is gaining increasing importance for application as fuel, in particular with high efficiency and low impact devices such as fuel cells. In addition, the possibility to produce more sustainable hydrogen for industrial application is also of interest for fundamental industrial processes, such as ammonia and methanol synthesis. Catalytic processes are used in most options for the production of hydrogen from renewable sources. Catalysts are directly involved in the main transformation, as in the case of reforming and of electro-/photo-catalytic water splitting, or in the upgrade and refining of the main reaction products, as in the case of tar reforming. In every case, for the main processes that reached a sufficiently mature development stage, attempts of process design, economic and environmental impact assessment are presented, on one hand to finalise the demonstration of the technology, on the other hand to highlight the challenges and bottlenecks. Selected examples are described, highlighting whenever possible the role of catalysis and the open issues, e.g. for the H2 production from reforming, aqueous phase reforming, biomass pyrolysis and gasification, photo- and electro-catalytic processes, enzymatic catalysis. The case history of hydrogen production from bioethanol for use in fuel cells is detailed from the point of view of process design and techno-economic validation. Examples of steady state or dynamic simulation of a centralised or distributed H2 production unit are presented to demonstrate the feasibility of this technology, that appears as one of the nearest to market. The economic feasibility seems demonstrated when producing hydrogen starting from diluted bioethanol. [ABSTRACT FROM AUTHOR]

The hydrolysis of silicon and its compounds to produce hydrogen for fuel cell remains a major problem. The main obstacle is the weak hydrolytic activity and slow kinetics of silicon. In this work, the alloying properties of Si and Ca to improve its hydrolytic activity, and studied the film breaking effect of different metals and halogen ions on its passivation layer. The results show that the hydrogen production of the alloy is still determined by its phase composition. Among the common metal (Ni, Bi, Sn) and halogen ions (F–, Cl–) catalyzed by hydrolysis, Ni and F– showed a good synergistic effect, resulting in a hydrogen yield of 269 mL/g at room temperature without alkali. The effects of metal ions and halogens on the hydrolytic properties of Ca–Si alloy were investigated, and Ni2+ and F— showed good synergistic effect. [ABSTRACT FROM AUTHOR]

Fuel cells are the most promising energy source for the future energy demand. The automobile industry is looking at the integration of fuel cells with electric vehicles (EV). This integration comes with many challenges like dynamic operational behaviors. For operating the fuel cell with maximum efficiency, this work proposes an Adaptive Neuro Fuzzy Inference System (ANFIS) based Maximum Power Point Tracking (MPPT) method. The hydrogen flow rate, pressure and stack temperature are the parameters considered to track the maximum power point of the fuel cell. The ANFIS-MPPT algorithm has been integrated with the 1.26 kW fuel cell in MATLAB/Simulink® and validated in different scenarios like dynamic variation in hydrogen pressure, stack temperature, load variation. The performance has been observed and compared with the conventional MPPT algorithms of Perturb and Observe (P&O) algorithm and Incremental Conductance (InC) algorithm. The proposed ANFIS-MPPT algorithm improves the power stability by 10–15% than the P&O and InC methods. Also, the proposed ANFIS-MPPT has 30% faster response as compared to the P&O algorithm, and 23% than the InC algorithm. From the analysis, it is observed that the ANFIS, P&O and InC methods are having the response time of 2.5 s, 3.6 s and 4.5 s respectively. Also the ANFIS method delivers the maximum power output of 1.26 kW, whereas the P&O and InC deliver 1.13 kW, 1.19 kW respectively. The detailed simulation analysis and results are presented in this paper. [ABSTRACT FROM AUTHOR]

Summary: A high voltage gain characteristic is required in fuel cell vehicles to achieve voltage matching between low voltage fuel cell and high voltage DC‐link bus. In this paper, a non‐isolated high step‐up dc‐dc converter based on switched‐capacitor (SC) and active‐interleaved‐network (AIN) is proposed. The main advantages of the converter are the high voltage gain without an extremely high duty cycle, automatic current sharing of inductors, reduced input current ripple, and lower device voltage stress when compared to the topologies with the same output voltage. Detailed descriptions of the converter including operation principle and dynamic response analysis are presented in this manuscript. To verify the correctness of the theoretical analysis and feasibility of the proposed converter, a 500 W prototype with 20 V input and 200 V output is built. [ABSTRACT FROM AUTHOR]

