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Pt-based alloys, such as Pt3Ni, are among the best electrocatalysts for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. Doping of PtNi alloys with Zr was shown to enhance the durability of the operating ORR catalysts. Rationalizing these observations is hindered by the absence of atomic-level data for these tri-metallic materials, even when not exposed to the fuel cell operation conditions. This study aims at understanding structure–property relations in Zr-doped PtNi nanoparticles as a key to their ORR function. In particular, we calculated, using a method based on density functional theory, the most stable chemical orderings of pristine and Zr-doped Pt3Ni particles containing over 400 atoms. We thus clarify (i) preferential location and charge states of Zr atoms in the Pt3Ni NPs; (ii) effect of doping Zr atoms on the stability of the Pt skin of the Pt3Ni NPs; (iii) charge redistribution induced by Zr dopants; (iv) layer-by-layer atomic ordering in the Pt3Ni/Zr NPs with the increasing Zr content; and (v) effect of Zr atoms on the adsorption energies of O and OH species as indicators of the ORR activity. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) combustion and solid oxide fuel cells (SOFCs) can potentially reduce aviation-produced greenhouse gas emissions compared to kerosene propulsion. This paper outlines a methodology for evaluating performance and emission tradeoffs when retrofitting conventional kerosene-powered aircraft with lower-emissionH2 combustion and SOFC hybrid alternatives. The proposed framework presents a constant-range approach for designing liquid hydrogen fuel tanks, considering insulation, sizing, center of gravity, and power constraints. A lifecycle assessment evaluates greenhouse gas emissions and contrail formation effects for carbon footprint mitigation, while a cost analysis examines retrofit implementation consequences. A Cessna Citation 560XLS+ case study shows a 5% mass decrease for H2 combustion and a 0.4% mass decrease for the SOFC hybrid, at the tradeoff of removing three passengers. The lifecycle analysis of green hydrogen in aviation reveals a significant reduction in CO2 emissions for H2 combustion and SOFC systems, except for natural-gas-produced H2 combustion, when compared to Jet-A fuel. However, this environmental benefit is contrasted by an increase in fuel cost per passenger-km for green H2 combustion and a rise for natural-gas-produced H2 SOFC compared to kerosene. The results suggest that retrofitting aircraft with alternative fuels could lower carbon emissions, noting the economic and passenger capacity tradeoffs.

This study employed Micro X-ray computed tomography (Micro-CT) to reconstruct the gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs) and used lattice Boltzmann method (LBM) simulations to investigate the dynamic behavior of liquid water in the multiscale space of the GDL and gas channel (GC). The results showed that the transport of liquid water from GDL to GC through the interface of GDL-land and GDL-GC were divided into four stages: large pore filling, through-plane breakthrough, in-plane diffusion, and rapid transport into GC. The wettability of GC wall and GDL affects the transport and distribution of liquid water. When the contact angle on the GC wall was less than 90°, it promoted liquid water transport to the top GC wall, resulting in faster internal flow formation. Conversely, contact angles exceeding 90° caused liquid water to break through the GDL-GC interface from pores away from the GC wall. When the contact angle of the GDL was in the range of 110°–150°, both excessively large and excessively small contact angles hindered water transport and management. Maintaining the contact angle of the GDL around 130° enhanced the breakthrough path and transport speed of liquid water into the GC, and it also reduces localized liquid water accumulation. [Display omitted] • The real structure of GDL was reconstructed by Micro-CT scanning. • The dynamic behavior of liquid water in GDL-GC and their interface is studied by LBM. • The wettability of GC and GDL affects the transport and distribution of liquid water. [ABSTRACT FROM AUTHOR]

Efficient reactant distribution and water removal are critical during polymer electrolyte fuel cell (PEFC) operation. The bipolar plate and its corresponding flow field design are vital among the PEFC components for enhancing reactant transport and water removal. The issues arising in the PEFC during the high current operation, such as reactant starvation and water removal, can be alleviated by improving the flow channel geometry. In this study, we analyze the variation in overall PEFC performance and corresponding reactant transport phenomenon for two independent design cases. The converging gradient design without channel traps at 0.4 V operating voltage exhibited a current density increment of 6.85% against the conventional design. Moreover, at 0.4 V, including channel traps enhanced the current density, as we observed a current density increment of 7.1% for the converging design with channel traps against the conventional design without channel traps. Likewise, at 0.4 V, the diverging design with channel traps exhibited a current density increment of 5.85% against the diverging design with no channel traps. Further, enhanced reactant distribution is observed in the catalyst layer upon introducing channel traps in the flow field design. [Display omitted] • Flow field design with the inclusion of channel traps is explored for performance. • Flow channel trap inclusion leads to cell performance increment. • Enhanced reactant distribution under the channel trap region is observed. • Converging design (case-2) attains a maximum current density of 1.38 A/cm2. • Converging (case-2) gains 7.0% current density compared to conventional design. [ABSTRACT FROM AUTHOR]

For cost reduction and environmental‐friendly manufacturing, it is highly demanded to replace the current perfluorinated sulfonic acid‐based membrane in polymer electrolyte membrane fuel cells (PEMFCs) with inexpensive and readily available hydrocarbon‐based (HC) membranes. However, HC membranes suffer from profound dimensional changes caused by swelling and shrinking during operation, especially in automotive applications. These changes lead to severe mechanical degradation and shorten the service life of PEMFC. Herein, a multibar coating system is developed to manufacture HC/polytetrafluoroethylene (PTFE) composite membrane. This system facilitates capillary‐rise infiltration with the aid of an optimal amount of residual alcohol solvent on the PTFE. To address compatibility issues between PTFE and HC‐ionomer solutions, the effects of residual alcohol solvent on tuning the PTFE surface are investigated by controlling systemic parameters and performing diverse mechanical, optical, and electrochemical measurements. Based on its enhanced mechanical toughness (≈30.04%) and superior impregnation properties, the constructed HC/PTFE composite membrane exhibited more than seven‐fold improvement in mechanical durability under repeated accelerated wet–dry conditions compared with an unsupported pristine HC membrane while also mitigating performance loss (≈5.84%). [ABSTRACT FROM AUTHOR]

Airborne NH 3 is a factor in the degradation of proton exchange membrane fuel cell (PEMFC) performance and lifetime. Herein, the spatial characteristics of PEMFC contaminated with NH 3 in galvanostatic and potentiostatic states are investigated by analyzing the local current density, and the effect of relative humidity (RH) during NH 3 contaminates PEMFC is studied by durability curve, polarization curve, and electrochemical impedance spectroscopy testing. The results show that NH 3 leads to an obvious voltage attenuation along with a significant increase in cathode activation and mass transfer impedance. The distribution of relaxation time (DRT) results show that the anode activation is poisoned by cathode NH 3. The voltage attenuation and impedance increase caused by NH 3 are negatively correlated with the RH. At 0%, 25%, 50%, and 75% RH, the voltage decays 19.4%, 10.7%, 8.4%, and 8.1%. The current density attenuation is more severe in potentiostatic state, with a rate of 41.2% and more than 600 mA·cm−2 in the inlet region, which could be related to the low NH 3 concentration and high amount of product water promoting the dissolution of NH 3 in the intermediate and outlet regions. Consequently, it is recommended that the cell be operated in galvanostatic state with high RH to alleviate the effect of NH 3 and resulting inhomogeneous performance. This study experimentally investigated the effects of cathode NH 3 poisoning on the voltage, impedance, distribution of relaxation time, and local current density distribution of PEMFC, aiming to reveal the characteristics and mechanisms of NH 3 poisoning of PEMFC, as well as the effect of relative humidity during this period. [Display omitted] • Reducing the cathode RH aggravates the poisoning effect of NH 3 on PEMFC. • NH 3 causes a significant increase in mass transfer and cathode activation losses. • Cathode NH 3 also causes an increase in anode activation losses. • NH 3 has a more significant poisoning effect near the cathode inlet region. [ABSTRACT FROM AUTHOR]

