Structure-based prediction of gas diffusion property of catalytic layer of proton exchange membrane fuel cells via manifold learning and X-ray ptychographic nano-computed tomography

This study systematically investigates a synergistic catalyst–ionomer design strategy integrating catalyst architecture, support chemistry, and ionomer structure to enable proton exchange membrane fuel cell (PEMFC) performance relevant to heavy-duty applications. A non-commercial PtCo alloy catalyst supported on nitrogen-doped mesoporous carbon (PtCo/MFCS) enhances intrinsic oxygen reduction reaction activity via alloying while promoting ionomer dispersion, proton accessibility, and favorable interfacial interactions through surface nitrogen functionalities. In parallel, a short-side-chain perfluorosulfonic acid (SSC PFSA) ionomer (Aquivion® D79) is introduced to improve proton conductivity and water retention under low-humidity conditions. In a systematic MEA campaign, PtCo/MFCS delivers over 16 × higher mass activity at 0.9 V (537 vs 32 mA mg Pt −1 ) than a commercial Pt/Vulcan catalyst, despite 43% lower Pt loading, supported by higher electrochemically active surface area and improved dispersion. Beyond kinetic gains, the mesoporous nitrogen-doped support enhances mid-to-high current density performance by facilitating oxygen transport and water management. Replacing Nafion® with Aquivion® D79 further sustains performance under partial humidification down to 33% RH, demonstrating that SSC ionomer benefits emerge only when coupled with appropriate support porosity and chemistry. Overall, the results reveal strong catalyst–support–ionomer synergy, enabling robust, balance-of-plant-friendly PEMFC operation and offering a credible pathway toward U.S. Department of Energytargets for heavy-duty fuel cell. • PtCo/N-doped carbon shows >16 × higher mass activity than commercial Pt/Vulcan. • Mesoporous N-doped support enhances ECSA, Pt utilization, and oxygen transport. • PtCo catalyst outperforms Pt/Vulcan at 2 bar(abs), revealing pressure dependence. • Short-side-chain PFSA ionomer improves PEMFC performance at low humidity (33–50% RH). • EIS confirms reduced ohmic and charge-transfer resistances versus baseline MEA.

The aim of this paper is to develop and evaluate a nature-inspired metaheuristic strategy for Maximum Power Point Tracking (MPPT) strategy in Proton Exchange Membrane Fuel Cells (PEMFCs), whose efficiency is highly sensitive to dynamic operating conditions such as cell temperature and the partial pressures of hydrogen and oxygen. These fluctuations continually shift the system’s Maximum Power Point (MPP), necessitating adaptive control methods to maintain optimal power extraction. This study introduces a novel MPPT technique based on the Horse Herd Optimization Algorithm (HOA), a recent bio-inspired metaheuristic modeled on the social behavior of horse populations. To the best of our knowledge, this work presents the first application of HOA to PEMFC systems. A comprehensive dynamic model is constructed, integrating the electrochemical characteristics of a 50 kW PEMFC stack, a DC-DC boost converter, and an adaptive MPPT controller guided by HOA. The algorithm adjusts the converter’s duty cycle by mimicking behavioral mechanisms—such as grazing, hierarchy, sociability, imitation, defense, and roaming—organized across age-based groups to enhance convergence speed and accuracy. The effectiveness of the HOA-based MPPT is benchmarked against the Cuckoo Search Optimization (CSO) method under various conditions, including standard operation, temperature variations (328 K to 348 K), and pressure fluctuations (1.0–2.0 atm). Simulation results using MATLAB/Simulink demonstrate that the HOA algorithm achieves superior performance, with a maximum power point tracking efficiency of 99.7 % compared to 99.64 % for CSO. Additionally, HOA exhibits a significantly faster settling time of 0.0570 s, outperforming CSO's 0.12 s, and maintains comparable rise times ( 0 . 0016 s ) while eliminating voltage and current oscillations. Under varying thermal and pressure conditions, HOA demonstrates exceptional robustness, rapid convergence, and high stability, maintaining optimal power delivery where conventional methods degrade. This work represents the first successful integration of the Horse Herd Optimization Algorithm into MPPT control for PEM fuel cells and demonstrates its superiority over both traditional and intelligent techniques. It offers a highly efficient and adaptive solution, with promising prospects for future scalability and deployment in real-world fuel cell energy management systems. • First study applying Horse Herd Optimization Algorithm for MPPT in PEM fuel cells, introducing bio-inspired control. • Proposed HOA-based MPPT achieves 99.7% efficiency and 50% faster settling than Cuckoo Search Optimization. • Models six horse behaviors—grazing, hierarchy, sociability, imitation, defense, and roaming—for adaptive MPPT. • Maintains stable power tracking across 328–348 K temperature and 1–2 atm pressure variations. • Opens a new direction for real-time, scalable optimization in hydrogen energy systems.

