Hydrogen-fueled proton exchange membrane fuel cells are ideal power sources for transmedium equipment and need stable operation under two cathode oxidant conditions of air and pure oxygen with distinct mass transfer characteristics. This work experimentally investigated the performance and electrochemical impedance spectroscopy of the fuel cells with channel depths from 0.3 to 0.6 mm under air and pure oxygen cathode atmospheres, and developed a three-dimensional two-phase numerical model to clarify the internal mass transfer and liquid water distribution mechanisms. Results show that increased channel depth elevates mass transfer impedance and degrades cell performance: the 0.6 mm channel depth leads to a 33.6% drop in peak power density under air and a 19.03% drop under pure oxygen, compared with 0.3 mm. Reducing channel depth facilitates liquid water removal in air-fed cells but causes severe liquid water accumulation at the cathode channel outlet in pure oxygen-fed cells. This study reveals the coupling effects of channel depth and cathode oxidant, providing experimental and theoretical support for optimal flow field design of transmedium fuel cells.

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) have garnered considerable interest owing to their superior tolerance toward CO impurities and the inherent advantages of facile water management. However, severe phosphoric acid poisoning of Pt catalysts necessitates markedly higher Pt loadings than in low-temperature proton exchange membrane fuel cells, thereby constraining their large-scale deployment. Herein, we present an additive-assisted impregnation approach to synthesize ultrafine PtCo alloy nanoparticles encapsulated by defect-rich S-doped carbon encapsulation layers (CELs). The use of short-chain sodium thioglycolate enables the formation of ultrafine PtCo nanoparticles (-2.82 nm) coated with-0.4 nm-thick CELs, effectively suppressing metal sintering during high-temperature annealing and strengthening metal-support interactions. The S-doped CELs provide dual protection against phosphoric acid poisoning by physically isolating the PtCo alloys and introducing negatively charged carbon defects to electrostatically repel phosphate anions. Consequently, the optimized sodium thioglycolate-PtCo alloy electrocatalyst delivers a high mass activity of 0.695 A mgPt-1 at 0.85 V along with enhanced durability in 0.1 M H3PO4 at 80 degrees C. It further maintains excellent phosphate tolerance and oxygen reduction reaction activity, even in concentrated 85 wt% H3PO4 at 120 degrees C. Remarkably, in HT-PEMFCs, it achieves superior peak power densities of 613 and 908 mW cm-2 in H2-air and H2-O2, respectively, with a low Pt loading of 0.3 mgPt cm-2. Even at an ultra-low Pt loading of 0.1 mgPt cm-2, it delivers a peak power density of 355 mW cm-2 and an exceptional Pt-specific power density of 3.53 kW gPt-1 in H2-air cell, while sustaining stable operation over 100 h with minimal voltage decay. This study offers a versatile strategy to develop phosphate-resistant catalysts for high-performance HT-PEMFCs with low-Pt-loading.

This paper proposes an energy management frame work for fuel cell hybrid electric buses (FCHEBs). To leverage the complementary characteristics of fuel cells (FCs) and supercapacitors (SCs), a hybrid energy storage system (HESS) incorporating them is considered. The proposed framework is referred to as ACMPC-ADRC because it is a model predictive control (MPC) scheme combined with an adaptive compensation (AC) block and a modified active disturbance rejection control (ADRC) block. The AC block is composed of two parts: error compensation and adaptive weights. The former utilizes a linear function to compensate for the errors due to the linearization of the nonlinear HESS. The latter develops a multi-layer perceptron (MLP)-based method to determine the adaptive weights associated with the state variables in a real-time fashion. As for the modified ADRC block, a trajectory prediction part is introduced to generate a continuous predicted trajectory to more effectively reject the HESS disturbances. Extensive experiments are conducted using a hardware setup. The experimental results demonstrate the effectiveness of the proposed framework in properly splitting the load power and assigning the low-frequency and high-frequency components to the FC and the SC, respectively. Moreover, the proposed framework leads to a smaller change in the SC state of charge (SOC) after a drive cycle, a lower FC current change rate, and a lower equivalent hydrogen consumption for the HESS, which ultimately help lower the SC overcharging/overdischarging risks and boost the system economy.