Currently, hydrogen generation is considered a crucial aspect of sustainable energy production. This paper disscusses the hypothesis that hydrogen generation occurs during the operation of the membrane electrode assembly and is an acceptable and eco-friendly method for producing hydrogen without carbon dioxide. This paper considers the hypothesis by simulating hydrogen generation in fuel cells that rely on fossil fuels using proton fuel cells. The O ptimized H ydrogen G eneration-based R egression (OHGR) model is based on a deep learning architecture. The architecture is based on stacking multiple neural networks with crossover connections that feed information through a pool of activation functions. The OHGR predicts the amount of hydrogen generated in 1 mA cm−2 and can exceed 10–20 mA cm−2 after long-term operation. For given temperatures, pressures, and humidity, which are considered fundamental factors in the hydrogen crossing phenomenon.The OHGR uses a stochastic gradient as an optimization engine that informs the most-recommended values for temperature, pressure, and humidity to generate the optimal amount of hydrogen. In addition, the OHGR model is interoperated to accept the same number of most significant features obtained from the principal component analysis. The OHGR was evaluated using empirical regression evaluation metrics, including the root mean square error, R2, Mean Square Error, and Mean Absolute Error. The optimization process was designed to include the hypothesis and hyperparameters to determine the most significant values for the OGHR and its outcomes. The introduced OHGR model is sufficiently efficient to predict the generated hydrogen with RMSE = 0.220 and R2 = 0.564, indicating an enhancement of the OHGR model compared to recently reported models. Since the sustainability of hydrogen generation is important for energy availability and reducing climate change, the OHGR model is justified using the SHapley Additive exPlanations (SHAP) method to ensure that the model is transparent, reliable, and trustworthy. [Display omitted] • Optimized Hydrogen Generation-based Regression (OHGR) model using a custom architecture. • OHGR predicts generated hydrogen PEM by optimizing temp, pressure & humidity of CNN structure. • OHGR uses an optimization engine to detect most recommended to generate hydrogen. • OHGR accepts same number of significant features by principal component analysis. • XAI is used to ensure transparent, reliable, and trusted of OHGR using SHAP. [ABSTRACT FROM AUTHOR]

Through the use of fuel cells and photovoltaic (PV) solar cells, green energy has become one of the most popular developments in electricity generation in recent years. Accurate modeling of fuel cell and PV cell is critical in the simulation and analysis of energy systems that use both sources. Due to the complexity and nonlinearity of these hybrid systems, the model must be optimized under different operating conditions. In this article, a novel metaheuristic efficient hybrid algorithm is proposed for this purpose. A Hybrid Chaotic Particle Swarm Optimization and Slime Mould Algorithm (HCPSOSMA) has been proposed to estimate the PV/fuel cell system parameters. The hybrid HCPSOSMA algorithm is superior to other algorithms in terms of higher accuracy in searching for optimal solutions and better explorative capability. The problem formulation is based on minimizing the Root Mean Square Error (RMSE) between the calculated values and measured values for both the triple-diode PV model and the proton exchange membrane (PEM) fuel cell. The results show that the hybrid algorithm outperforms other algorithms in determining the best PV/PEMFC parameters that produce accurate V–I and P–I characteristic curves and the RMSE is about 4 × 10–12. Finally, non-parametric tests based on Friedman's ranking, Wilcoxon's rank sum test and Kruskal-Wallis test are implemented to prove the superiority of the proposed hybrid algorithm in the parameter estimation. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive numerical investigation into the degradation mechanisms of High-Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFCs) with a particular focus on catalyst layer degradation. The study integrates advanced models to accurately describe the electrochemistry of platinum and carbon oxidations, crucial processes influencing the cell's performance over time. Additionally, a heuristic model is employed to account for the loss of proton conductivity in the membrane attributed to the depletion of phosphoric acid. The degradation processes are seamlessly integrated into a 3D computational code. By utilizing optimized values for the electrochemical parameters, the numerical simulations demonstrate excellent agreement with experimental degradation observed in an HT-PEMFC operating under steady-state conditions. In addition, the numerical approach offers insights that are not easy to achieve by experimental means, such as the equilibrium of the different oxidation states of platinum and carbon. • HT-PEMFCs catalyst layer degradation is modeled through electrochemical equations. • The phosphoric acid depletion in the membrane is modeled through a heuristic model. • The unknown electrochemical parameters are obtained by solving an inverse problem. • Electrochemical and transport equations are solved in an in-house 3D OpenFOAM module. • Comparisons with experiments prove the validity of the model. [ABSTRACT FROM AUTHOR]

As of now, all over the world is focusing on the Electric Vehicle (EV) technology because its features are low environmental pollution, less maitainence cost required, high robustness, and good dynamic response. Also, the EVs work continuously until the input fuel is provided to the fuel stack. Here, a Proton Exchange Membrane Fuel Cell (PEMFC) is used as an input source to the electric vehicle system because of its merits fast startup, and quick response. However, the PEMFC gives nonlinear voltage versus current characteristics. As a result, the extraction of maximum power from the fuel stack is very difficult. The main aim of this work is to study different Maximum Power Point Tracking Techniques (MPPT) for the DC-DC converter-fed PEMFC system. The studied MPPT controllers are Adjusted Step Value of Perturb & Observe (ASV with P&O), Adaptive Step Size with Incremental Conductance (ASS with IC), Radial Basis Functional Network (RBFN), Incremental Step-Fuzzy Logic Controller (IS with FLC), Continuous Step Variation based Particle Swarm Optimization (CSV with PSO), and Adaptive Step Value-Cuckoo Search Algorithm (ASV with CSA). The selected MPPT controllers' comprehensive study has been in terms of maximum power extraction, tracking speed of the MPP, settling time of the fuel stack output voltage, oscillations across the MPP, and design complexity. From the comprehensive performance results of the hybrid MPPT controllers, the ASV with CSA technique gives superior performance when equated to the other MPPT controllers. [ABSTRACT FROM AUTHOR]

Green hydrogen (H2) is an essential component of global plans to reduce carbon emissions from hard‐to‐abate industries and heavy transport. However, challenges remain in the highly efficient H2 production from water electrolysis powered by renewable energies. The sluggish oxygen evolution restrains the H2 production from water splitting. Rational electrocatalyst designs for highly efficient H2 production and oxygen evolution are pivotal for water electrolysis. With the development of high‐performance electrolyzers, the scale‐up of H2 production to an industrial‐level related activity can be achieved. This review summarizes recent advances in water electrolysis such as the proton exchange membrane water electrolyzer (PEMWE) and anion exchange membrane water electrolyzer (AEMWE). The critical challenges for PEMWE and AEMWE are the high cost of noble‐metal catalysts and their durability, respectively. This review highlights the anode and cathode designs for improving the catalytic performance of electrocatalysts, the electrolyte and membrane engineering for membrane electrode assembly (MEA) optimizations, and stack systems for the most promising electrolyzers in water electrolysis. Besides, the advantages of integrating water electrolyzers, fuel cells (FC), and regenerative fuel cells (RFC) into the hydrogen ecosystem are introduced. Finally, the perspective of electrolyzer designs with superior performance is presented. [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]

