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The significant role of the cathodic binder in modulating mass transport within the catalyst layer (CL) of fuel cells is essential for optimizing cell performance. This investigation focuses on enhancing the membrane electrode assembly (MEA) through the utilization of a short-side-chain perfluoro-sulfonic acid (SSC-PFSA) ionomer as the cathode binder, referred to as SSC-MEA. This study meticulously visualizes the distinctive interpenetrating networks of ionomers and catalysts, and explicitly clarifies the triple-phase interface, unveiling the transport-friendly microstructure and transport mechanisms inherent in SSC-MEA. The SSC-MEA exhibits advantageous microstructural features, including a better-connected ionomer network and well-organized hierarchical porous structure, culminating in superior mass transfer properties. Relative to the MEA bonded by long-side-chain perfluoro-sulfonic acid (LSC-PFSA) ionomer, noted as LSC-MEA, SSC-MEA exhibits a notable peak power density (1.23 W cm-2), efficient O2 transport, and remarkable proton conductivity (65% improvement) at 65 °C and 70% relativity humidity (RH). These findings establish crucial insights into the intricate morphology-transport-performance relationship in the CL, thereby providing strategic guidance for developing highly efficient MEA.

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.

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

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]

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]

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

Influence of structure and microstructure on the dielectric properties of single-phase solid solution of ZrO2–CeO2 system with 80% CeO2 has been investigated. Highly dense polycrystalline Ce0.8Zr0.2O2 ceramic was synthesized through solid-state reaction route, and its cubic structure was verified through X-ray diffraction and Raman spectroscopy techniques. The compact grain morphology was validated through FESEM with grain size of ~9 μm. Dielectric properties of the Ce0.8Zr0.2O2 were probed by applying ac electric field of different frequencies at variable temperatures. The measured dielectric constant of Ce0.8Zr0.2O2 in the presence of applied ac field of 2 kHz frequency at 300 K is ~1819, is reduced to 27 with an increase in the frequency up to 2 MHz, which is a comparatively high dielectric constant than binary oxides. The high packing fraction of cubic structure of ZrO2–CeO2 with 80% CeO2 showed a small dielectric loss ( tan δ ). The interfacial polarization effect was confirmed by low-frequency dielectric dispersion in ε ′ ′ and ε r . The large conductivity coupled with a relaxation phenomenon at higher temperatures is attributed to the shift from extended hopping to localized ionic transport. Ce0.8Zr0.2O2 showed a negative coefficient of resistance validated through increasing ac conductivity with temperature. A high dielectric constant with small dielectric tangent loss achieved in cubic structured sample established its application in high-performance metal oxide semiconductor field effect transistor (MOSFET) devices along with the formation of advanced solid-electrolytes for solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Influence of structure and microstructure on the dielectric properties of single-phase solid solution of ZrO2–CeO2 system with 80% CeO2 has been investigated. Highly dense polycrystalline Ce0.8Zr0.2O2 ceramic was synthesized through solid-state reaction route, and its cubic structure was verified through X-ray diffraction and Raman spectroscopy techniques. The compact grain morphology was validated through FESEM with grain size of ~9 μm. Dielectric properties of the Ce0.8Zr0.2O2 were probed by applying ac electric field of different frequencies at variable temperatures. The measured dielectric constant of Ce0.8Zr0.2O2 in the presence of applied ac field of 2 kHz frequency at 300 K is ~1819, is reduced to 27 with an increase in the frequency up to 2 MHz, which is a comparatively high dielectric constant than binary oxides. The high packing fraction of cubic structure of ZrO2–CeO2 with 80% CeO2 showed a small dielectric loss ( tan δ ). The interfacial polarization effect was confirmed by low-frequency dielectric dispersion in ε ′ ′ and ε r . The large conductivity coupled with a relaxation phenomenon at higher temperatures is attributed to the shift from extended hopping to localized ionic transport. Ce0.8Zr0.2O2 showed a negative coefficient of resistance validated through increasing ac conductivity with temperature. A high dielectric constant with small dielectric tangent loss achieved in cubic structured sample established its application in high-performance metal oxide semiconductor field effect transistor (MOSFET) devices along with the formation of advanced solid-electrolytes for solid oxide fuel cells. [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]

Solid oxide fuel cells (SOFCs) are an efficient, reliable and clean source of energy. Predictive modeling and analysis of their performance is becoming increasingly important, especially with the growing emphasis on sustainable development's requirements. However, mathematical modeling is difficult due to the complexity of its internal structure. In this study, the system's electricity generating performance and operational characteristics were analyzed using recent on-site monitoring data first. Then, based on Pearson's correlation coefficient, some of the variables were selected to build two prediction models: an artificial neural network (ANN) model and a multiple linear regression (MLR) model. The models were evaluated on the basis of the normalized mean square error (NRMSE), which was 1.89% for the MLR model and 0.66% for the ANN model, with no overall bias. They were also compared with other existing models, and it was found that the two models used in this study have the advantage of high accuracy and low difficulty. Therefore, the models developed in this study can more accurately and effectively assess the SOFC system's state and can better support work to improve the thermoelectric performance of SOFC systems. [ABSTRACT FROM AUTHOR]

