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Durability is the most pressing issue preventing the efficient commercialization of polymer electrolyte membrane fuel cell (PEMFC) stationary and transportation applications. A big barrier to overcoming the durability limitations is gaining a better understanding of failure modes for user profiles. In addition, durability test protocols for determining the lifetime of PEMFCs are important factors in the development of the technology. These methods are designed to gather enough data about the cell/stack to understand its efficiency and durability without causing it to fail. They also provide some indication of the cell/stack’s age in terms of changes in performance over time. Based on a study of the literature, the fundamental factors influencing PEMFC long-term durability and the durability test protocols for both PEMFC stationary and transportation applications were discussed and outlined in depth in this review. This brief analysis should provide engineers and researchers with a fast overview as well as a useful toolbox for investigating PEMFC durability issues.

The large-scale adoption of fuel cells system for sustainable power generation will require the combined use of both multidimensional models and of dedicated testing techniques, in order to evolve the current technology beyond its present status. This requires an unprecedented understanding of concurrent and interacting fluid dynamics, material and electrochemical processes. In this review article, Polymer Electrolyte Membrane Fuel Cells (PEMFC) are analysed. In the first part, the most common approaches for multi-phase/multi-physics modelling are presented in their governing equations, inherent limitations and accurate materials characterisation for diffusion layers, membrane and catalyst layers. This provides a thorough overview of key aspects to be included in multidimensional CFD models. In the second part, advanced diagnostic techniques are surveyed, indicating testing practices to accurately characterise the cell operation. These can be used to validate models, complementing the conventional observation of the current–voltage curve with key operating parameters, thus defining a joint modelling/testing environment. The two sections complement each other in portraying a unified framework of interrelated physical/chemical processes, laying the foundation of a robust and complete understanding of PEMFC. This is needed to advance the current technology and to consciously use the ever-growing availability of computational resources in the next future.

Studies on proton exchange membrane fuel cells [PEMFCs] have shown that poor fluid distribution can lead to a higher probability of concentration, ohmic, and activation losses which affects the overall electrochemical and power output performance as well as reduced cell durability. Hence, understanding fluid dynamics are imperative to identify strategies that will improve the fluid distribution uniformity and optimise reactant transport. Most fluid flow studies for PEMFCs are done through computational fluid dynamic [CFD] simulations as it is a cost-saving research method with dependable accuracy levels. In some cases, real-life experiments are executed concurrently to justify the simulation results and theories made. However, there are instances where simplifications are needed for both CFD simulations and experiments for easier and clearer fluid analysis. This short review will first discuss the simplification strategies used to simulate PEMFC models in both 2-dimensional [2D] and 3-dimensional [3D] dimensions, covering theories or concepts that can prove the dependability of the methods employed. Then, the next part will explain the validation techniques applied to justify simulation results, including the types of measuring methods employed to generate the clearest capture of fluid flow and behaviour in the PEMFC models. The overall discussion will provide a better insight into choosing a suitable combination of simplification, validation, and measuring methods for increased quality and accuracy of future studies on fluid flow analysis.

This paper reviews the literature on the synthesis of carbon nanotube- and nanofiber-supported Pt electrocatalysts for proton exchange membrane (PEM) fuel cell catalyst loading reduction through the improvement of catalyst utilization and activity, especially focusing on cathode nano-electrocatalyst preparation methods. The features of each synthetic method were also discussed based on the morphology of the synthesized catalysts. It is clear that synthesis methods play an important role in catalyst morphology, Pt utilization and catalytic activity. Though some remarkable progress has been made in nanotube- and nanofiber-supported Pt catalyst preparation techniques, the real breakthroughs have not yet been made in terms of cost-effectiveness, catalytic activity, durability and chemical/electrochemical stability. In order to make such electrocatalysts commercially feasible, cost-effective and innovative, catalyst synthesis methods are needed for Pt loading reduction and performance optimization.

The performance of a proton exchange membrane electrolyzer cell directly depends on the arrangement of flow field in bipolar plates (BPs). The design of flow field in BPs should be in a way that a uniform distribution of flow is achieved; in this regard, a three-dimensional model of a new flow field arrangement with a cross section of 64 cm 2 is proposed and the distribution of current density, temperature, and pressure drop is investigated. A numerical model is carried out at the steady-state, single-phase, and non-isothermal condition based on finite volume control method. The continuity, momentum, species, energy and electric charge balance equations together with electrochemical kinetics relations in different regions of PEM electrolyzer are solved in a single-domain model. The results of numerical model are compared against experimental data, and an acceptable agreement is observed at low and medium currents densities. The results reveal that the spiral flow field yields a uniform distribution of produced hydrogen and current density. Moreover, the proposed flow field design leads to a uniform distribution of temperature through the channel path. The availability of water and current density at vertical paths of the flow field are higher.