Hydrogen energy has been under close scrutiny by countries around the world. At present, the main technologies for utilizing hydrogen energy in transport power systems are hydrogen internal combustion engine (HICE) and proton exchange membrane fuel cell (PEMFC). Since both of them generate a large amount of waste heat, and waste heat recovery technology is one of the most promising means of utilizing waste heat to improve efficiency, this paper makes a comprehensive comparison of the two technologies in composite waste heat recovery (WHR) system in terms of modeled maximum efficiency, full operating condition efficiency and future predicted maximum efficiency. Based on the thermal efficiency analysis, the advantages, disadvantages, and development prospects of the two technologies in composite the WHR system are reevaluated. The results demonstrate that the efficiency of the HICE and PEMFC can be improved by 6.83% and 2.81%, with the use of WHR system, respectively. Under the full range of operating conditions, the HICE-WHR composite system has obvious efficiency advantage in middle-high load working condition, but PEMFC-WHR composite system has obvious efficiency advantage in low load working condition. Both of them will be very competitive and potential technology routes of hydrogen energy utilization for land transportation. [ABSTRACT FROM AUTHOR]

Optimizing both performance and stability under varying relative humidity (RH) conditions is crucial for proton exchange membrane fuel cells (PEMFCs). Therefore, effective management of mass transfer and water is an essential key factor. To further improve performance and stability, this paper reports a novel PEMFC design strategy that introduces carbon nanotube (CNT) sheets with titanium (Ti) deposited onto them as an additional functional layer using the sputtering method. The Ti‐CNT (as Ti‐deposited CNT is abbreviated to Ti‐CNT) sheets are inserted between the catalyst layer (CL) and the gas diffusion layer (GDL). This exhibit enhances performance across all testing conditions (25‐100% RH), which is attributed to their optimal pore structure and hydrophilic properties. It shows up to ≈94% higher power density and ≈60% improvement in charge transfer resistance compared to conventional. Moreover, stability tests conducted under a constant voltage demonstrated that this innovative design strategy significantly reduced degradation, thereby proving its superior stability. This novel design strategy of inserting Ti‐CNTs as a functional layer improves electrochemical performance and stability. [ABSTRACT FROM AUTHOR]

At present, the availability of nonrenewable sources and their usage for electric vehicle technology is reducing gradually because of their disadvantages are more environmental pollution, direct effect on human health, less reliability, and taking more time to start functioning. So, in this article, the proton exchange membrane fuel cell (PEMFC) is considered for the automotive application because of its advantages quick startup, more power density, more safety to handle, high efficiency, and capability of operating at very low operational temperature conditions. However, the drawback of PEMFC is very difficult to identify the accurate MPP position of the fuel system. Here, the improved variable step genetic algorithm is added with the adaptive neuro-fuzzy inference system for tracking the operational point of the proposed system with high efficiency. These hybrid MPPT controller features are easy to understand, more accurate, have a better dynamic response, and have low design complexity. The evaluated proposed MPPT controller operational efficiency, and settling time of the converter voltage at different fuel stack temperature conditions are 98.7402%, and 0.01607 s respectively. Finally, the boost converter is used in this work to enhance the voltage supply capability of the entire system. The proposed system is investigated by applying the MATLAB tool. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cell (PEMFC) parameter extraction is an important issue in modeling and control of renewable energies. The PEMFC problem's main objective is to estimate the optimal value of unknown parameters of the electrochemical model. The main objective function of the optimization problem is the sum of the square errors between the measured voltages and output voltages of the proposed electrochemical optimized model at various loading conditions. Natural rabbit survival strategies such as detour foraging and random hiding are influenced by Artificial rabbit optimization (ARO). Meanwhile, rabbit energy shrink is mimicked to control the smooth switching from detour foraging to random hiding. In this work, the ARO algorithm is proposed to find the parameters of PEMFC. The ARO performance is verified using experimental results obtained from conducting laboratory tests on the fuel cell test system (SCRIBNER 850e, LLC). The simulation results are assessed with four competitive algorithms: Grey Wolf Optimization Algorithm, Particle Swarm Optimizer, Salp Swarm Algorithm, and Sine Cosine Algorithm. The comparison aims to prove the superior performance of the proposed ARO compared with the other well-known competitive algorithms. [ABSTRACT FROM AUTHOR]

To achieve the 8000-h proton exchange membrane fuel cell stack (PEM FCS) life target set by the U.S DoE and promote fuel cell hybrid electric vehicles (FCHEVs) massive introduction in the automotive market, using multi-fuel cell stack (MFCS) systems instead of single-fuel cell stack systems seems to be an interesting solution that deserves to be explored. MFCS systems' concept combines several small FCSs modules instead of using a single high-powered FCS module. The modularity in such systems can be exploited through energy management to improve their durability and extend their good energy-efficiency power range. However, FCSs' multiplicity makes it challenging to implement effective energy management strategies (EMSs). This paper proposes a remaining useful life (RUL) prognostic-based EMS to extend MFCS systems' lifetime while keeping their hydrogen consumption reasonable. For this purpose, a prognostic algorithm is developed to predict PEM FCSs' RUL in real-world automotive application scenarios. Then a rule-based EMS allocates the demand between stacks using prognostic results. The proposed strategy's performance is evaluated on a hybrid MFCS/battery system using Matlab/Simulink's environment. Simulation results show that implementing the proposed strategy instead of conventional EMSs can extend MFCS systems' lifetime by at least a factor of 2.35 while keeping their hydrogen consumption reasonable. © 2001 Elsevier Science. All rights reserved. • A post-prognostic decision-making strategy is proposed for MFCS systems. • RUL predictions are performed in real-world automotive scenarios. • The MFCS system's lifetime is significantly extended with the proposed EMS. • RUL is a suitable parameter for adaptive energy management decision-making. [ABSTRACT FROM AUTHOR]

Yttrium doped cerium oxide (CeO 2 ·Y 2 O 3) was studied as a free radical scavenger for PEMFCs. MEA with CeO 2 ·Y 2 O 3 was compared with MEAs with CeO 2 and without free radical scavenger. MEAs before and after 50 h of open circuit voltage hold accelerated stress test show better performance retention with CeO 2 ·Y 2 O 3 than CeO 2. MEAs with CeO 2 ·Y 2 O 3 and CeO 2 perform better than the pristine MEA without free radical scavenger. ECSA, MA, and EIS of the MEAs were analyzed to confirm the effect of free radical scavengers on MEA performance and durability. XRF confirmed the improved Ce ions retention in MEAs with CeO 2 ·Y 2 O 3 than pure CeO 2 , indicating improved stability of Ce ions after doping with Yttrium. Effluents from the anode and cathode of the fuel cells were collected and analyzed by fluoride ion selective electrodes at 25 h and 50 h of the accelerated stress test. The fuel cell with CeO 2 ·Y 2 O 3 as a free radical scavenger has the lowest fluoride emission rate. Furthermore, the ex-situ Fenton study combined with ICP-MS analysis shows better stability of Ce in CeO 2 ·Y 2 O 3. This study indicates that yttrium-doped cerium oxide has better stability against dissolution and enhances the stability of polymer components against free radicals compared with CeO 2 , which will benefit the long-term durability of the PEMFCs. • Yttrium-doped CeO 2 was studied as a free radical scavenger for PEMFCs. • Ex-situ Fenton test combined with ICP-MS was used to confirm the improved stability of CeO 2 ·Y 2 O 3 compared with CeO 2. • MEAs study showed improved durability with free radicals scavengers. • CeO 2 ·Y 2 O 3 is more active and stable than CeO 2 in MEAs. [ABSTRACT FROM AUTHOR]