Fuel cell technologies constitute a clean, reliable, highly efficient, and eco‐friendly source of alternative energy generation. However, they still require a reliable and robust catalytic system showing comparative electrochemical activity to precious metal Pt with less cost. In this work, Mn@ZnO NPs were synthesized using a hydrothermal‐assisted simple method. Several techniques including SEM, TGA, and XRD were used to confirm the material synthesis. Electrochemical properties were analyzed by using linear sweep voltammetry, chronoamperometry, and cyclic voltammetry. A higher ORR activity in terms of mass activity and current density was observed 133.9 mA/mg as compared to Pt/C (96 mA/mg) and Pd/C (67 mA/mg) under otherwise identical conditions. Mn@ZnO also exhibited excellent current density (1.913 mA cm−2), comparable to Pt/C (1.55 mA cm−2). Chronoamperometry shows stability for up to 800 s. Comparative studies were conducted in both acidic and basic mediums, with observed higher ORR activity in acidic media. [ABSTRACT FROM AUTHOR]

One of the most critical components of a proton exchange membrane (PEM) fuel cell is the gas diffusion layer (GDL). Conventional preparation methods are complex, energy-consuming, and lack design flexibility. Additive manufacturing (AM) is widely used in various fields, with the fused deposition modeling (FDM) technique being the most widely used. With AM, GDLs can be designed and printed with precise control over their structure, porosity, and thickness. Previous research by the authors has shown high electrical resistance of the FDM-printed GDL. Thus, in this study, surface modification of printed GDL was performed to enhance its performance. The FDM-printed GDL with conductive graphite coating demonstrated a desirable breaking factor (2.11 kN/m) and air permeability (326 cm3/cm2/s). Its thickness, mass, and porosity were also determined to be appropriate and customizable. The performance of the manufactured GDL was examined in an open cathode air-breathing PEM fuel cell, indicating good feasibility at room temperature (20 °C). The results show that the application of the FDM technique in GDL manufacturing has great potential to revolutionize the fuel cell industry and drive progress toward a more sustainable future. [ABSTRACT FROM AUTHOR]

At elevated operating temperatures, a large temperature gradient can cause irreparable damage to the solid oxide fuel cells (SOFCs) stack, eventually interrupting the durability of the stack. Metal substrate support could be used to overcome this challenge. However, the application of metal substrate support poses various challenges such as different thermal expansion coefficients, pore diameters, and complex fabrication techniques. Therefore, a first-ever novel and mechanically strong ferritic stainless-steel metal mesh-supported SOFC design is developed to mitigate these challenges. The metal mesh of 200 μm thickness is laminated with tape-casted green films of anode-support, anode functional layer (AFL), and electrolyte films of SOFC. The iso-static pressure of 300 MPa exhibits a firm attachment of the green films of SOFC with the metal mesh. Subsequently, the metal mesh-supported planar SOFC exhibits 3.3 times higher flexural strength compared to the conventional commercial anode-supported planar SOFC. The nano-CuO is added to constituent layers as a sintering aid to attain the maximum density at a lower sintering temperature of 1100 °C. The result shows that the practical application of the metal mesh-supported cell technology has a great potential to overwhelm the mechanical durability of SOFCs. [ABSTRACT FROM AUTHOR]

Power characteristics are important indicators of fuel cell performance. In the actual operation of fuel cells, changes in operating conditions lead to variations in their power characteristics. Therefore, it is imperative to explore the impact of operating conditions on power characteristics. This paper analyzes the factors influencing fuel cell power and uses sensitivity analysis to investigate how different factors affect fuel cell performance. The operating parameters are optimized using a Bayesian-optimized Gaussian process regression model. The research results indicate that temperature has the greatest impact on fuel cell power, followed by stoichiometry and backpressure. The Bayesian-optimized Gaussian process regression model performs the best, reducing its RSME from 0.1 to 0.0556. Residual analysis and regression characteristic analysis verify the optimized model's improved fitting and regression characteristics. Based on the Bayesian–Gaussian process regression model, the optimized operating parameters are obtained for maximum power: a temperature of 80 °C, stoichiometry of 4, and backpressure of 1.7 bar. This paper provides theoretical support for improving fuel cell performance. [ABSTRACT FROM AUTHOR]