The start-up performance of proton exchange membrane fuel cells in low-temperature environments directly affects their service life and market promotion prospects. However, it is still challenging to fully understand how different operating parameters synergistically intensify the cold startup efficiency of proton exchange membrane fuel cells. In this study, the cold-start performance of proton exchange membrane fuel cells is optimized via cathode catalytic H2-O2 reaction heating, integrated with machine learning for key indicator prediction and multi-objective optimization for operating parameter screening. The proposed strategy achieves a temperature rise exceeding 30 °C without external load at −20 °C, suppressing the peak ice volume fraction in the cathode catalyst layer to 3.28 vol

The growing global demand for clean and sustainable energy has driven rapid advancements in fuel cell technology. However, trace impurities in hydrogen fuel, such as carbon monoxide (CO), can significantly deactivate the anode by blocking its active sites, leading to performance degradation. Consequently, developing CO-tolerant electrocatalysts has become a critical priority. To address this, PtMo/C nanoalloy particles were synthesized by incorporating Mo atoms into Pt nanoparticles, demonstrating exceptional hydrogen oxidation reaction (HOR) performance in proton exchange membrane fuel cells (PEMFCs). Furthermore, MoOx-PtMo/C, with a MoOx-modified surface, exhibited superior CO tolerance. In situ CO adsorption surface-enhanced infrared absorption spectroscopy (SEIRAS) and density functional theory (DFT) calculations revealed that the synergistic effect of dual-stage electronic modulation from MoOx and Mo atoms adjusts the electronic structure of Pt, substantially weakening CO adsorption energy and enhancing CO tolerance. Remarkably, the optimized MoOx-PtMo-5 h/C achieved mass and specific activities of 2.86 A mgPt -1 and 2.80 mA cmECSA -2 at 50 mV, 3.8-fold and 3.0-fold higher than commercial Pt/C, respectively. Additionally, MoOx-PtMo-5 h/C demonstrated exceptional CO resistance in both three-electrode and PEMFC tests.

The distinctive superhydrophobic micro-nano structure and vein-like channel morphology of Tuscan kale leaves enable efficient control and self-cleaning of water droplets under low external forces in nature. This mechanism closely aligns with the gas–liquid two-phase transport and water removal requirements in proton exchange membrane fuel cells (PEMFCs). Based on Tuscan kale leaves, this study proposes Tuscan kale-inspired biomimetic flow field (TBFF) for PEMFCs. The design incorporates a tapering main channel, inter-branch channels, and bio-inspired surface grooves to boost reactant distribution and water removal efficiency. A validated numerical PEMFC model is established to assess how the amount of inter-branch channels affects the performance of the PEMFC. The calculation results indicate that a moderate count of branches enhances oxygen delivery and alleviates water accumulation, leading to improved current density uniformity and reduced local mass transport losses. Notably, the TBFF-2 configuration achieves the highest peak power density of 0.6776 W/cm2, outperforming conventional parallel and serpentine flow fields by 11.04 % and 4.86 %, respectively. TBFFs also reduce parasitic power and promote more uniform thermal distribution. These findings demonstrate the potential of biologically inspired flow field designs to improve PEMFC efficiency.