Triblock copolymers such as styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) have been widely used as an anion exchange membrane for fuel cells due to their phase separation properties. However, modifying the polymer architecture for optimized membrane properties is still challenging. This research develops a strategy to control the membrane morphology based on quaternized SEBS (SEBS-Q) by dual-tapering the interfacial block sequences. The structural and transport properties of SEBS-Q with various tapering styles at different hydration levels are systematically investigated by coarse-grained molecular simulations. The results show that the introduction of the tapered regions induces the formation of a bicontinuous water domain and promotes the diffusivity of the mobile components. The interplay between the solvation of the quaternary groups and the tapered fraction determines the conformation of polymer chains among the hydrophobic–hydrophilic subdomains. The strategy presented here provides a new path to fabricating fuel cell membranes with controlled microstructures. [ABSTRACT FROM AUTHOR]

In this paper, a meticulous modeling approach is proposed not only for a fuel cell stack itself but also for all auxiliary components that collectively form the fuel cell system. This comprehensive modeling approach encompasses a wide range of components, including, but not limited to, the hydrogen recirculation pump and the air compressor. Each component is thoroughly analyzed and modeled based on the detailed specifications provided by suppliers. This involves considering factors such as efficiency, operating parameters, response times, and interactions with other system elements. By integrating these detailed models, a holistic understanding of the entire fuel cell system's performance can be attained. Such an approach enables engineers and designers to simulate various operating scenarios, predict system behavior under different conditions, and optimize the system design for maximum efficiency and reliability. Moreover, it allows for informed decision-making throughout the system's development, deployment, and operational phases, ultimately leading to more robust and effective energy systems. The model validation is performed by comparing experimental data to theoretical results, and the observed difference does not exceed 3%. [ABSTRACT FROM AUTHOR]

The use of polymer electrolyte membrane (PEM) fuel cells as an alternative to internal combustion engines can significantly contribute to the decarbonization of the transport sector, especially for heavy-duty applications. However, degradation is still an issue for this type of component, affecting their durability and performance. In this scenario, a detailed analysis of the anodic and cathodic distributors' flow-field geometry may help to identify some local stressors that trigger the degradation mechanism, such as local hot spots and reactants not having a uniform distribution. A computational fluid dynamic (CFD) methodology is able to provide a volumetric description of a PEM fuel cell so it can be a useful tool to better understand the physical phenomena that govern the component operations. In this work, the open-source simulation library openFuelCell2 is adopted for a detailed analysis of two different PEM fuel cells characterized by standard distributor geometries, namely a parallel channel geometry and a serpentine configuration. The library, based on the OpenFOAM code, has been extended with a novel implementation accounting for the catalytic activity reduction due to the platinum oxide (PtOx) formation occurring under certain particular conditions. The adopted methodology is firstly validated resorting to experimental data acquired for the two different fuel cell configurations. The analysis highlights that the PtOx formation leads to a reduction in the fuel cell performance reaching up to 60–80% when operating at high voltages. Then, the effect of the distributor geometries on the component performance is investigated by resorting to in-plane and through-plane physical quantity distribution, such as reactant concentration, pressure or velocity fields. While the parallel flow channel configuration shows some diffusion losses under the rib, the serpentine channel geometry configuration can achieve some local performance peaks thanks to the convective flow in the gas diffusion layer (GDL) driven by local pressure gradients. Furthermore, the local enhancement in terms of higher current density under the rib is associated with an effective heat removal due to the high thermal capacity of the bipolar plate, avoiding the generation of local hot spots. [ABSTRACT FROM AUTHOR]

The energy management system of a fuel cell electric robot should be highly responsive to provide the required power for various tactical operations, navigation of different routes, and acceleration. This paper presents a new multi-level online energy management strategy for a fuel cell electric robot based on the proposed functions of equivalent hydrogen fuel value evaluation, classification of the battery state of charge via the squared combined efficiency function, identification of the robot maneuver condition based on the proposed operation state of robot function, improvement of the overall energy efficiency based on the proposed function of the battery overcharge control, and separation of the functional points of the fuel cell based on the operational mode control strategy. The simulation study of the proposed online multi-level energy management strategy was carried out with MATLAB R2018b software to verify its superiority by comparing with other strategies. The results indicate a reduction in hydrogen consumption, reduction in fuel cell power fluctuations, prevention of battery overcharging, and incrementation in the total energy efficiency of energy storage systems compared to other energy management strategies. [ABSTRACT FROM AUTHOR]

This study investigates the influence of surface roughness on the performance of polymer electrolyte membrane fuel cells (PEMFCs) through computational simulations using COMSOL Multiphysics. Two distinct gas flow channel (GFC) models of serpentine and parallel GFC structures were analysed, featuring various surface roughness levels to examine their impact on gas pressure and velocity dynamics. Rough surfaces are modeled using trigonometric functions to replicate machining-induced variations. Finite element simulations were conducted, assessing the time-dependent relationship between gas pressure and velocity while considering different electrode phase potentials as a function of surface roughness. Rough surfaces generally enhance mass transport, water management, and current distribution compared to smooth surfaces. The results indicated that a surface roughness of approximately 1 µm optimizes PEMFC performance by balancing pressure and velocity, enhancing electrochemical reactions, and reducing excessive pressure drops within the cell. Notably, the 0.7 V operating voltage was found to be the most efficient, achieving rapid stabilization of pressure and velocity levels swiftly. The findings underscore the importance of precise control over GFC roughness to enhance PEMFC performance gains in commercial applications, especially when multiple cells are stacked to achieve high power outputs. [ABSTRACT FROM AUTHOR]