In the context of the evolving energy landscape, the need to harness renewable energy sources (RESs) has become increasingly imperative. Within this framework, hydrogen emerges as a promising energy storage vector, offering a viable solution to the flexibility challenges caused by the inherent variability of RESs. This work investigates the feasibility of integrating a hydrogen-based energy storage system within an energy community in Barcelona, using surplus electricity from photovoltaic (PV) panels. A power-to-power configuration is modelled through a comprehensive methodology that determines optimal component sizing, based on high-resolution real-world data. This analysis explores how different operational strategies influence the system’s cost-effectiveness. The methodology is thus intended to assist in the early-stage decision-making process, offering a flexible approach that can be adapted to various market conditions and operational scenarios. The results show that, under the current conditions, the combination of PV generation, energy storage, and low-cost grid electricity purchases yield the most favourable outcomes. However, in a long-term perspective, considering projected cost reductions for hydrogen technologies, strategies including energy sales back to the grid become more profitable. This case study offers a practical example of balancing engineering and economic considerations, providing replicable insights for designing hydrogen storage systems in similar energy communities.

Polymer electrolyte membrane fuel cells (PEMFCs) expect a promising future in addressing the major problems associated with production and consumption of renewable energies and meeting the future societal and environmental needs. Design and fabrication of new proton exchange membranes (PEMs) with high proton conductivity and durability is crucial to overcome the drawbacks of the present PEMs. Acid-doped polybenzimidazoles (PBIs) carry high proton conductivity and long-term thermal, chemical, and structural stabilities are recognized as the suited polymeric materials for next-generation PEMs of high-temperature fuel cells in place of Nafion® membranes. This paper aims to review the recent developments in acid-doped PBI-based PEMs for use in PEMFCs. The structures and proton conductivity of a variety of acid-doped PBI-based PEMs are discussed. More recent development in PBI-based electrospun nanofiber PEMs is also considered. The electrochemical performance of PBI-based PEMs in PEMFCs and new trends in the optimization of acid-doped PBIs are explored.

This review presents methanol as a potential renewable alternative to fossil fuels in the fight against climate change. It explores the renewable ways of obtaining methanol and its use in efficient energy systems for a net zero-emission carbon cycle, with a special focus on fuel cells. It investigates the different parts of the carbon cycle from a methanol and fuel cell perspective. In recent years, the potential for a methanol economy has been shown and there has been significant technological advancement of its renewable production and utilization. Even though its full adoption will require further development, it can be produced from renewable electricity and biomass or CO2 capture and can be used in several industrial sectors, which make it an excellent liquid electrofuel for the transition to a sustainable economy. By converting CO2 into liquid fuels, the harmful effects of CO2 emissions from existing industries that still rely on fossil fuels are reduced. The methanol can then be used both in the energy sector and the chemical industry, and become an all-around substitute for petroleum. The scope of this review is to put together the different aspects of methanol as an energy carrier of the future, with particular focus on its renewable production and its use in high-temperature polymer electrolyte fuel cells (HT-PEMFCs) via methanol steam reforming.

Hydrogen fuel cell vehicles can complement other electric vehicle technologies as a zero-emission technology and contribute to global efforts to achieve the emission reduction targets. This article spotlights the current deployment status of fuel cells in road transport. For this purpose, data collection was performed by the Advanced Fuel Cells Technology Collaboration Programme. Moreover, the available incentives for purchasing a fuel cell vehicle in different countries were reviewed and future perspectives summarized. Based on the collected information, the development trends in the last five years were analyzed and possible further trends that could see the realization of the defined goals derived. The number of registered vehicles was estimated to be 51,437 units, with South Korea leading the market, with 90% of the vehicles being concentrated in four countries. A total of 729 hydrogen refueling stations were in operation, with Japan having the highest number of these. The analysis results clearly indicate a very positive development trend for fuel cell vehicles and hydrogen refueling stations in 2021, with the highest number of new vehicles and stations in a single year, paralleling the year’s overall economic recovery. Yet, a more ambitious ramp-up in the coming years is required to achieve the set targets.

The last decade’s research on the performance of proton-exchange membrane direct ethanol fuel cells (PEM-DEFCs) and anion exchange membrane direct ethanol fuel cells (AEM-DEFCs) is included in the present review. Future research challenges are identified along with potential strategies to overcome them. Pt-containing or Pt-free PEM-DEFCs that use acid proton-exchange membranes (typically Nafion type) exhibit relatively low performance (i.e., the state-of-the-art peak power density is 110 mW cm−2 at 145 °C over 4 mg of total Pt loading), while Pt-containing or Pt-free AEM-DEFCs that use low-cost anion-exchange membrane have recently exhibited better performance values (i.e., the state-of-the-art peak power density is about 185 mW cm−2 at 80 °C over Au-modified Pd catalysts supported on carbon nanotubes. The required faster kinetics of the ethanol oxidation and especially for the oxygen reduction reaction seem to be satisfied from one side by the AEM-DEFCs and from the other by PEM-DEFCs only if working at intermediate temperature values (>150 °C). Moreover, new possibilities of using less expensive metal catalysts (as silver, nickel, and palladium) are opening mainly for AEM-DEFCs and the last years for PEM-DEFCs too. Finally, it is worth to be noticed that the best value ever reported (peak power density is 360 mW cm−2 at 60 °C) has been obtained in a very promising alkaline-acid direct ethanol fuel cell (AA-DEFC).