Recent advances in membrane systems for sustainable proton exchange membrane fuel cells: A review

Proton exchange membrane fuel cells (PEMFCs) are essential for clean energy conversion, offering a promising alternative to traditional fossil fuel-based systems. However, challenges such as high costs, limited durability, and reliance on petrochemical-derived materials hinder their widespread adoption. Recent advancements focus on sustainable bio-based and hydrocarbon-based membranes designed to address these issues and improve PEMFC performance. This review explores the development of bio-based polymer electrolytes, including cellulose, chitosan, and lignin derivatives, which demonstrate enhanced proton conductivity (exceeding 0.1 S/cm under hydrated conditions) and thermal stability (operating above 120°C). These materials also mitigate fuel crossover and chemical degradation. Additionally, nanocomposite membranes incorporating metal oxides, metal–organic frameworks, and radical scavengers have been engineered to improve water retention, mechanical strength, and membrane longevity, significantly enhancing the performance and lifespan of PEMFCs. Innovations in catalyst materials, such as biomass-derived carbon supports and reduced platinum group metal loading, have contributed to lower system costs and improved efficiency. Despite these advancements, long-term durability remains a critical challenge, particularly regarding water management and chemical degradation under operational conditions. This review emphasizes the importance of continued research to overcome these remaining challenges. Ultimately, bio-based polymers and advanced catalysts are expected to be pivotal in advancing PEMFC sustainability and facilitating their integration into future renewable energy systems.