The energy sector is currently exploring eco-friendly energy conversion and storage devices, as an alternative to traditional fossil fuel devices. A unique hybrid proton exchange membrane is developed for proton exchange membrane fuel cells (PEMFC) and vanadium redox flow battery (VRFB) application. Polymeric nanocomposite membranes are effective for the selective and controlled transportation of ions between the electrodes. This study utilizes various modifiers such as GO, SGO, SPES, and SiC, to modify the PES polymer matrix. Analysis of the functional groups confirmed the presence of modifiers and hydroxyl groups on the nanocomposite membrane. Additionally, the use of Field Emission Scanning Electron Microscopy (FESEM) validated the existence of honeycomb and sponge-like voids as well as the surface morphology on the membrane surface. The incorporation of modifiers into the nanocomposite membrane matrix serves as a reliable barrier for the transport of vanadium ions, leading to a significant reduction in vanadium ion permeability across the membrane. The mechanical properties and ion exchange capacity of nanocomposite membranes are enhanced, while the permeability of VO2+ decreases compared to that of the bare PES membrane. The enhancement of proton conductivity is further achieved with the utilization of modifiers in PES polymer. As compared to bare PES membrane, PES/SPES + SGO (5%) exhibits less than half the permeability for vanadium, and PES/SiC shows 44.03 % elongation means twice of bare PES membrane. [Display omitted] • Influences of GO, SGO, SPES, and SiC, and functional groups in PEMFCs and VRFB is also studied. • PES/SiC shows 44.03 % elongation means twice of bare PES membrane. • Enhanced the proton conductivity through the utilization of modifiers with PES polymer. • PES/SPES + SGO (5%) exhibits less than half the permeability for vanadium. [ABSTRACT FROM AUTHOR]

Electric trains equipped with efficient electric motors and powered by high-capacity hydrogen fuel cells are a choice of the global transportation industry to accelerate the global transition to a low-carbon transportation system. The operation of distinct vehicle types in varying geographical regions is characterized by unique features. Concurrently, the continually fluctuating demand for electricity necessitates the utilization of fuel cells in conjunction with energy storage devices. Thus, this study centers on examining the role of the PEMFC-supercapacitor direct hybridization system within the authentic driving profile of the subway in the Bangkok metropolitan region. The supercapacitor within the hybridization system serves as an energy management device, enhancing the durability of fuel cells when subjected to diverse load demands associated with train propulsion. In order to validate this hypothesis, an MRT (Mass Rapid Transit) protocol was formulated to emulate and serve as the load demand for the investigation, and then the PEMFC-supercapacitor direct hybridization system was operated using the created profile. Subsequently, the hybridization system undergoes electrochemical characterizations and fuel cell performance tests for diagnostic purposes. Empirical findings validated that the supercapacitor operates as a filter, generating a stable voltage response to varying load requirements, and possesses the capability to assimilate energy originating from regenerative braking. The integration of supercapacitors in stabilizing the operational parameters of proton exchange membrane fuel cells (PEMFCs) has markedly prolonged their operational lifespan. This assertion is substantiated by voltage signal analysis, which demonstrated a negligible increase in surface resistance of merely 0.23%, as depicted by Nyquist plots. Furthermore, cyclic voltammetry revealed that the system attained a peak electrochemical surface area (ECSA) of 0.0089 (106 cm2/mg of Pt). The information presented in this article constitutes data that has been minimally explored in existing research. Specifically, the study concentrates on the practical driving pattern of electric trains. Consequently, experimental results were deemed advantageous for the advancement of heavy-duty electric vehicles. [Display omitted] • Exploring the relationship between the utilization of an energy storage device as a SC and energy generation as a PEMFC. • Establishing a connection between the authentic current profile of an MRT metro system and an accelerated stress test. • Examining the electrochemical reactions within fuel cells, drawing upon operational data from the transportation sector. [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]

The structural tailoring of Pt‐based catalysts into 1D nanowires for oxygen reduction reactions (ORR) has been a focus of research. Mo(CO)6 is commonly used as a morphological modifier to form nanowires, but it is found that it inevitably leads to Mo doping. This doping introduces unique electrochemical signals not seen in other Pt‐based catalysts, which can directly reflect the stability of the catalyst. Through experiments, it is demonstrated that Mo doping is detrimental to ORR performance, and theoretical calculations have shown that Mo sites that are inherently inactive also poison the ORR activity of the surrounding Pt. Therefore, a novel gas‐assisted technique is proposed to replace Mo(CO)6 with CO, which forms ultrafine nanowires with an order of magnitude increase in length, ruling out the effect of Mo. The catalyst performs at 1.24 A mgPt−1, 7.45 times greater than Pt/C, demonstrating significant ORR mass activity, and a substantial improvement in stability. The proton exchange membrane fuel cell using this catalyst provides a higher power density (0.7 W cm−2). This study presents a new method for the preparation of ultra‐long nanowires, which opens up new avenues for future practical applications of low‐Pt catalysts in PEMFC. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells (PEMFCs), as a feasible alternative to replace the traditional fossil fuel-based energy converter, contribute significantly to the global sustainability agenda. At the PEMFC anode, given the high exchange current density, Pt/C is deemed the catalyst-of-choice to ensure that the hydrogen oxidation reaction (HOR) occurs at a sufficiently fast pace. The high performance of Pt/C, however, can only be achieved under the premise that high purity hydrogen is used. For instance, in the presence of trace level carbon monoxide, a typical contaminant during H2 production, Pt is severely deactivated by CO surface blockage. Addressing the poisoning issue necessitates for either developing anti-poisoning electrocatalysts or using pre-purified H2 obtained via a thermo-catalysis route. In other words, the CO poisoning issue can be addressed by either thermal-catalysis from the H2 supply side or electrocatalysis at the user side, respectively. In spite of the distinction between thermo-catalysis and electro-catalysis, there are high similarities between the two routes. Essentially, a reduction in the kinetic barrier for the combination of CO to oxygen containing intermediates is required in both techniques. Therefore, bridging electrocatalysis and thermocatalysis might offer new insight into the development of cutting edge catalysts to solve the poisoning issue, which, however, stands as an underexplored frontier in catalysis science. This review provides a critical appraisal of the recent advancements in preferential CO oxidation (CO-PROX) thermocatalysts and anti-poisoning HOR electrocatalysts, aiming to bridge the gap in cognition between the two routes. First, we discuss the differences in thermal/electrocatalysis, CO oxidation mechanisms, and anti-CO poisoning strategies. Second, we comprehensively summarize the progress of supported and unsupported CO-tolerant catalysts based on the timeline of development (nanoparticles to clusters to single atoms), focusing on metal–support interactions and interface reactivity. Third, we elucidate the stability issue and theoretical understanding of CO-tolerant electrocatalysts, which are critical factors for the rational design of high-performance catalysts. Finally, we underscore the imminent challenges in bridging thermal/electrocatalytic CO oxidation, with theory, materials, and the mechanism as the three main weapons to gain a more in-depth understanding. We anticipate that this review will contribute to the cognition of both thermocatalysis and electrocatalysis. [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]