Proton Exchange Membrane Fuel Cells (PEMFCs) are widely regarded as a leading technology for sustainable energy conversion due to their high efficiency, compact structure, and zero-emission characteristics. However, the long-term performance and reliability of PEMFC stacks are often limited by internal inconsistencies, especially voltage nonuniformity among individual cells. This spatial variation in cell voltage reflects underlying degradation phenomena such as membrane dehydration, localized flooding, and catalyst deterioration, which can accelerate aging and lead to early failure. Although voltage uniformity is critical for system stability, it has not been sufficiently quantified under realistic operating conditions, restricting its application in predictive diagnostics. In this study, we propose a quantitative framework to assess voltage nonuniformity in a 350 cm2, 20cell PEMFC stack under varying current loads. We define four statistical measures: the coefficient of variation (CV), range ratio, skewness, and kurtosis. These indicators are used to describe the scale and shape of voltage dispersion and are further normalized and combined into a single Voltage Nonuniformity Index (VNI) to enable integrated evaluation. The results show that nonuniformity increases with current density, especially beyond the mid-load range where voltage distributions become more asymmetric and peaked. These patterns highlight the responsiveness of the proposed indicators to electrochemical imbalance and temperature gradients under dynamic operation. By combining several statistical features into a single evaluation scheme, the framework provides a multidimensional view of intra-stack behavior. This enhances the ability to detect early-stage degradation and supports real-time monitoring and control. This study contributes to a better understanding of voltage distribution patterns in PEMFC systems and offers practical guidance for improving stack design, operating strategies, and health management.

During the operation of proton exchange membrane fuel cells (PEMFCs), particularly under low-temperature cold-start conditions, the freezing of liquid water within the gas diffusion layer (GDL) can significantly impair both the performance and structural stability of the cell. Therefore, effective water management strategies are essential. This study combines high-fidelity numerical simulations and in situ cryo-microscopy to systematically investigate the impact of carbon fiber structure on the dynamic transport characteristics of liquid water on the GDL surface. Additionally, the influence of GDL surface wettability and carbon fiber structure on the freezing behavior of liquid water is explored. The results show that by adjusting fiber spacing and surface wettability, it is possible to control the diffusion behavior of liquid water within the GDL and reduce the risk of flooding. Hydrophilic GDLs promote a uniform water distribution throughout the pore structure and facilitate a continuous freezing process. In contrast, hydrophobic GDLs result in discrete droplet freezing and abrupt pore blockage. The hydrophobic GDL reaches a peak ice coverage of 18% at −15 °C, while the hydrophilic GDL shows a sharper increase, reaching 26% at −30 °C after steadily increasing to −20 °C. These differences are attributed to variations in surface wettability and fiber-scale wetting interactions between the two materials. The findings emphasize the critical role of wettability in directing ice growth pathways and maintaining the structural integrity of the GDL. This study offers valuable theoretical insights for optimizing GDL design and provides experimental evidence for improving the cold-start performance of PEMFCs.

Polytetrafluoroethylene (PTFE) is the most widely used catalyst layer (CL) binder in a polybenzimidazole phosphoric acid (PBI-PA)-based high-temperature proton exchange membrane fuel cell (HT-PEMFC) due to its great hydrophobicity. However, PTFE also limits the formation of an effective triple-phase boundary (TPB) due to its strong resistance to acid retention. To obtain the composite ionomer in the CL of HT-PEMFC, polybenzimidazole (PBI) is thus invited. Then, an in situ quaternization strategy on PBI is developed to increase the TPB concentration in CL by controlling the PA distribution and taking into account the superior PA retention capability of quaternary ammonium groups. At the same time, Pt active sites can be freed and mass transfer channels can be in situ constructed. Consequently, the corresponding HT-PEMFC fed with H2/O2 attains a maximum power density of 755 mW/cm2 and an electrochemical surface area of 35.56 cm2/mgPt, surpassing those equipped with PTFE by 10 and 30%, respectively. The electrochemical performance improvement indicates that the in-situ quaternization strategy on the ionomer has great application potential in practical HT-PEMFC manufacturing.

Achieving high activity and CO* tolerance in formic acid oxidation reaction remains a long-standing challenge due to the strong binding of CO intermediates on Pt-based catalysts. Here, we present a medium-entropy PtBi1.5PbMn0.5Ni0.5 catalyst featuring a hexagonal nanoplate morphology and homogeneous elemental distribution, synthesized via a surfactant-directed liquid-phase reduction route. The introduction of multi-elemental dopants reshapes the Pt d-band center and stabilizes the Pt-Pt and Pt-M bonding, thereby suppressing CO* adsorption and promoting the direct dehydrogenation pathway. In situ FTIR spectroscopy confirms the negligible accumulation of CO* intermediates, while CO stripping and DFT calculations reveal lowered CO binding energy and enhanced electronic coupling. As a result, the catalyst exhibits a record-high mass activity of 3.1 A.mgPt-1 and excellent operational stability over 18,000 s. This work demonstrates the potential of entropy-stabilized Pt-based alloys in overcoming activity-poisoning trade-offs, offering a rational design framework for next-generation DFAFC electrocatalysts.