An ultra-high-speed electric air compressor (UHSEAC) generates a load torque component during operation, leading to unstable output. As air passes through the UHSEAC, the air density changes significantly, resulting in increased uneven distribution. This causes rapid changes in gas parameters, making them difficult to extract. Consequently, the behavior of load torque component variations under ultra-high-speed operating conditions (UHSOC) remains unclear. The influence of UHSOC on the load torque component has not been studied. In this article, the fluid model of the UHSEAC is established and verified, and the load torque component is extracted based on this model. The influence of speed and torque on the load torque component under UHSOC is then studied. The results show that the frequency of the load torque component increases by 14.29% as the speed increases from 70,000 rpm to 90,000 rpm. Additionally, as the torque increases from 1.3 Nm to 1.7 Nm, the amplitude of the load torque component increases by 69.56%. These findings provide valuable guidance for future scholars seeking to optimize UHSEAC design to reduce load torque components. [ABSTRACT FROM AUTHOR]

Flow fields are a primary component of polymer electrolyte membrane fuel cells (PEMFCs), the components supplying fuel cells with reactant gases, such as hydrogen and oxygen. However, the flow fields of fuel cells are limited by the nonuniform poor distribution of reactant gases, unintended pressure drop across channels, and poor water management, among other issues. Thus, relevant designs must focus on obtaining the lowest possible pressure drop while attaining the best possible distribution of reactant gases, further improving cell performance. In this work, the impact of novel bioinspired flow field designs on PEMFC performance was investigated. Three flow field configurations, namely, sunflower-inspired flow field (SUFF), flower of life-inspired flow field (FLFF), and palm frond-inspired flow field (PAFF), were designed, as inspired by the shape of the sunflower (i.e., flower of life and palm frond). Results revealed that the optimal operating conditions for the fuel cell were 1 L/min and 1.1 bar. The bioinspired configurations significantly affected PEMFC performance at a low voltage (< 0.645 V), but the impact was negligible at a high voltage (> 0.645 V). Furthermore, the ohmic loss region and the concentration loss region were both significantly improved by the bioinspired designs. The maximum power density was significantly increased for SUFF, FLFF, PAFF1, and PAFF2 by 16.84%, 6.07%, 6.32%, and 10.40%, respectively. [ABSTRACT FROM AUTHOR]

The unique properties of solid acid electrolytes, in particular CsH2PO4, are in many ways ideal for fuel cell operation. However, the technology is constrained by high cathode overpotentials. Here a simplified cathode geometry is employed to obtain the fundamental electrochemical parameters (exchange current density and charge transfer coefficient) describing the oxygen reduction reaction (ORR) at the CsH2PO4‐Pt‐gas interface. The parameters are incorporated into a 1D model of the voltage–current characteristics of realistic SAFC cathodes, which reproduced the measured polarization behavior of such cathodes without recourse to fitting adjustable parameters. Following this validation, the model is utilized to evaluate the impact of changes to cathode properties, microstructure, and operating conditions. Of these, the charge transfer coefficient, measured to have a value of ≈0.6 for ORR on Pt in the SAFC cathode environment, is found to have the greatest impact on power output. Nevertheless, even without material modifications, a combination of microstructural and operational modifications are identified with projected performance metrics meeting Department of Energy targets (0.8 V at 300 mA cm−2, and peak power density of 1 W cm−2), albeit at high Pt loadings. However, the analysis indicates that truly meaningful advances will likely necessitate the discovery of alternative ORR catalysts. [ABSTRACT FROM AUTHOR]

The growing concern about climate change and the contemporary increase in mobility requirements call for faster, cheaper, safer, and cleaner means of transportation. The retrofitting of fossil-fueled piston engine ultralight aerial vehicles to hydrogen power systems is an option recently proposed in this direction. The goal of this investigation is a comparative analysis of the environmental impact of conventional and hydrogen-based propulsive systems. As a case study, a hybrid electric configuration consisting of a fuel cell with a nominal power of about 30 kW, a 6 kWh LFP battery, and a pressurized hydrogen vessel is proposed to replace a piston prop configuration for an ultralight aerial vehicle. Both power systems are modeled with a backward approach that allows the efficiency of the main components to be evaluated based on the load and altitude at every moment of the flight with a time step of 1 s. A typical 90 min flight mission is considered for the comparative analysis, which is performed in terms of direct and indirect emissions of carbon dioxide, water, and pollutant substances. For the hydrogen-based configuration, two possible strategies are adopted for the use of the battery: charge sustaining and charge depleting. Moreover, the effect of the altitude on the parasitic power of the fuel cell compressor and, consequently, on the net efficiency of the fuel cell system is taken into account. The results showed that even if the use of hydrogen confines the direct environmental impact to the emission of water (in a similar quantity to the fossil fuel case), the indirect emissions associated with the production, transportation, and delivery of hydrogen and electricity compromise the desired achievement of pollutant-free propulsion in terms of equivalent emissions of CO2 and VOCs if hydrogen is obtained from natural gas reforming. However, in the case of green hydrogen from electrolysis with wind energy, the total (direct and indirect) emissions of CO2 can be reduced up to 1/5 of the fossil fuel case. The proposed configuration has the additional advantage of eliminating the problem of lead, which is used as an additive in the AVGAS 100LL. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Electrochemistry is the property of Journal of Electrochemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the development of lithium-ion batteries and fuel cells, the application of hybrid power systems is becoming more and more widespread. To better optimize the energy management problem of fuel cell hybrid systems, the accuracy of system modeling and simulation is very important. The hybrid system is formed by connecting the battery to the fuel cell through an active topology. Digital twin technology is applicable to the mapping of physical entities to each other with high interactivity and fast optimization iterations. In this paper, a relevant model based on mathematical logic is established by collecting actual operational data; subsequently, the accuracy of the model is verified by combining relevant operating conditions and simulating the model. Subsequently, a three-dimensional visualization model of a hybrid power system-based sightseeing vehicle and its operating environment was established using digital twin technology to improve the model simulation of the fuel cell hybrid power system. At low speeds, the simulation results of the hybrid power system-based sightseeing vehicle have a small error compared with the actual running state, and the accuracy of the data related to each internal subcomponent is high. In the simple interaction between the model display vehicle and the environment, the communication state can meet the basic requirements of the digital twin model because the amount of data to be transferred is small. This study makes a preliminary attempt at digital parallelism by combining mathematical logic with visualization models and can be used as a basis for the subsequent development of more mature digital twin models. [ABSTRACT FROM AUTHOR]

