Modeling an ordered nanostructured cathode catalyst layer for proton exchange membrane fuel cells

► Presents a 3D model of an ordered nanostructured CCL for PEM fuel cells. ► Incorporates all the relevant processes in various phases of a nanostructured CCL. ► Dissolved O2 transport through the Nafion film is a performance-limiting factor. ► Knudsen diffusion effect is negligible above CNT spacing of 25 nm. ► Nafion film thickness of 10 nm is found to be optimum.