The gradual depletion of fossil energy sources and the excessive emission of greenhouse gases have significantly contributed to global warming, profoundly impacting the natural environment. Proton exchange membrane fuel cells (PEMFCs), specifically hydrogen (H-2) fuel cells, offer a promising solution by converting chemical energy directly into electrical energy through electrochemical reactions. PEMFCs boast numerous advantages, including zero emissions, high power density, rapid response times, and a simple structure, effectively mitigating the effects of the energy crisis and environmental degradation. Based on their operating temperatures, PEMFCs are categorized into low-temperature PEMFCs (LT-PEMFCs) and high-temperature PEMFCs (HT-PEMFCs). In LT-PEMFCs, operating at lower temperatures in the presence of water, water serves as the proton transport medium. Conversely, in HT-PEMFCs, proton conductivity relies on a different mechanism. Nafion, which is highly dependent on a hydrated condition, exhibits a dramatic drop in conductivity when the operating temperature exceeds 100 degrees C. Polybenzimidazole (PBI) membranes, known for their excellent thermal and chemical stability, have garnered significant attention for high-temperature PEM applications, providing better proton conductivity under anhydrous conditions. However, large-scale hydrogen production technologies often fail to meet purity requirements due to high associated costs, with less than 5% of the globally produced H-2 coming from electrolytic water. For instance, most available H-2 is derived from methane steam reforming, introducing gaseous impurities such as carbon monoxide (CO), sulfuretted hydrogen (H2S), and ammonia (NH3) when used as fuel. These impurities can significantly degrade the performance of the electrode catalyst. The presence of trace amounts of CO in H-2 fuel poisons the catalyst during the reaction process. When reformate H-2 is supplied in a PEMFC, these concentrations CO can cause CO-poisoning and activity degradation. For the commercial Pt anodes, it is noted that the acknowledged maximum CO poisoning limits are 10 and 100 ppm, respectively. A typical method for overcoming CO poisoning is the further purification of the hydrogen fuel after the reforming process, which can minimize the CO concentration. However, even for the CO concentration limits to 0.2 ppm, the efficiency of PEMFCs is considerably reduced. Furthermore, the purification cycles required to achieve such low CO concentrations prohibitively increase the costs. Additionally, the release of phosphoric acid (PA) during HT-PEMFC operation can lead to phosphoric acid poisoning, reducing catalyst activity. The catalysts used in PEMFCs, primarily based on precious metals like platinum (Pt), exhibit superior electrocatalytic properties but are susceptible to toxicity and have limited stability. Pt, with its unique d-band structure of 5d electron orbitals, is the most efficient electrocatalysts for PEMFCs. The hydrogen oxidation reaction (HOR) rate on Pt-based nanoparticles is very fast, allowing the Pt load of the anode catalyst to be as low as 0.05 mg cm(-2). However, the oxygen reduction reaction (ORR) at the cathode is about five orders of magnitude slower than the HOR at the anode, requiring a higher Pt load (similar to 0.4 mg cm(-2)) to maintain performance. While Pt-based catalysts are highly efficient for the HOR at the anode, their significantly slower kinetics during the ORR at the cathode require increased Pt loadings. This discrepancy contributes to reduced catalyst stability and higher costs, thereby hindering widespread commercial adoption. Therefore, it is imperative to design and improve Pt-based catalysts to enhance the utilization rate and anti-poisoning ability of Pt. This paper reviews the current application status of Pt-based catalysts. It begins by describing the toxicity challenges faced by PEMFCs, focusing on the design of Pt-based catalysts to improve anti-toxicity. Finally, the development direction of Pt-based catalysts in PEMFCs is discussed and prospected.