Objective Hydrogen energy becomes one of the solutions for energy transition in rail transit due to its characteristics such as abundant reserves, ecological friendliness, and efficient transition. At the initial stage of hydrogen energy application in rail transit vehicles, it is necessary to analyze the existing research status and put forward application suggestion. Method The application background and characteristics of hydrogen energy are described, and the application status of hydrogen energy in rail transit vehicles at home and abroad is introduced. On this basis, the key technical challenges of hydrogen energy application in the field of rail transit are extracted, and their research status is analyzed. Then, according to the application and research status, the urgent problems to be solved and overcome in the application of hydrogen energy in the field of rail transit are summarized, and relevant suggestions are put forward. Result & Conclusion Driven by both the application promotion and the technological innovation, hydrogen energy has a broad application prospect in the field of rail transit. The industrial policy, standard system and application technology should be continuously promoted for the further application of hydrogen energy in rail transit field, helping energy transition in rail transit.

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.

In this study, 3-iodo-2-(p-tolyl)benzo[b]thiophene (4C) is synthesized by using Sonagashira coupling reactions and electrophilic cyclization reactions. Electrochemical measurements have been performed using electrochemical methods such as cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) in the environment of 1 M KOH + 0.5M N2H4 solution. The CV results obtained showed that 4C catalyst promoted the generation of the best current (15.40 mA/cm2), and EIS results confirmed that electrode modifeed with the same derivative presented the lowest charge transfer resistance. Taken together, these results suggest that 4C organocatalyst could be used as an anode efficient catalyst in hydrazine (N2H4) fuel cells.

Abstract High-power converters with significant gains represent established configurations that hold appeal for applications in the industrial and commercial sectors, such as fuel cell electric vehicles (FCEV), energy backup systems, and automotive headlamps. Existing literature predominantly features topologies employing a single-duty ratio. However, this singular approach may not be dependable for operations with high-duty cycles, necessitating the incorporation of additional components to enhance voltage gain. To address this, the current study introduces the concept of time-sharing within the context of a high-gain non-isolated DC–DC converter. This innovative approach achieves substantially higher output voltage gains, approximately 13.33 times that of the input voltage. The analysis of the proposed converter is approached from various perspectives. Finally, it is examined within the MATLAB/Simulink environment, where the theoretical analysis is validated, and an efficiency of 97.4% is achieved.

Coordination environment engineering is developed to synthesize Fe SA /NSC catalysts with the tailored N, S co-coordinated Fe atomic site. [Display omitted] • The Fe-N 3 S active site with the optimized electronic structure is constructed. • S doping promotes the OH* desorption, thus leading to enhanced kinetics process. • The catalyst displays impressive ORR activity in both alkaline and acidic mediums. • The catalyst exhibits excellent performance in Zn-air batteries and fuel cells. Atomically dispersed iron–nitrogen-carbon (FesbndNsbndC) materials have been considered ideal catalysts for the oxygen reduction. Unfortunately, designing and adjusting the electronic structure of single-atom Fe sites to boost the kinetics and activity still faces grand challenges. In this work, the coordination environment engineering is developed to synthesize the Fe SA /NSC catalyst with the tailored N, S co-coordinated Fe atomic site (Fe-N 3 S site). The structural characterizations and theoretical calculations demonstrate that the incorporation of sulfur can optimize the charge distribution of Fe atoms to weaken the adsorption of OH* and facilitate the desorption of OH*, thus leading to enhanced kinetics process and intrinsic activity. As a result, the S-modified Fe SA /NSC exhibits outstanding catalytic activity with the half-wave potentials (E 1/2) of 0.915 V and 0.797 V, as well as good stability, in alkaline and acidic electrolytes, respectively. Impressively, the excellent performance of Fe SA /NSC is further confirmed in Zn-air batteries (ZABs) and fuel cells, with high peak power densities (146 mW cm−2 and 0.259 W cm−2). [ABSTRACT FROM AUTHOR]