In this study, a dense Ta-based layer with a thickness of 400 nm was fabricated on SS316N bipolar plates (Ta-SS316N) by using a disproportionation reaction of Ta in a K 2 TaF 7 -Ta(powders)-KCl-NaCl molten salt system at 900 °C for 6 h. According to XRD analysis, the Ta-based layer was mainly composed of metallic Ta as well as Ta 2 N 0.86. In the simulated HT-PEMFC cathode environment, the corrosion current density of Ta-SS316N obtained from the potentiodynamicl polarization curves was 0.96 μA/cm2, which meets the 2025 U S. DOE standard. Compared to the SS316N substrate, Ta-SS316N showed two orders of magnitude higher corrosion resistance and nearly 1 V higher self-corrosion potential, with an interfacial contact resistance of 27.5 mΩ∙cm2, accounting for about one-quarter that of SS316N substrate. This provides a low-cost, easy-to-operate method to prepare Ta-based layer on stainless steel bipolar plates used for HT-PEMFC. [ABSTRACT FROM AUTHOR]

Advanced in situ analyses are indispensable for comprehending the catalyst aging mechanisms of Pt‐based PEM fuel cell cathode materials, particularly during accelerated stress tests (ASTs). In this study, a combination of in situ small‐angle and wide‐angle X‐ray scattering (SAXS & WAXS) techniques were employed to establish correlations between structural parameters (crystal phase, quantity, and size) of a highly active skeleton‐PtCo (sk‐PtCo) catalyst and their degradation cycles within the potential range of the start‐up/shut‐down (SUSD) conditions. Despite the complex case of the sk‐PtCo catalyst comprising two distinct fcc alloy phases, our complementary techniques enabled in situ monitoring of structural changes in each crystal phase in detail. Remarkably, the in situ WAXS measurements uncover two primary catalyst aging processes, namely the cobalt depletion (regime I) followed by the crystallite growth via Ostwald ripening and/or particle coalescence (regime II). Additionally, in situ SAXS data reveal a continuous size growth over the AST. The Pt‐enriched shell thickening based on the Co depletion within the first 100 SUSD cycles and particle growth induced by additional potential cycles were also collaborated by ex situ STEM‐EELS. Overall, our work shows a comprehensive aging model for the sk‐PtCo catalyst probed by complementary in situ WAXS and SAXS techniques. [ABSTRACT FROM AUTHOR]

Introduction: Fuel cell technology is a harbinger of the future for generating electricity due to their high efficiency and low emissions achieved through the direct conversion of chemical energy into electrical energy without combustion. Methods: To optimize the design and performance, a fuel cell model is essential to predict its behaviour in different conditions. This technical note presents a novel physics-based approach, the Young's Double-slit Experiment Optimizer (YDEO), for identifying parameters in Proton Exchange Membrane Fuel Cells. A performance metric is established by formulating an objective function that relies on the summation of squared errors between experimental and estimated values. Results and discussion: The effectiveness of this approach is evaluated through the analysis of four benchmark test cases: Horizon 500 W, BCS500 W, NedstackPS6, and 250 W. The corresponding objective function values for these test cases are 0.011243, 2.065557, 0.011698, and 5.250849, respectively. The simulation results demonstrate the efficacy of the proposed YDEO algorithm when compared with other existing popular and contemporary algorithms in the literature. [ABSTRACT FROM AUTHOR]

Modulating the electronic structure and O-intermediates' chemisorption behavior of Pd metallene with boosted oxygen reduction reaction (ORR) performance is critical to advance proton exchange membrane fuel cells (PEMFCs). Herein, Hf doping Pd metallene (Hf-Pd metallene) is developed for efficient ORR electrocatalysis. Multiple characterizations and theoretical simulations disclose that the Hf dopant located in the inner atomic layers of Hf-Pd metallene could modulate the electronic configuration of Pd, lower the binding energies of the Pd d-band centers toward O-related intermediates, deliver a much reduced overpotential during O* hydrogenation into OH*, and thus enhance the catalytic activity. Consequently, the Hf-Pd metallene delivers superior ORR electrocatalytic activity together with excellent stability, surpassing commercial Pt/C and various advanced Pd-based catalysts. Encouragingly, when utilized as the cathode in a PEMFC, the Hf-Pd metallene achieved the higher maximum power density (722.75 mW cm−2) as compared to Pt/C-based batteries, elucidating the practical application of Hf-Pd metallene in PEMFCs. [ABSTRACT FROM AUTHOR]

Alloying platinum with other 3d transition metals (M) in an organized manner is a proven method to enhance the activity and lifespan of Pt catalysts utilized in proton exchange membrane fuel cells (PEMFC). Herein, a distinct composite has been engineered, featuring structured Pt–Fe intermetallic compounds (L1 2 Pt 3 Fe NPs) supported on an iron-doped sulfur-nitrogen-carbon (Fe-SNC) support. The L1 2 Pt 3 FeNPs function as the primary catalytic core for the oxygen reduction reaction (ORR) instead of the conventional Pt NPs. The sulfur atom on the Fe-SNC can secure L1 2 Pt 3 Fe NPs to prevent their aggregation during elevated temperature and operational phases. Additionally, the presence of S atoms can regulate the electronic configuration of platinum and decrease the bond strength between Pt and oxygen-containing intermediates. Consequently, the L1 2 Pt 3 Fe/Fe-SNC catalyst demonstrates exceptional catalytic efficiency and longevity for ORR with E 1/2 of 0.911 V as well as a mass activity (MA) of 0.47 A/mg Pt. The L1 2 Pt 3 Fe/Fe-SNC maintains outstanding ORR stability (MA form 0.47 A/mg Pt to 0.38 A/mg Pt) after 30,000 cycles of AST. Impressively, the L1 2 Pt 3 Fe/Fe-SNC has a power density of 1.547 W/cm2·H 2 –O 2 and 0.669 W/cm2·H 2 -Air at 0.4 V (cathode Pt loading: 0.04mg Pt /cm2) better than commercial Pt/C in PEMFC single-cell. This work provides new ideas for constructing various PtM intermetallic catalysts. [Display omitted] • L1 2 Pt 3 Fe emerges as a major catalytic core for oxygen reduction reactions. • Synergistic effect between L1 2 Pt 3 Fe and Fe-SNC enhances the catalytic activity. • S atoms can anchor L1 2 Pt 3 Fe to enhance catalytic stability. • L1 2 Pt 3 Fe/Fe-SNC shows great ORR performance in PEMFC. [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 practical applications, the proton exchange membrane (PEM) fuel cell stack is often exposed to wind environment, and the speed and direction of the ambient wind are random. The performance variation of an open-cathode PEM fuel cell under various ambient wind directions and speeds was studied. The results show that when the ambient wind direction is opposite to the cathode reactant or from the side of stack, the stack temperature increases and the stack power decreases finally. Moreover, with the increase in the wind speed, the running time of the stack is shortened significantly. For the ambient wind in the same direction as the cathode gas, the stack power increases at a high current and decreases at a low current. For the given speed and direction of ambient wind, the increased air flow rate of fan could alleviate the interference of ambient wind on the stack performance and temperature. However, while the stack temperature is more than the allowable maximum operating temperature, the stack power declines even though the air flow rate of fan increases. [ABSTRACT FROM AUTHOR]

