A Hierarchical Model for Oxygen Transport in Agglomerates in the Cathode Catalyst Layer of a Polymer-Electrolyte Fuel Cell

Numerous experiments have demonstrated that oxygen transport losses in conventional cathode catalyst layers in polymer-electrolyte fuel cells increase as the amount of platinum is decreased. This paper develops an analytical agglomerate model for kinetics and transport that incorporates localized spherical diffusion and adsorption kinetics at the scale of the catalyst nanoparticles. This hierarchical structure provides an improved description of mass transport inside agglomerates at high fluxes. Predictions using morphological parameters and physical properties from the literature are commensurate with published investigations into the influence of platinum loading on oxygen transport. (C) The Author(s) 2018. Published by ECS.