This study investigates the effects of exhaust gas recirculation (EGR) on ammonia-diesel dual-fuel combustion through optical experiments in a constant volume chamber, varying ambient temperatures (700 K-800 K) and oxygen concentrations (11%-21 %). The results reveal that the combustion process can be divided into three stages based on flame characteristics: diesel premixed combustion, diesel diffusion combustion, and ammonia premixed combustion. As the ambient temperature and oxygen concentration decrease, the luminescence region of the NH2 group narrows, and its luminescence intensity diminishes, indicating lower NO emissions. Compared to the decrease in oxygen concentration from 16 % to 11 %, the reduction from 21 % to 16 % has a less pronounced impact on ammonia-diesel combustion performance. The peak heat release rate (HRR) shows a non- monotonic trend, initially increasing and then decreasing as the temperature drops. Ammonia-diesel combustion deteriorates at extremely low ambient temperatures and oxygen concentrations, exhibiting a double-peak HRR. These findings suggest that mild EGR can be applied to real ammonia-diesel engines to effectively reduce NO emissions, although it may slightly compromise combustion performance.

High-intensity vibration conditions may adversely affect water transport within proton exchange membrane fuel cells. Optimization of structural parameters as an effective approach to improve water transport inside gas diffusion layers. In this study, the impact of various structural characteristics of the gas diffusion layers on water transport under high-intensity vibration conditions is presented for the first time, the optimal combination of structural properties for these conditions is proposed. The results indicate that vibration exacerbates the localized agglomeration of liquid water within the gas diffusion layer, which leads to impeded gas transport and, consequently, reduced cell performance. The high hydrophobicity and large pore size structure, although promoting water transport, further exacerbated the substantial increase in water content under vibration conditions, reaching up to 103 %. A combination of moderate porosity, moderate hydrophobicity, and minimal thickness represents the optimal structural characteristics for mitigating the effects of vibration and ensuring efficient water transport.

This paper proposes an optimization framework to address the component sizing and energy management problems in an electric-hydrogen hybrid energy storage system connected to a wind turbine. The total cost of the hybrid system is minimized using a particle swarm optimization (PSO) algorithm. In particular, four decision variables are optimized: the electrolyzer (EL) size, the supercapacitor (SC) size, and two parameters in the energy management strategy (EMS). To determine the power split factor for the wind power, the EMS introduces an artificial potential field (APF) and defines a virtual force based on the SC state of charge (SOC). Two APF parameters are optimized to tune the power allocation between the EL and the SC: the shaping parameter of the virtual force and the basis parameter of the power split factor. Since the cutoff frequency of the low pass filter (LPF) in the EMS is adaptively updated based on the optimized APF parameters, the proposed framework is referred to as the “OP-APF” framework. The effectiveness of the OP-APF framework is validated by performing MATLAB and real-time simulations. Compared to three baseline frameworks, OP-APF is more effective in reducing the system total cost, controlling the SC SOC, and alleviating the EL degradation.

To enhance the mechanical properties, proton conductivity, and oxidative stability of phosphoric acid (PA)doped polybenzimidazoles (PBIs) for application as high-temperature proton exchange membranes (HT-PEMs), we design a ternary blocked copolymer structure of PBIs (Tbc-PBIs). A series of segmented structures comprising repeat units of F6PBI, OPBI and m-PBI are synthesized via the PPA method with varied molar ratios while maintaining similar molecular weights in this study. Ex-situ properties of Tbc-PBIs are thoroughly characterized and in-situ fuel cell tests are conducted. The results demonstrate substantial improvements in proton conductivity (142.8 mS cm-1 at 160 degrees C), mechanical strength (12.14 MPa with 386 % PA doping) and oxidation stability. Furthermore, the fuel cell performance of Tbc-PBIs exhibits significant enhancements compared to commercial PBI membranes, achieving an excellent power density of 704.0 mW cm-2 at 160 degrees C.

