Proton exchange membrane fuel cells (PEMFCs) have recently reached a remarkable level of performance. Their high cost, however, has a negative impact on the market penetration. Present work reviews recent developments of advanced catalytic layer architectures proposed as an alternative to the conventional ones in view of decreasing the Pt loading and increasing the Pt-specific power density. Various promising approaches will be discussed starting from the widely known 3M's nanostructured thin films to less publicized Pt-decorated arrays of aligned carbon nanotubes/nanofibers. The issues to be addressed span from the preparation of three-dimensionally ordered layers, to fundamental questions related to the optimization of their spatial structure to attain the maximum efficiency of material utilization and activity. WIREs Energy Environ 2014, 3:505–521. doi: 10.1002/wene.110

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Conflict of interest: The authors have declared no conflicts of interest for this article.