Modeling of micro/meso-scale reactive transport phenomena in catalyst layers of proton exchange membrane fuel cells

In this article, we outline and review the methods that are currently used to simulate the micro/meso-scale flow and reactive transport processes in the porous catalyst layers (CLs) of a fuel cell. The approaches beyond the atomic scale (molecular dynamics) and below the conventional continuum scale (Navier–Stokes solvers) use coarse-grained pseudo-particles which can either move on a fixed lattice or continuously in space. The focus is mainly put on the development of the off-lattice pseudo-particle models, such as coarse-grained molecular dynamics (CG-MD), dissipative particle dynamics (DPD) and smoothed particle hydrodynamics (SPH) methods. As an example, a CG-MD method is performed as a microscopic structure reconstruction technique to reflect the self-organized phenomena during the formation steps of a CL. In addition, we also highlight the combined nano-scale elementary kinetic processes and the issues on the coupling of DPD and SPH to finite element (FE) modeling techniques. This article also highlights the critical aspects and addresses the future trends and challenges for these models. Copyright , Oxford University Press.