Lattice Boltzmann simulation of PEMFC catalyst degradation through electrochemical Ostwald ripening

Abstract

This project focuses on simulating the degradation of PEMFC catalysts, employing the Lattice Boltzmann Method (LBM) and grounded in the PALABOS library. Using the LBM, microstructure-resolved simulations can be performed to study the impact of catalyst layer material properties on degradation behavior. Specifically, the study centers on modeling Electrochemical Ostwald Ripening. In this phenomenon, smaller platinum particles dissolve and redeposit onto larger ones, driven by platinum ion concentration gradients between them. Over time, this leads to the growth of larger particles at the expense of smaller ones, reducing the overall electrochemical active surface area (ECSA), leading to a loss of performance. The presented model describes dissolution and precipitation using local reactive boundary conditions [2] coupled to the diffusion of platinum ions between the particles. By systematically modifying the microstructure, we seek to understand its effect on catalyst degradation, aiming to identify an optimized range of structural parameters that minimize degradation and enhance catalyst durability.