Research progress on clay-based hybrid proton exchange membranes for fuel cells.

Proton exchange membrane fuel cells (PEMFCs) represent a promising clean energy technology for efficient power generation, offering significant potential to address both carbon emission reduction and global energy challenges. As the core component of fuel cells, proton exchange membranes (PEMs) serve dual functions of electrode separation and proton conduction. However, conventional membrane materials still face substantial limitations in performance under high-temperature/low-humidity conditions and long-term operational stability. Clay minerals or layered silicates, as inorganic fillers, have attracted considerable attention for composite membranes due to their abundant availability, low cost, tunable structure, high specific surface area, and versatile surface chemistry. Consequently, incorporating clay into polymer matrices has been explored to enhance the proton conductivity, water uptake, mechanical properties, and stability of PEMs. This review systematically summarizes recent advances in clay-based PEMs for fuel cell applications, with particular emphasis on the microstructural construction and regulation of proton transport channels, as well as the enhancement of proton transfer characteristics in clay-based hybrid PEMs. Furthermore, a forward-looking perspective on future research directions for developing high-performance clay-based PEMs is delineated.