Multidimensional nanostructured membrane electrode assemblies for proton exchange membrane fuel cell applications

Developing membrane electrode assemblies (MEAs) with high performance and low cost is key to promoting the practical applications of proton exchange membrane fuel cells (PEMFCs), including direct methanol fuel cells (DMFCs). Consequently, extensive efforts have been dedicated to developing nanostructured MEAs, which are believed to possess advantages in increasing catalyst utilization, maximizing the three-phase boundary, enhancing mass transport and improving operation stability. This review describes the recent progress in nanostructured MEAs equipped with multidimensional nanostructured catalysts, catalyst layers and proton exchange membranes for PEMFCs and DMFCs. The structural features and construction methods of nanostructured MEAs based on one-dimensional nanostructures such as nanowires, nanotubes and nanofibers are first reviewed. Afterwards, an overview of recent advances in fabricating ordered nanostructured MEAs with three-dimensional nanostructures based on different types of materials is presented. Finally, some perspectives on current limitations and future research directions of nanostructured MEAs are proposed.