Sulfonated poly(arylene ether ketone) with pendant phenyl groups as membranes and ionomers for proton exchange membrane fuel cells (PEMFCs)

Developing highly efficient and low-platinum (Pt) proton exchange membrane fuel cell (PEMFC) stacks is imperative for their commercialization. However, ultralow-loading Pt catalysts (<0.10 mg cm-2) are inherently less active and unstable due to high oxygen resistance, particularly under practical stack operating conditions. Here, we present a molybdenum oxide-pocket-driven Pt2Co (MoO3-Pt2Co) alloy to tackle the aforementioned challenge, where MoO3 with abundant oxygen vacancies can act as the pivotal "oxygen storage pocket" to boost the oxygen reduction reaction (ORR) activity and minimize the leaching of Co. Consequently, the MoO3-Pt2Co/C-based membrane electrode assembly (MEA) enables exceptional peak power densities of 3.20 W cm-2 and 1.73 W cm-2 in H2-O2 and H2-air, respectively, with a low Pt loading of 0.10 mg cm-2, outperforming cutting-edge MEAs. Meanwhile, the MoO3-Pt2Co/C-based MEA can retain a record-breaking mass activity of 1.68 A mg-1 after 30k-cycle accelerated stress tests and can be operated stably at 0.65 V beyond 550 h. Most importantly, we develop a MoO3-Pt2Co/C-based fuel cell stack that delivers an excellent rated power of 123 W in H2-air, which can project Pt utilization of 0.0975 gPt kW-1 for a 100-kW hydrogen fuel cell vehicle, exceeding the US Department of energy (DOE) ultimate target of 0.10 gPt kW-1.

A Model for Water Transport in the Membrane and an Impedance Spectroscopy Study of the Effect of Relative Humidity on PEM Fuel Cell Parameters

The sluggish kinetics and insufficient durability of platinum-based catalysts remain crucial barriers limiting proton-exchange-membrane fuel cells (PEMFCs) deployment. Here, we report a theory-guided synthesis combined with rare-earth templating to realize a previously inaccessible Pt5Co-like phase with tailored atomic-scale strain. Guided by density functional theory (DFT) calculations, we identified that a Pt5Co-like sublayer can induce a unique mild compressive strain (-1.24%) to the Pt(111) shell and an optimal *OH binding energy shift (ΔE ≈ 0.11 eV). This shift positions the alloy catalyst near the apex of the oxygen reduction reaction activity volcano. This prediction guided the synthesis of ternary alloy Pt5(Ce)Co@Pt multilayer nanoparticles, featuring a Ce-stabilized core, a Pt5Co-like sublayer, and a Pt-rich shell. This catalyst demonstrates both exceptionally high activity and durability, achieving a mass activity of 2.6 A∙mgPt -1 in rotating disk electrode testing. In fuel cell membrane electrode assembly tests, Pt5(Ce)Co@Pt achieves a current density of 1.9 A∙cm-2 at 0.7V under heavy-duty vehicle conditions. Remarkably, it maintains 1.2 A∙cm-2 after 180000 AST cycles, doubling the U.S. DOE 2025 target. This work demonstrates a rational design strategy that DFT-guided strain engineering integrates with rare-earth templating to advance Pt-based catalysts for fuel cell applications.