As global demand for clean and sustainable energy continues to rise, fuel cell technology has seen rapid advancement. However, the presence of trace impurities like carbon monoxide (CO) and hydrogen sulfide (H₂S) in hydrogen fuel can significantly deactivate the anode by blocking its active sites, leading to reduced performance. Developing electrocatalysts that are resistant to CO and H₂S poisoning has therefore become a critical priority. This paper provides a comprehensive analysis of the poisoning mechanisms of CO and H₂S and reviews the key strategies developed over the past few decades to enhance the impurity tolerance of anode electrocatalysts. It begins by examining the differences in hydrogen oxidation reaction (HOR) mechanisms in acidic and alkaline environments, focusing on the roles of hydrogen binding energy (HBE) and hydroxide binding energy (OHBE). Next, it outlines three main approaches to mitigate CO poisoning: (I) bifunctional mechanisms, (II) direct mechanisms, and (III) constructing protective blocking layers. The review then shifts to strategies for countering H₂S poisoning, emphasizing both electrocatalyst design and structural improvements in fuel cells. Finally, the paper highlights recent advances in anti-poisoning electrocatalysts, discusses their applications and limitations, and identifies the key challenges and future opportunities for further research in this field.

In this work, a cascade PEMFC system for enhancing coalbed methane recovery is proposed. Conventional and advanced exergy, exergoeconomic, and exergoenvironmental analyses are performed to determine the irreversibility and identify potential improvements for each component. Use of monoethanolamine solution to absorb the large amount of carbon dioxide produced during the reaction. At the same time, the carbon tax is considered in the exergoeconomic analysis. Multi-objective optimization visualizes the distribution of noninferior solutions through Pareto front and uses TOPSIS and Shannon entropy methods to determine the optimal solution. The result indicates that the exergy destruction, exergoeconomic and exergoenvironmental impact rates of the system are 298.0251 kW, 27.8790$/h, and 424.3612mpts/h, respectively. The results of the advanced exergy destruction, exergoeconomic and exergoenvironmental show that the cathode has the highest avoidable exergy destruction and exergoeconomic cost rate (51.1256 kW and 2.5326$/h), respectively. The heat exchanger 2 has the highest avoidable exergoenvironmental impact rates, which is 58.5541 mpts/h. The three parameters of the total exergy destruction, the total exergoeconomic cost rate, and the exergoenvironmental impact rates are selected for the multi-objective optimization, and it is found that the system is optimal at a reforming temperature of 822.39 degrees C. This research provides a clearer direction for optimizing this novel coupled system.

This paper proposes a real-time energy management strategy (EMS) for fuel cell hybrid electric trucks (FCHETs). In such trucks, hydrogen fuel cells (FCs) are employed as the primary power source while lithium-ion batteries can be used as the energy buffer. Since hydrogen is still expensive and the FC technology readiness level (TRL) is still low, properly-designed EMSs are effective approaches for boosting the fuel economy FCHETs. Therefore, an EMS is proposed in this paper to determine the optimal power allocation between the FC and the battery in FCHETs. The EMS is composed of three blocks: alternating direction method multipliers (ADMM), rolling optimization, and speed prediction. The EMS is implemented on the basis a prediction horizon. For a particular horizon, the speed prediction block predicts the FCHET speed using a long short-term memory (LSTM) network. Based on the predicted speed, the electric machine power determined, which is further split and allocated to the FC and the battery using the ADMM algorithm. The effectiveness of the EMS is demonstrated by performing real-time simulations using a real-time system based on a dSPACE DS1202 platform. Simulation results show that the EMS can effectively split and allocate the load power to minimize the hydrogen cost and balance the battery energy by reducing the hydrogen consumption and maintaining the battery state of charge (SOC), respectively. Moreover, the EMS is evaluated against CVX-based framework. Evaluation results show that compared to the CVX-based framework, the EMS leads 5.94% and 14.31% lower hydrogen costs as well as 85.58% and 95.66% lower battery SOC changes for the modified CYC_WVUCITY and CYC_NYCTRUCK drive cycles, respectively.