The optimization of flow channel structures significantly impacts the performance enhancement of proton exchange membrane fuel cells (PEMFCs). In this paper, the influences of the loop radius, inclination angle, and presence of the island in the Tesla valve flow field on the performance of a fuel cell were investigated numerically. The results indicated that increasing the inclination angle and curvature radius of the Tesla valve increased the voltage by 16.3% and 31.1%, respectively, compared to the parallel flow field at 0.8 A/cm2. Elevating the inclination angle amplified the resistance effect exerted by tributaries on the main stream, consequently fostering channel-to-membrane mass transfer. Increasing the curvature radius contributed to a heightened total oxygen concentration, but also led to water accumulation problems. The removal of islands increased the reactant contact area, but also created more dead zones, resulting in an observed improvement compared to the parallel flow field, but only marginal improvements over the basic Tesla flow field. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have become an integral part of modern life, serving both civilian and military applications across various sectors. However, existing power supply systems, such as batteries, often fail to provide stable, long-duration flights, limiting their applications. Previous studies have primarily focused on battery-based power, which offers limited flight endurance due to lower energy densities and higher system mass. Proton exchange membrane (PEM) fuel cells present a promising alternative, providing high power and efficiency without noise, vibrations, or greenhouse gas emissions. Due to hydrogen's high specific energy, which is substantially higher than that of combustion engines and battery-based alternatives, UAV operational time can be significantly extended. This paper investigates the potential of PEM fuel cells as an alternative power source for electric propulsion in UAVs. This study introduces an adaptive, fully functioning PEM fuel cell model, developed using a reduced-order modeling approach and optimized for UAV applications. This research demonstrates that PEM fuel cells can effectively double the flight endurance of UAVs compared to traditional battery systems, achieving energy densities of around 1700 Wh/kg versus 150–250 Wh/kg for batteries. Despite a slight increase in system mass, fuel cells enable significantly longer UAV operations. The scope of this study encompasses the comparison of battery-based and fuel cell-based propulsion systems in terms of power, mass, and flight endurance. This paper identifies the limitations and optimal applications for fuel cells, providing strong evidence for their use in UAVs where extended flight time and efficiency are critical. [ABSTRACT FROM AUTHOR]

Fuel cells, as clean and efficient energy conversion devices, hold great potential for applications in the fields of hydrogen-based transportation and stand-alone power systems. Due to their sensitivity to load parameters, environmental parameters, and gas supply, the performance monitoring and fault diagnosis of fuel cell systems have become crucial research areas. Electrochemical impedance spectroscopy (EIS) is a widely applied analytical method in fuel cell systems. that can provide rich information about dynamic system responses, internal impedance, and transmission characteristics. Currently, EIS detection is primarily implemented by using simple topologies such as boost circuits. However, the injection of excitation signals often results in significant power fluctuations, leading to issues such as uneven temperature distributions within the cell, unstable gas supply, and damage to the proton exchange membrane. To address this issue, this paper proposes a real-time EIS detection technique for a proton exchange membrane fuel cell (PEMFC) system that connects a lithium-ion battery and injects the load voltage perturbation through a triple active bridge (TAB) converter. By applying the small-signal model of the TAB converter and designing a system controller using a decoupling control method, the PEMFC power remains stable after the disturbance injection across the entire frequency range under tests. Furthermore, the lithium-ion battery can instantly track load changes during fluctuations. The proposed EIS detection method can acquire EIS data in real time to monitor the state of the PEMFC. Simulation results validate the effectiveness and accuracy of the proposed method for EIS detection. [ABSTRACT FROM AUTHOR]

High-oxygen-permeability ionomers (HOPIs) are being actively developed to enhance the performance and durability of high-power polymer electrolyte membrane fuel cells (PEMFCs). While methods for evaluating binder performance are well-established, techniques for assessing binder durability and measuring its degradation in situ during the AST process remain limited. This study examines the distribution of relaxation times (DRT) and Warburg-like response (WLR) methods as in situ analysis techniques during the catalyst-accelerated stress test (AST) process. We conducted catalyst-ASTs (0.6–0.95 V cycling) for 20,000 cycles, monitoring changes using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Contrary to expectations, during the catalyst-AST, the ion transport resistance of the binder decreased, indicating no binder degradation. Scanning electron microscopy/energy dispersive spectrometer (SEM/EDS) analysis revealed that the degradation rate of the catalyst and the support was relatively higher than that of the binder, leading to a reduction in catalyst layer thickness and improved binder network formation. By applying the DRT method during the catalyst-AST process, we were able to measure the increase in oxygen reduction reaction (ORR) resistance and the decrease in proton transport resistance in situ. This allowed for the real-time detection of the reduction in catalyst layer thickness and improvements in ionomer networks due to catalyst and support degradation. These findings provide new insights into the complex interplay between catalyst degradation and binder performance, contributing to the development of more durable PEMFC components. [ABSTRACT FROM AUTHOR]

Perfluorosulfonic acid (PFSA) polymers are used as electrolyte membranes in polymer electrolyte fuel cells. To investigate the effect on proton conductivity through structural orientation control, we added 1,2,4-triazole to PFSA films during casting to impart anisotropy to the ion-cluster structure of the films. The proton conductivities of the films were found to be high in the film-surface direction and low in the film-thickness direction. Structural analysis using small-angle X-ray scattering suggested that the anisotropy in proton conductivity was due to anisotropy in the ion-cluster structure, which in turn was attributed to the formation of a phase-separated structure via strong bonding between sulfonic acid groups and 1,2,4-triazole during cast film formation and the surface segregation of fluorine. We expect the findings of this study to aid in the fabrication of PFSA films with controlled ion clusters. [ABSTRACT FROM AUTHOR]

The effect of surface roughness on the interfacial contact resistance (ICR) and the corrosion behavior of 446 stainless steel in simulated anode environments for proton exchange membrane fuel cell (PEMFC) (i.e., 0.5 mol L−1 H2SO4 + 2 ppm F− and 5 × 10−4 mol L−1 H2SO4 + 0.1 ppm F− bubbled with hydrogen gas at 80 °C) was investigated by means of atomic force microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy and ICR test. The surface roughness (Ra) produced by mechanical grinding increases noticeably with the decrease of sandpaper grit size from 1000# to 240#. 446 stainless steel shows the active state under free corrosion conditions in the two test solutions and the passive state at the typical anode working potential of PEMFC after the activation-passivation transition. The corrosion resistance decreases with the increase of roughness in both solutions. The corrosion product films formed in the solution with lower acidity are more protective, leading to the appearance of the diffusion process. The enlargement of surface roughness results in the gradual reduction of ICR, but the acceleration of active and passive dissolutions. [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]