Developing cost-effective proton exchange membrane fuel cells (PEMFCs) is imperative yet challenging with respect to the performance of Pt-based membrane electrode assembly (MEA) when using an ultralow Pt loading. Here, we report a hybrid fuel cell catalyst comprising a Pt-skin Pt3Mn intermetallic on a manganese-nitrogen-carbon (Mn-N-C) support. The successful synthesis of this hybrid catalyst relies on the rational use of metal phthalocyanine molecules that serve as a chemical source for the synthesis of Pt3Mn and the construction of Mn-N-C. Pt3Mn/Mn-N-C demonstrates high mass activity (1.22 A mgPt-1) with an ultralow Pt loading of 0.025 mgPt cm-2 and retains 76.3% of its mass activity after 30000-cycle accelerated stress tests (ASTs). Mechanistic investigations and theoretical calculations imply that the synergistic contribution of Mn-N-C networks and structurally stable Pt-skin Pt3Mn hybrid catalysts with enhanced Mn specific anchoring is responsible for achieving high activity and durability in fuel cells.

To improve the performance and stability of proton exchange membrane fuel cell (PEMFC), this paper proposes a hybrid control strategy that integrates sliding mode control (SMC) with model predictive control (MPC). Based on a control framework that combines global optimization with local compensation, the proposed method optimizes PEMFC operating conditions while improving system robustness. A PEMFC air supply subsystem model was developed in Simulink to conduct numerical simulations of SMC, MPC, and the hybrid control strategy. The results show that the hybrid approach achieves the smallest overshoot, reduced by 60% and 28% compared with SMC and MPC, respectively. It also attains the shortest settling time, decreased by 20% and 52%, and the fastest disturbance recovery time, improved by 50% and 37.5%. Overall, the hybrid strategy improved dynamic metrics for oxygen excess ratio, voltage stability, and net power under tested load steps.

Proton exchange membrane water electrolyzers (PEMWEs) has become a promising clean energy technology. The development of highly active and stable Ru-based catalysts with high oxygen evolution reaction (OER) activity is crucial to the practical application of PEMWE because of the rare and high cost Ir. Moreover, the high performance OER catalyst could be used in anode to improve the anti-reversal performance for proton exchange membrane fuel cell (PEMFC). In this work, the RuMnSnOxcatalyst exhibits 166 mV overpotentials at 10 mA cm-2for OER while only 1.2% performance loss after 1000 cycles in acid medium. The PEM electrolyzers based on RuMnSnOxachieves 1.998 V at 2 A cm-2and stably operate over 50 h. The PEMFC peak power density based on Pt/C + RuMnSnOxcatalyst reaches 2.61 W cm-2and the anti-reversal time reaches 143 min.

Fuel cell systems experience continuous performance degradation due to harsh operating conditions, which limits their durability and reliability. This paper therefore aims to examine the main causes and mechanisms of degradation affecting fuel cells, and in particular Proton Exchange Membrane Fuel Cells (PEMFCs), by conducting a detailed Failure Mode, Effects, and Criticality Analysis (FMECA). Each failure mode is assessed through the Fuzzy Risk Priority Number (FRPN), enabling the identification of the most critical degradation pathways. A Pareto-based classification is then applied to rank failure causes according to their contribution to system performance loss. The combined FMECA and Pareto approach makes it possible to highlight the dominant defects related to auxiliary components, flow regulation, sensor inaccuracies and the aging of the membrane and electrodes. Based on the critical causes identified, specific recommendations are proposed to improve reliability, including improved energy management and operating strategies, optimized control of pressure and humidity, and improved monitoring of auxiliary subsystems. The results provide a structured methodology for prioritizing degradation sources and guiding preventive maintenance and design improvements in fuel cell systems.

