The role of nanomaterials in addressing challenges in proton exchange membranes: A comprehensive review

Proton exchange membranes (PEMs) are vital for electrochemical devices like fuel cells, yet benchmark materials such as Nafion face limitations in cost and performance at high temperatures or low humidity. Incorporating nanomaterials into the polymer matrix is a key strategy to overcome these issues. This review provides a mechanistic analysis of how different nanofiller classes including carbon structures, inorganic oxides, and metal-organic frameworks (MOFs) enhance PEM properties like water retention, fuel crossover, and durability. More importantly, we highlight how next-generation engineered fillers can elevate performance to unprecedented levels. For instance, recent advances with rationally designed hybrid nanofillers have demonstrated significant improvements in power density and stability, even under the most challenging operating conditions. By focusing on nanoscale structure-property relationships, this work outlines a roadmap for the rational design of cost-effective, high-performance PEMs.