First Principles Computational Study on the Electrochemical Stability of Pt-Co Alloy Nanocatalysts for Fuel Cell Applications

Abstract

Novel design of Pt-M alloy catalysts for a Polymer Electrolyte Fuel Cell (PEMFC) developed over the last decade has substantially not only saved the materials cost but also enhanced oxygen reduction reaction activity. Currently, one of the most challenging issues is how to empower the nanocatalysts electrochemical stability for a wide commercialization of PEMFC as long-term power sources of transportation vehicles. Using first principles and multi-scale computations this thesis investigates the underlying mechanism of the electrochemical degradation of Pt-Co alloy nanocatalysts. The objectives of the thesis are to identify atomic level descriptors of the mechanism and to figure out novel ways to increase the electrochemical durability. To achieve the goals we setup model systems of Pt-Co nanoparticles as function of Co composition and the size of the particle. And then, Monte Carlo simulations combined with the cluster variation method will provide thermodynamically the most stable configuration of Pt-Co alloy catalysts for any given temperature and alloy composition as well as a chemical potential of oxygen atom. To ⓒ 2013 DGIST