• Transport impedance with Current-modulated Hydrogen flow-rate Spectroscopy (CH2S). • Effective diffusivities and mass transport resistances of hydrogen measured with CH2S. • GDL substrate and MPL layers operando transport properties differentiated. • Transport properties compared for passive-PEMFC and conventional-PEMFC • Current density and active area effects on hydrogen transport in passive PEMFC. Current-modulated Hydrogen flow-rate Spectroscopy (CH2S) is the mass-transport impedance that relates cell current ( I ˜ ) and hydrogen flow rate ( Q ˜ H 2 ) in the anode of a proton exchange membrane fuel cell (PEMFC). The transfer function ( H = n F Q ˜ H 2 / I ˜ ) provides kinetic information about transport processes in the anode of a PEMFC under working conditions. CH2S can differentiate hydrogen transport in the gas diffusion layer substrate (GDLS) and in the microporous layer (MPL) of the anode. Using an analytical model and the distribution of relaxation times formalism, the effective, operando , hydrogen diffusivities and mass transport resistances of the GDLS and MPL are obtained. Here CH2S is used to study mass transport in a PEMFC anode fed with quasi-static hydrogen and air atmospheres, or passive PEMFC (p-PEMFC). The anode is a commercial gas diffusion electrode, with Pt/C based catalyst layer, a hydrophobic carbon black MPL, and a woven carbon cloth GDLS. The results show larger mass transport losses in the GDLS of the p-PEMFC compared with a convective PEMFC (c-PEMFC) fed with gases under forced convection. The MPL, however, presents same mass transport losses in both cell types, with operando water saturation close to 100%. Increasing current density, up to 180 mA cm -2 , has little impact on GDLS transport properties but improves them in the MPL attributed to thermal activation and drier conditions in the anode by water electroosmotic dragging. Larger active area size increases transport losses in p-PEMFC due to more difficult passive elimination of water from the cell by natural forces. Changes in the p-PEMFC design are proposed to mitigate mass transport losses and bring its efficiency closer to the c-PEMFC.

This study introduces a novel hybrid flow field configuration, termed “ser-pin”, developed to enhance the performance of proton exchange membrane fuel cells (PEMFCs) by integrating serpentine and pin-type geometries. The proposed design was numerically investigated using a single-cell PEMFC model through CFD simulations in ANSYS Fluent. A widely adopted triple-serpentine configuration was used as a benchmark to evaluate the electrochemical and fluidic performance of the hybrid structure. Comparative analyses were conducted under seven operating scenarios that included variations in cell temperature (50–70 °C), relative humidity (25–100%), and pressure (1–2 atm). Key performance parameters such as current density, power density, reactant and water distributions, temperature profiles, pressure drop, and reaction heat source behavior were comprehensively examined. The results consistently demonstrated that the ser-pin design outperformed the conventional layout in all tested conditions. At 0.3 V, the hybrid configuration achieved peak current densities of up to 1.27 A/cm 2 , while the maximum power density of 0.49 W/cm 2 was attained at 0.5 V, indicating improvements of approximately 6–8% over the reference design. The pin-type region significantly contributed to better reactant mixing, thermal homogeneity, and reduced local flooding or dehydration. Despite a higher pressure drop due to added geometric complexity, the overall performance gain proved substantial. These findings suggest that hybrid architectures with spatially functional features can address the limitations of traditional single-pattern designs and offer promising potential for next-generation PEMFC systems.

Coupled channel–electrode design for water transport and performance stability in proton exchange membrane fuel cells

The development of highly efficient and durable electrocatalysts for the oxygen reduction reaction (ORR) is critical for advancing proton exchange membrane fuel cells (PEMFCs) technology. Herein, a novel CoPc-S-COF/CNT hybrid was fabricated by integrating a robust 2D dithiine-linked phthalocyaninato cobalt (CoPc)-based covalent organic framework (CoPc-S-COF) on carbon nanotubes (CNTs) as a superior ORR electrocatalyst. The CoPc-S-COF was synthesized from hexadecafluorophthalocyaninato cobalt and 1,2,4,5-benzenetetrathiol to ensure robust conjugation. The in situ growth on functionalized CNTs was specifically tailored to boost electrical conductivity and stability. The resulting CoPc-S-COF/CNT hybrid exhibits exceptional acidic ORR activity with a half-wave potential of 0.79V vs. reversible hydrogen electrode, a limiting current density of 6.12mA cm-2 and remarkable long-term stability (8mV decay after 5000 cycles), comparable to commercial Pt/C. When implemented in a practical PEMFC, the CoPc-S-COF/CNT cathode achieves a peak power density of 1153.9mW cm-2 at 200kPa H2/O2 condition, outperforming most reported non-precious metal catalysts. In situ Fourier-transform infrared spectroscopy together with density functional theory calculations reveals that the dithiine bridge optimizes the electronic structure of Co-N4 active sites, lowering the energy barrier for *OOH intermediate formation. This work offers new insights into designing COF/CNT hybrids for high-performance energy conversion devices.