An inexpensive membrane with high proton conductivity and high fuel cell performance, which can be an alternative to Nafion for PEMFC (Proton exchange membrane fuel cell), will overcome the obstacle to widespread commercialization of fuel cells due to high cost. For this purpose, SPEEK (sulfonated polyether ether ketone)-PVA (polyvinyl alcohol) blend membranes with colloidal silica additives were synthesized in this study. Ludox AS-40 was used as the colloidal silica source and the blend membrane was prepared by solution casting method. Water uptake capacity, swelling property, size change, dynamic mechanical analysis, ion exchange capacity, AC impedance analysis, hydrolytic and oxidative stability experiments of the synthesized Ludox additives blend membranes for fuel cell application were carried out, and the membranes were also characterized by FTIR (Fourier transform infrared) analysis. While the water uptake capacities of SPEEK/PVA membranes containing 1% Ludox, 5% Ludox, and 10% Ludox at room temperature were found to be 14.08%, 14.84%, and 16.6%, respectively, the water uptake capacities at 80oC increased to 14.73%, 15.17%, and 17.11%. The proton conductivities of 1% Ludox, 5% Ludox and 10% Ludox doped SPEEK/PVA membranes at 80oC were 0.25 S/cm, 0.56 S/cm, and 0.65 S/cm, respectively. Similarly, ion exchange capacities were determined to be 1.41 meq/g, 1.63 meq/g, and 1.71 meq/g, respectively. All Ludox-added membranes exhibited excellent hydrolytic stability, retaining approximately 88% of their mass after 650 h. In addition, in oxidative stability experiments carried out in 4 ppm Fe+ 2 at 80oC, the 10% Ludox-added membrane exhibited the highest weight loss of 88.8% at the end of 24 h, while the 5% Ludox-additive membrane retained 91.6% of its total weight. Considering the proton conductivity and longevity tests of the synthesized membranes, they are thought to be promising structures. [ABSTRACT FROM AUTHOR]

The catalyst layers (CLs) electrode is the key component of the membrane electrode assembly (MEA) in proton exchange membrane fuel cells (PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, ionomer, and Pt nanoparticles, all immersed together and sprayed with a micron-level thickness of CLs. They have a performance trade-off where increasing the Pt loading leads to higher performance of abundant triple-phase boundary areas but increases the electrode cost. Major challenges must be overcome before realizing its wide commercialization. Literature research revealed that it is impossible to achieve performance and durability targets with only high-performance catalysts, so the controllable design of CLs architecture in MEAs for PEMFCs must now be the top priority to meet industry goals. From this perspective, a 3D ordered electrode circumvents this issue with a support-free architecture and ultrathin thickness while reducing noble metal Pt loadings. Herein, we discuss the motivation in-depth and summarize the necessary CLs structural features for designing ultralow Pt loading electrodes. Critical issues that remain in progress for 3D ordered CLs must be studied and characterized. Furthermore, approaches for 3D ordered CLs architecture electrode development, involving material design, structure optimization, preparation technology, and characterization techniques, are summarized and are expected to be next-generation CLs for PEMFCs. Finally, the review concludes with perspectives on possible research directions of CL architecture to address the significant challenges in the future. [ABSTRACT FROM AUTHOR]

Energy efficiency is a global need to decrease net emissions and optimise the use of renewable energy sources. Ongoing research focuses on optimizing the use of renewable energy resources to maximize their consumption. Fuel cells, which utilise water to generate electricity, are among these renewable energy resources. Nevertheless, as previously said, there is ongoing research focused on optimising the synthesis of hydrogen and the extraction of voltage and current. In this study, we present the utilisation of sodium hydroxide (NaOH) in the extraction of hydrogen and silica nanoparticles for the enhancement of power values. The experiment clearly demonstrates that using a 50% NaOH solution resulted in the production of about 5.602 litres of hydrogen gas. Furthermore, the molar percentage of hydrogen in the final product was determined to be 85.74%. The gas chromatography analysis findings indicate that the product contains 81.58% hydrogen, 11.62% nitrogen, and 0.04% carbon dioxide. The electrical efficiency achieved is 86% with a heat loss of 13.96%. In addition, the research included the introduction of silica nanoparticles into the water. It was noted that this led to an increase in power density when the relative humidity was about 70%. The study also revealed that these nanoparticles had the potential to boost fuel cell performance. [ABSTRACT FROM AUTHOR]

This study introduces a multi-scale convolutional neural network (MCNN) for diagnosing various faults in proton exchange membrane fuel cell (PEMFC) systems. Using simulated fault data from a 240 kW PEMFC stack, the MCNN method is validated. Compared to traditional methods like backpropagation neural network (BP), support vector machine (SVM), and temporal convolutional neural network (TCNN), MCNN achieves an average accuracy of 96.31%, outperforming BP (88.88%), SVM (90.67%), and TCNN (93.80%). The study demonstrates MCNN's effectiveness in diagnosing recoverable faults, fatal faults, and multiple faults in PEMFC systems, achieving fault diagnosis accuracies of over 97%. By leveraging its inherent advantages such as multi-channel processing, automatic feature learning, and parameter sharing, MCNN provides an effective solution for accurately diagnosing faults in PEMFC. The utilization of these advantages has enabled MCNN to perform efficient and accurate fault diagnosis in PEMFC systems. • MCNN achieves 96.31% accuracy, surpassing BP, SVM, and TCNN in diagnosing faults. • MCNN achieves over 97% accuracy in categorizing recoverable, fatal, and multiple faults. • MCNN provides swift and accurate fault diagnosis in PEMFC systems. [ABSTRACT FROM AUTHOR]

In this work, a numerical approach is presented to reconstruct the ionomer three-dimensional distribution in the microstructure of the cathode catalyst layer (CCL) of a polymer electrolyte membrane fuel cell (PEMFC) from a 3D segmented image of the CCL obtained by focused ion beam-scanning electron microscopy (FIB-SEM). Three forms of ionomer are distinguished: the ionomer filaments, the coating ionomer and the inter-carbon grains ionomer. The ionomer filaments are identified by applying a filtering procedure to the size distribution in the segmented solid phase obtained via a maximum sphere inscription algorithm. The coating ionomer is reconstructed via a filtering procedure of the curvature distribution computed over the interface between the two segmented phases from the consideration that concave regions are preferential ionomer accumulation zones during the drying step of the CCL fabrication procedure. This procedure of coating controlled by the local curvature is applied until a desired value of coverage is reached. In a last step, catalyst nanoparticles, also not visible in the FIB-SEM image, are reconstructed in the image. • Ionomer coating is numerically reconstructed in a FIB-SEM image. • The ionomer coating is of variable thickness. • A small fraction of the ionomer forms protrusions in the pore space. • A significant fraction of the ionomer is in between the carbon grains. [ABSTRACT FROM AUTHOR]

The present article introduces and investigates a new approach for shaving the peak electricity demand and mitigating energy instability. At the heart of this concept is a smart integration for efficient hydrogen production/storage/usage to minimize energy costs and maximize the renewable penetration in the local electricity grid. The system is driven by a wind farm integrated with proton exchange membrane (PEM) electrolyzers and reverse osmosis desalination units for efficient electricity, hydrogen, and freshwater production. It also combines with PEM fuel cells equipped with a hydrogen tank to meet the demand constantly when renewable electricity is unavailable or unstable. The system's practicality is assessed and compared for various Swedish cities with high wind potential from thermodynamic, economic, and environmental aspects to see where it works effectively. The comparative results of various scenarios show that integrating 32 wind turbines, 2 electrolyzers, and 2 reverse osmosis units, with 25% of electricity going to electrolyzers, 20% to reverse osmosis, and 55% to the grid, is the most optimal configuration/allocation. Optimal locations for the power plant are identified in Visby, Halmstad, and Lund due to favorable wind conditions. Setting up the system in Visby could prevent 1878.2 tonnes of CO 2 emissions, generate 93,910 MWh of electricity annually, and create 213 ha of green space. The proposed system in Visby could boast the biggest electricity generation capacity, reaching 11,263 MWh, sufficient to power 938 households. Scaling this model to 12 cities in Sweden could provide the electricity needs of 4500 households, demonstrating the potential for widespread impact. • A novel strategy for peak electricity shaving and wind stability is introduced. • Wind turbines are intelligently integrated with fuel cells to reduce costs. • The system's practicality is compared for various Swedish cities from all facets. • The system in Visby produces 94 GWh of electricity, avoiding 1878 tons of CO 2. • This strategy offers sustainable energy to 4500 homes if scaled up to 12 cities. [ABSTRACT FROM AUTHOR]