Nowadays, electric trains are experiencing a transition from diesel fuel to renewable energy. Hybrid electric trains can prove progress from renewable energy, even though they require more than one energy source such as fuel cells and batteries, because renewable energy cannot stand alone. This results in an increase in voltage on the Fuel Cell (FC) which can have an impact on current density and a decrease in voltage, thus requiring a protected DC-DC Converter type circuit to obtain ideal and dynamic condition characteristics. To overcome this problem, the IFBC (Interleaved Full Bridge Circuit) DC-DC Converter is highly recommended as a voltage regulator. There are several methods used to regulate MOSFET’s which in this case affect the IFBC DC DC Converter settings, one of which is the SMC (Sliding Mode Control) method. SMC is a type of non-linear control that functions functionally to control variable structures. However, the application of SMC requires a considerable switching frequency, which has the potential to cause component loss, therefore the switching frequency needs to be limited to that range. To overcome this problem, a method is needed to identify the IFBC output voltage control process using the SMC method in Fuel Cell applications and the software which is considered the most efficient in carrying out this, namely SIMULINK MATLAB software.

Abstract Recently, hydrogen-based distributed generators (DG) have gained significant attention for modern energy generation systems. These modem DGs are typically outfitted with power electronics converters, resulting in harmonic pollution. Furthermore, increasing the growth of modern nonlinear loads may result in exceeding the harmonic beyond the permitted level. This research proposes a framework for optimal incorporation of inverter-based distributed generation (a fuel cell connected to an AC distribution system) for minimizing power losses, enhancing the voltage profile, and limiting both total and individual harmonic distortion according to the IEEE-519 standard. In addition, for accounting system sustainability, the proposed framework considers load variation and the expected rise in demand. Therefore, the suggested framework comprises three stages, which include fundamental and harmonic power flow analysis. The first stage identifies the optimal size and location of the DG in relation to the base load operating condition. While, with the optimal DG of the first stage, the amount of harmonic pollution may violate the limits during a high level of nonlinear load penetration, as a result, the second stage resizes the DG, considering the connection bus of the first stage, to mitigate the harmonics and optimize the system at a higher level of nonlinear load penetration. Both the first and second stages are performed off-line, while the third stage optimizes the system operation during run time according to loading conditions, harmonic pollution, and the available DG capacity of the previous stages. DG’s harmonic spectrum is represented according to recently issued IEEE 1547-2018 for permissible DG’s current distortion limits. The suggested approach is applied and evaluated using an IEEE 33-bus distribution system for various combinations of linear and nonlinear loads. For run-time operation throughout the day, the presented framework reduces the energy losses from 5.281 to 2.452 MWh/day (about 53.57% energy savings). This saving is associated with voltage profile enhancement without violating the permissible standard levels of harmonics and other system constraints.

In this work, a new plastic-intensive medium-pressure plate (MPP), which is part of a fuel-cell system, has been developed together with a steel plate meeting all mechanical and chemical requirements. This newly developed MPP had to achieve the objective of saving weight and package space. The use of compression molding as a manufacturing technique facilitated the use of glass mat thermoplastics (GMT) which has higher E-modules and strength compared to most of the injection molded materials. A steel plate was placed as an insert to help achieve the stiffness requirements. For the development, the existing MPP was benchmarked for its structural capabilities and its underlying functional features. Four different FRP materials were investigated in terms of their chemical and mechanical properties. PP-GMT material, which has both high mechanical performance and resistance against chemicals in the fuel cell fluid, had been chosen. Using the properties of the chosen PP-GMT material, topology optimization was carried out based on the quasi-static load case and manufacturing constraints, which gave a load-conforming rib structure. The obtained rib structure was utilized to develop the final MPP with adherence to the functional requirements of MPP. The developed plastic-intensive MPP exhibits a 3-in-1 component feature with a 55% reduction in package space and an 8% weight reduction. The MPP was virtually analyzed for its mechanical strength and compared with the existing benchmark values. Finally, a press tool was conceptualized and manufactured to fabricate the new plastic-intensive MPP, which was tested in a rig and validated in the FE model.

Objective With the steady advancement of technology and China's dual carbon process, the application of hydrogen energy in urban transportation is increasing. To reduce the overall energy consumption of fuel cell/supercapacitor hybrid power system for virtual-rail trams, an energy management method based on optimal power consumption is proposed. Method Based on the power distribution of virtual-rail trams in different operating states, an instantaneous power consumption function for the hybrid power system is jointly constructed by fitting approximation and combining the power consumption models of fuel cell systems and supercapacitor systems. By optimizing and solving the power consumption function, the optimal output power of the fuel cell system is obtained. The online control capability of the proposed method is verified using a semi-physical simulation platform and actual operational data of the virtual-rail tram. Result & Conclusion Experimental results show that under the control of the proposed method, the fuel cell system maintains a stable output power under complex conditions, with an average electricity-to-hydrogen conversion efficiency of 54.84%. This can effectively reduce the operation and maintenance costs of virtual-rail trams.