Data-driven optimization of hybrid membrane electrode assembly configurations for enhanced proton exchange membrane fuel cell performance

Degradation of the cathode catalyst layer (CCL) limits the durability of polymer electrolyte membrane fuel cells (PEMFCs) by reducing the electrochemically active surface area and impairing oxygen transport. These co-occurring effects are difficult to disentangle with standard electrochemical diagnostics. In this study, we used impedance-based analysis to quantify the individual contributions of catalyst and carbon support degradation in PEMFCs subjected to accelerated stress tests (ASTs): low-potential cycling (0.6–0.95 V, 55 000 cycles) and high-potential cycling (1.0–1.5 V, 50 000 cycles). In-operando electrochemical impedance spectroscopy under H 2 /air and impedance data analysis using the distribution of relaxation times and transmission line modeling were combined with complementary diagnostic techniques. This approach separated the ohmic, charge transfer, CCL ionomer, and mass transport resistances and tracked their evolution during ASTs. Low-potential cycling increased the charge transfer resistance by 29–56%, consistent with a loss of active surface area. High-potential cycling resulted in increased charge transfer, mass transport, and ohmic resistances, with a 77% reduction in CCL thickness, indicating severe carbon corrosion and collapse of the CCL structure. The resulting framework provides a practical tool to screen cathode materials and operating strategies by quantitatively linking specific degradation modes to electrochemical loss processes. • In-operando EIS with DRT separates kinetic, ionomer, and mass transport losses. • TLM quantifies charge transfer, ionomer and mass transport resistances during ASTs. • Low-potential cycling primarily raises kinetic losses consistent with ECSA loss. • High-potential cycling raises kinetic/transport losses due to structural degradation. • Ex-situ diagnostics validate impedance-derived resistance evolution and mechanisms.

A data-driven approach for multi-dimensional prediction of PEMFC performance using artificial neural networks

ABSTRACT Accurate prediction of the remaining useful life of proton exchange membrane fuel cell (PEMFC) is crucial for optimizing efficiency in energy systems. However, the complex and dynamic degradation behavior remains a significant challenge for lifespan prediction. To address this issue, a Parallel Interactive Encoder Network (PIE-NET) is proposed, representing a paradigm shift from conventional sequential architectures. The proposed framework is rigorously validated on both laboratory and real-world vehicular datasets, achieving a significant improvement in prediction accuracy. The root mean square errors under static and quasi-dynamic conditions are 0.00097 and 0.0032, representing a reduction of 33.7% and 11.1%, respectively, compared to other state-of-the-art algorithms. The relative errors of remaining useful life prediction are kept within 1%. This work provides a solid foundation for transitioning fuel cell lifetime prediction from laboratory research to in-vehicle engineering applications. Highlights A Parallel Interactive Encoder Network is proposed for aging prediction. A paradigm shift from serial to parallel-interactive architecture for temporal degradation modeling. Rigorous validation using both lab-scale data and in-vehicular data is conducted. The relative error of 0.95% is achieved in the prediction of remaining useful life.

ABSTRACT The proton exchange membrane fuel cell (PEMFC) converts clean hydrogen's chemical energy into electricity and is vital for carbon neutrality. However, its development is limited by low volumetric power density and high cost. Thickness‐reduced composite bipolar plates (CBPs) offer a promising solution to boost power density and reduce costs. CBPs are critical PEMFC components, comprising 70%–80% of the stack's volume and weight, and function for current collection, gas separation, and mechanical support. On this basis, this review explores strategies to achieve thickness reduction in CBPs from the perspectives of material, structure, and manufacturing processes, analyzes the primary factors influencing CBP thickness and key performance metrics starting from the theoretical minimum thickness limitation, and proposes enhancement approaches to improve the electrical conductivity, mechanical properties, and gas barrier properties of CBP following thickness reduction. The conductivity is improved by optimizing carrier transport, and the influence of material interface modification on gas permeability is analyzed. The design innovation of novel biomimetic structures optimizes the mechanical properties. By synthesizing these perspectives, this review offers valuable insights for reducing thickness and optimizing the performance of CBPs.