Visualizing the electrochemical and temperature distribution characteristics inside proton exchange membrane fuel cell (PEMFC) should greatly contribute to the product development and performance optimization. In the study, a customized 27-segment 108 cm2 fuel cell was fabricated based on the printed circuit board methodology to achieve the local current density and local voltage measurement. In addition, 27 thermocouples were embedded in the segmented cathode graphite gas flow plate for local temperature measurement. Detailed information of fuel cell core components, multi-channel data acquisition system, external temperature control system, and uncertainty analysis was presented. According to the test results of 4000 s current rising conditions and 2400 s current decreasing conditions, the measurement deviation of total current between data acquisition system and TOYO test station is 2.4%–3.2%. Meanwhile, the deviation of output voltage ranges from 0.1% to 2.6%. To quantify the degree of distribution non-uniformity, the range and standard deviation of local parameter values as well as contour map are demonstrated. The non-uniformity of local current density and local temperature becomes more significant under higher operating current conditions. Furthermore, the degree of parameter non-uniformity is more noticeable under current rising conditions compared with current decreasing conditions. The transient increase of operating current leads to the sudden overshoot phenomena of local current range, and the change of local current density among all segments is instantaneously finished. However, the range of current demonstrates relatively smooth transition trends when reactant flow rate rises. Higher temperature area appears in the middle of membrane electrode assembly, especially in the position with higher local current density. The parameter distribution and transition characteristics could provide helpful guidance for fuel cell optimization and diagnosis. • A 27-segment 108 cm2 fuel cell was fabricated for visualizing distribution characteristics. • Measurement deviation of total current and voltage is 2.4%–3.2%, 0.1%–2.6%, respectively. • Degree of parameter non-uniformity is more noticeable under current rising conditions. • Change of current among all segments is instantaneously finished if the total current varies. • Range of local current demonstrates smooth transition trends when reactant flow rate rises. [ABSTRACT FROM AUTHOR]

Metal hydride based thermally driven systems have attracted significant attention for storing and transporting hydrogen due to their higher energy density. However, their utility can extend to other diverse applications, such as space heating and fuel cell integration, due to their inherent MH formation or decomposition processes. In this perspective, the objective of the present study is to analyse the hydrogen storage or release behavior and thermal characteristics of a newly developed La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 using an annular finned MH reactor under various operating conditions. The absorption outcomes revealed that La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 stored a maximum hydrogen storage capacity of 1.35 wt.% in 1237 s while releasing heat with an average heat output rate of 104.4 W/kg MH at a supply inlet pressure of 25 bar. Also, the achieved peak temperature gain of 14.6 K under similar conditions indicates its utilization in space heating applications, especially in cold countries. The outcomes of desorption at constant pressure indicate that La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 demonstrated 96 % reversibility by releasing 1.31 wt.% of hydrogen in 4509 s with an average heat input rate of 36.4 W/kg MH when operating at a HTF temperature of 303 K. Further, the MH reactor was capable of supplying hydrogen at a discharge rate of 13 lpm for 123.5 min at 323 K HTF temperature, ensuring its possible integration with a 1-kW PEM fuel cell. Further, the La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 achieved gravimetric and volumetric storage densities of 0.76 % and 24.6 kg/m3 of H 2. Moreover, La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 showed excellent reversibility and exhibited superior desorption characteristics compared to La 0.7 Ce 0.1 Ca 0.3 Ni 5. • Hydrogen storage and thermal characteristics of La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 were analysed. • The La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 stored 1.36 wt% in 1237 s at 25 bar feed pressure. • The La 0.7 Ce 0.3 Fe 0.75 Ni 4.25 released 1.34 wt% in 2324 s at HTF temperature of 323 K. • At 13 lpm discharge rate and 303 K, the reactor released 94 % of hydrogen. • The reactor achieved a heat discharge effectiveness of 0.88 at 25 bar supply pressure. [ABSTRACT FROM AUTHOR]

The development of high active and stable Pt−M (M=transition metals) electrocatalysts for oxygen reduction reaction (ORR) is crucial for the commercialization of proton exchange membrane fuel cells (PEMFCs). The main challenge of Pt−M electrocatalysts is their instability, mainly due to the leaching of M. In this study, we report the design of P and O co‐doped octahedral PtCo alloy on Ketjen carbon black (Px‐Oct PtCo/C) through a seed‐mediated synthesis. In‐situ FTIR spectroscopy revealed that P0.61‐Oct PtCo/C has the lowest d‐band center, thereby enhancing the catalytic activity. The strong interaction formed by chemical bond between O and Co in Px‐Oct PtCo/C, observed by EXAFS spectra effectively inhibited the dissolution of Co and improved the ORR stability. The mass activity and specific activity of P0.61‐Oct PtCo/C can reach 0.61 A mgPt−1 and 2.4 mA cm−2, respectively, which is 4.1 times and 10.9 times higher than that of commercial Pt/C. After 50,000 potential cycles, the loss of mass activity is only 25 %, surpassing the DOE 2025 target of less than 40 % loss after 30,000 cycles. This study offers an alternative approach to enhancing the activity and durability of Pt−M electrocatalysts for the ORR. [ABSTRACT FROM AUTHOR]

Multi‐walled carbon nanotubes (MWCNTs) with excellent physiochemical properties have been recently applied to energy/power generation and storage systems encompassing polymer electrolyte membrane fuel cells (PEMFCs). However, there is a lack of investigations of the properties of MWCNT composites themselves under the actual operating conditions of systems. In this paper, MWCNTs/polytetrafluoroethylene (PTFE) composites were fabricated as electric and hydrophobic components for energy/power systems. The electrical properties, heating behavior, hydrophobicity, and water evaporation behavior of the composites are characterized within the operating voltage ranges of PEMFC. With 50% MWCNT content, the conductivity and the contact angle were 11.83 S/cm, and the contact angle 128.1°, respectively. The MWCNT/PTFE composite film showed a linear temperature rise with voltages and rapid temperature saturation within 40 s. The rate in the initial heating range was measured at 0.5°C/s for the voltage of 0.5 V. The voltage increase induced an exponential decrease in the height of water droplets on the composite surface. The evaporation rate increased almost 10‐fold, from 0.013 mm/min at 0.0 V to 0.12 mm/min at 1.0 V. The proposed characteristics of the functional composite provide insights into the material requirements for electrochemical devices, including PEMFC. Highlights: Multi‐walled carbon nanotube/polytetrafluoroethylene composites can be applied to energy storage and power generation.Key properties of the composites are proposed for polymer electrolyte membrane fuel cell (PEMFC) operating conditions.The composite has a fast heating by high conductivity and temperature uniformity.Water‐vapor transformation under PEMFC operating voltage is quantified. [ABSTRACT FROM AUTHOR]

Analyzing degradation heterogeneity of proton exchange membrane fuel cell (PEMFC) while maintaining high practicality is consistently challenging, primarily due to the destructive and costly nature of existing techniques relying on material characterization. In this work, a designed magnetic array integrating 16 sensors within 25 cm2 space is used for direct scanning and imaging of PEMFC performance heterogeneity during its degradation. Results are validated through degradation mechanism analysis and material characterization, confirming its potential in guiding the development of durable materials. [ABSTRACT FROM AUTHOR]