Objective Equivalent hydrogen consumption, as a method for optimizing fuel economy, performs poorly in following the state of charge of energy storage systems. Therefore, it is necessary to improve it to achieve dynamic balance of interval state of charge. Method Based on the conventional equivalent hydrogen consumption algorithm, the hydrogen consumption function of the system is optimized. By adding a voltage balance coefficient, it ensures that the supercapacitor will not be overcharged or over-discharged during vehicle operation. Then, through minimization solution, real-time allocation of power to the system is achieved. Result & Conclusion Based on the operational data of virtual-rail trams, the proposed method is validated on a semi-physical simulation platform. Experimental results show that the improved equivalent hydrogen consumption algorithm can achieve energy distribution of hybrid power systems under complex working conditions. The added voltage balance coefficient ensures that the voltage of the supercapacitor at the end of the vehicle interval remains within a reasonable range.

Steam reformers are typically utilized in hydrogen production industry, demanding pressure vessels within methanol reformer systems operating at temperatures between 250-350°C to ensure cost-effectiveness. This characteristic makes them a superior choice for fuel cell systems. However, challenges arise in enhancing hydrogen gas production efficiency while minimizing carbon monoxide emissions. Computational Fluid Dynamics (CFD) has proven effective in addressing these challenges by simulating fluid behavior. This study delves into product production, reactant consumption using CFD, and investigates changes in physical parameters of methanol reformers to optimize their performance. The research involves 140 numerical simulations that examine the relationship between feeds (steam-to-carbon) and various temperatures, aiming to understand the concurrent effect of physical parameters. The results demonstrate that increasing temperature has a more significant impact on hydrogen production compared to increasing the feed ratio. This effect is particularly notable at lower fuel ratios. For example, at a feed ratio of 1, a temperature increase of 11.4°C leads to a substantial 5.4% rise in hydrogen production. However, at a higher feed ratio (1.98), the increase in hydrogen production is only 1.9% with the same temperature increase.

The process of identifying the optimal unknown variables for the creation of a precision fuel-cell performance forecasting model using optimization techniques is known as parameter identification of the proton exchange membrane fuel cell (PEMFC). Recognizing these factors is crucial for accurately forecasting and assessing the fuel cell's performance, as they may not always be included in the manufacturer's datasheet. Six optimization algorithms—the Walrus Optimizer (WO), the Tunicate Swarm Algorithm (TSA), the Harris Hawks Optimizer (HHO), the Heap Based Optimizer (HBO), the Chimp Optimization Algorithm (ChOA), and the Osprey Optimization Algorithm (OOA) were used to compute six unknown variables of a PEMFC. Also, the proposed WO method was compared with other published works' methods such as the Equilibrium Optimizer (EO), Manta Rays Foraging Optimizer (MRFO), Neural Network Algorithm (NNA), Artificial Ecosystem Optimizer (AEO), Slap Swarm Optimizer (SSO), and Vortex Search Approach with Differential Evolution (VSDE). Minimizing the sum squares error (SSE) between the estimated and measured cell voltages requires treating these six parameters as choice variables during optimization. The WO algorithm yielded an SSE of 1.945415603, followed by HBO, HHO, TSA, ChOA, and OOA. Given that WO accurately forecasted the fuel cell's performance, it is appropriate for the development of digital twins for fuel cell applications and control systems for the automobile industry. Furthermore, it was shown that the WO convergence speed was faster than the other approaches studied.

Proton exchange membrane fuel cells (PEMFC) are widely acknowledged as a prospective power source, but durability problems have constrained development. Therefore, a compound prediction framework is proposed in this paper by integrating the locally weighted scatter plot smoothing method (LOESS), uniform information coefficient (UIC), and attention-based stacked generalization model (ASGM) with improved dung beetle optimization (IDBO). Firstly, LOESS is adopted to filter original degraded sequences. Then, UIC is applied to obtain critical information by selecting relevant factors of the processed degraded sequences. Subsequently, the critical information is input into the base models of ASGM, including kernel ridge regression (KRR), extreme learning machine (ELM), and the temporal convolutional network (TCN), to acquire corresponding prediction results. Finally, the prediction results are fused using the meta-model attention-based LSTM of ASGM to obtain future degradation trends (FDT) and the remaining useful life (RUL), in which the attention mechanism is introduced to deduce weight coefficients of the base model prediction results in LSTM. Meanwhile, IDBO based on Levy flight, adaptive mutation, and polynomial mutation strategies are proposed to search for optimal parameters in LSTM. The application of two different datasets and their comparison with five related models shows that the proposed framework is suitable and effective for forecasting the FDT and RUL of PEMFC. [ABSTRACT FROM AUTHOR]

The new hybrid composite materials for PEM fuel cell were synthesized by the UV polymerization of acrylic monomers (acrylonitrile, acrylic acid, ethylene glycol dimethacrylate) and a sulfo aromatic monomer, i.e., sodium styrene sulfonate, and the tetraethoxysilane/3-methacryloxypropyltrimethoxysilane-based sol–gel system. By means of X-ray spectroscopy, the fractal structure of the obtained materials was characterized. Proton conductivity and viscoelasticity of the obtained materials were determined depending on the content of the inorganic component in nanocomposites. Based on impedance studies, an equivalent scheme is proposed that successfully describes the proton conductivity in the synthesized composite's electrolyte membranes. [ABSTRACT FROM AUTHOR]

The hydrogen oxygen fuel cell is a power source with significant potential for development. The air compressor provides ample oxygen for the fuel cell, and as a key component of the air compressor, the performance of the motor greatly impacts the efficiency of the fuel cell. In order to enhance the system performance of high-speed permanent magnet motors, optimization was conducted on the motor's geometric dimensions to minimize rotor loss and maximize power density, taking into account the comprehensive constraints of electromagnetic and mechanical properties. The finite-element method was employed to analyze the motor's performance, conducting a multi-physical field analysis that included electromagnetic field, rotor loss, and mechanical strength analysis, as well as temperature field analysis. Aiming at the problem of high temperature rise in high-speed motor winding, the influence of the cooling water flow rate on the winding temperature rise was analyzed and simulated. Based on the analysis results, the minimum cooling water flow rate was obtained. According to the optimized design results, a prototype of an 18 kW, 100,000 rpm motor was manufactured, and the efficiency and temperature rise were tested. The experimental results verify the correctness and effectiveness of the optimal design. [ABSTRACT FROM AUTHOR]

Using multiple input power sources increases the reliability of electric vehicles compared to a single source. However, the inclusion of other sources exhibits complexity in the controller system, such as computing time, program difficulty, and switching speed to connect or disconnect the input power to load. To ensure optimal performance and avoid overloading issues, the EV system needs sophisticated control. This work introduces a machine-learning-based controller using an artificial neural network to solve these problems. This paper describes the detailed power management control methodology using multiple sources like solar PV, fuel cells, and batteries. Novel control with an instantaneous reference current scheme is used to manage the input power sources to satisfy the power demand of electric vehicles. The proposed work executes the power split-up operation with standard and actual drive cycles and maximum power point tracking for PV panels using MATLAB Simulink. Finally, power management with a machine learning technique is implemented in an experimental analysis with the LabVIEW software, and an FPGA controller is used to control a 48 V, 1 kW permanent-magnet synchronous machine. [ABSTRACT FROM AUTHOR]

High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150–200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis. After the deposition of Pt nanoparticles on the CNF surface, the composite anodes are obtained. A new self-phosphorylating polybenzimidazole of the 6F family is applied to the Pt/CNF surface to improve the triple-phase boundary, gas transport, and proton conductivity of the anode. This polymer coating ensures a continuous interface between the anode and proton-conducting membrane. The polymer is investigated using CO2 adsorption, TGA, DTA, FTIR, GPC, and gas permeability measurements. The anodes are studied using SEM, HAADF STEM, and CV. The operation of the membrane–electrode assembly in the H2/air HT-PEMFC shows that the application of the new PBI of the 6F family with good gas permeability as a coating for the CNF anodes results in an enhancement of HT-PEMFC performance, reaching 500 mW/cm2 at 1.3 A/cm2 (at 180 °C), compared with the previously studied PBI-O-PhT-P polymer. [ABSTRACT FROM AUTHOR]

Developing highly active and durable platinum-based catalysts is crucial for electrochemical renewable energy conversion technologies but the limited supply and high cost of platinum have hindered their widespread implementation. The incorporation of non-noble metals, particularly copper, into Pt catalysts has been demonstrated as an effective solution to reduce Pt consumption while further promoting their performance, making them promising for various electrocatalytic reactions. This review summarizes the latest advances in PtCu-based alloy catalysts over the past several years from both synthetic and applied perspectives. In the synthesis section, the selection of support and reagents, synthesis routes, as well as post-treatment methods at high temperatures are reviewed. The application section focuses not only on newly proposed electrochemical reactions such as nitrogen-related reactions and O2 reduction but also extends to device-level applications. The discussion in this review aims to provide further insights and guidance for the development of PtCu electrocatalysts for practical applications. [ABSTRACT FROM AUTHOR]

In this work, a new plastic-intensive medium-pressure plate (MPP), which is part of a fuel-cell system, has been developed together with a steel plate meeting all mechanical and chemical requirements. This newly developed MPP had to achieve the objective of saving weight and package space. The use of compression molding as a manufacturing technique facilitated the use of glass mat thermoplastics (GMT) which has higher E-modules and strength compared to most of the injection molded materials. A steel plate was placed as an insert to help achieve the stiffness requirements. For the development, the existing MPP was benchmarked for its structural capabilities and its underlying functional features. Four different FRP materials were investigated in terms of their chemical and mechanical properties. PP-GMT material, which has both high mechanical performance and resistance against chemicals in the fuel cell fluid, had been chosen. Using the properties of the chosen PP-GMT material, topology optimization was carried out based on the quasi-static load case and manufacturing constraints, which gave a load-conforming rib structure. The obtained rib structure was utilized to develop the final MPP with adherence to the functional requirements of MPP. The developed plastic-intensive MPP exhibits a 3-in-1 component feature with a 55% reduction in package space and an 8% weight reduction. The MPP was virtually analyzed for its mechanical strength and compared with the existing benchmark values. Finally, a press tool was conceptualized and manufactured to fabricate the new plastic-intensive MPP, which was tested in a rig and validated in the FE model. [ABSTRACT FROM AUTHOR]

Utilizing renewable energy sources to produce hydrogen is essential for promoting cleaner production and improving power utilization, especially considering the growing use of fossil fuels and their impact on the environment. Selecting the most efficient method for distributing power and capacity is a critical issue when developing hybrid systems from scratch. The main objective of this study is to determine how a backup system affects the performance of a microgrid system. The study focuses on power and hydrogen production using renewable energy resources, particularly solar and wind. Based on photovoltaics (PVs), wind turbines (WTs), and their combinations, including battery storage systems (BSSs) and hydrogen technologies, two renewable energy systems were examined. The proposed location for this study is the northwestern coast of Saudi Arabia (KSA). To simulate the optimal size of system components and determine their cost-effective configuration, the study utilized the Hybrid Optimization Model for Multiple Energy Resources (HOMER) software (Version 3.16.2). The results showed that, when considering the minimum cost of energy (COE), the integration of WTs, PVs, a battery bank, an electrolyzer, and a hydrogen tank brought the cost of energy to almost 0.60 USD/kWh in the system A. However, without a battery bank, the COE increased to 0.72 USD/kWh in the same location because of the capital cost of system components. In addition, the results showed that the operational life of the fuel cell decreased significantly in system B due to the high hours of operation, which will add additional costs. These results imply that long-term energy storage in off-grid energy systems can be economically benefited by using hydrogen with a backup system. [ABSTRACT FROM AUTHOR]

For mitigating global warming, polymer electrolyte membrane fuel cells have become promising, clean, and sustainable alternatives to existing energy sources. To increase the energy density and efficiency of polymer electrolyte membrane fuel cells (PEMFC), a comprehensive numerical modeling approach that can adequately predict the multiphysics and performance relative to the actual test such as an acceptable depiction of the electrochemistry, mass/species transfer, thermal management, and water generation/transportation is required. However, existing models suffer from reliability issues due to their dependency on several assumptions made for the sake of modeling simplification, as well as poor choices and approximations in material characterization and electrochemical parameters. In this regard, data-driven machine learning models could provide the missing and more appropriate parameters in conventional computational fluid dynamics models. The purpose of the present overview is to explore the state of the art in computational fluid dynamics of individual components of the modeling of PEMFC, their issues and limitations, and how they can be significantly improved by hybrid modeling techniques integrating with machine learning approaches. Furthermore, a detailed future direction of the proposed solution related to PEMFC and its impact on the transportation sector is discussed. [ABSTRACT FROM AUTHOR]

Hydrogen, due to its high energy density, stands out as an energy storage method for the car industry in order to reduce the impact of the automotive sector on air pollution and global warming. The fuel cell electric vehicle (FCEV) emerges as a modification of the electric car by adding a proton exchange membrane fuel cell (PEMFC) to the battery pack and electric motor, that is capable of converting hydrogen into electric energy. In order to control the energy flow of so many elements, an optimal energy management system (EMS) is needed, where rule-based strategies represent the smallest computational burden and are the most widely used in the industry. In this work, a rule-based operation mode control strategy for the EMS of an FCEV validated by different driving cycles and several tests at the strategic points of the battery state of charge (SOC) is proposed. The results obtained in the new European driving cycle (NEDC) show the 12 kW battery variation of 2% and a hydrogen consumption of 1.2 kg/100 km compared to the variation of 1.42% and a consumption of 1.08 kg/100 km obtained in the worldwide harmonized light-duty test cycle (WLTC). Moreover, battery tests have demonstrated the optimal performance of the proposed EMS strategy. [ABSTRACT FROM AUTHOR]

In the maritime domain, hydrogen fuel cell propulsion and autonomous vessels are two important issues that are yet to be implemented together because of a few challenges. It is obvious that there are several individual safety studies on Maritime Autonomous Surface Ships and hydrogen storage as well as fuel cells based on various risk assessment tools but the combined safety studies that include hydrogen fuel cells on autonomous vessels with recent risk analysis methods are extremely limited. This research chooses the "System-Theoretic Process Analysis" (STPA) method which is a recent method for potential risk identification and mitigation. Both hydrogen and autonomous vessels are analyzed and assessed together with the STPA method. Results are not speculative but rather flexible compared to conventional systems. The study finds a total of 44 unsafe control actions (UCAs) evolved from human and central control unit controllers through STPA. Further, the loss scenarios (LS) are identified that lead to those UCAs so that loss scenarios can be assessed and UCAs can be mitigated for safe operation. The objective of this study is to ensure adequate safety for hydrogen fuel cell propulsion on autonomous vessels. [ABSTRACT FROM AUTHOR]

Conventional electrochemical sensors use voltammetric and amperometric methods with external power supply and modulation systems, which hinder the flexibility and application of the sensors. To avoid the use of an external power system and to minimize the number of electrochemical cell components, a self-powered electrochemical sensor (SPES) for hydrogen peroxide was investigated here. Iron phthalocyanine, an enzyme mimetic material, and Ni were used as a cathode catalyst and an anode material, respectively. The properties of the iron phthalocyanine catalyst modified by graphene nanoplatelets (GNPs) were investigated. Open circuit potential tests demonstrated the feasibility of this system. The GNP-modulated interface helped to solve the problems of aggregation and poor conductivity of iron phthalocyanine and allowed for the achievement of the best analytical characteristics of the self-powered H2O2 sensor with a low detection limit of 0.6 µM and significantly higher sensitivity of 0.198 A/(M·cm2) due to the enhanced electrochemical properties. The SPES demonstrated the best performance at pH 3.0 compared to pH 7.4 and 12.0. The sensor characteristics under the control of external variable load resistances are discussed and the cell showed the highest power density of 65.9 μW/cm2 with a 20 kOhm resistor. The practical applicability of this method was verified by the determination of H2O2 in blood serum. [ABSTRACT FROM AUTHOR]

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