First-Principles Study on Alloy Nanoparticles for Polymer Electrolyte Fuel Cell Catalyst

Abstract

The reduction of Pt used as electrocatalyst is one of the central issues toward the large-scale penetration of the technology into the society. For this purpose, it is important to understand the essential nature of Pt-based electrocatalyst. First-principles method based on density functional theory is applied to investigate the stability and the structural features of Pt-based electrocatalyst. Nanoparticle models with 711 atoms, which correspond to ca. 3 nm in diameter, are calculated by the massive parallel computer system in this study. Pt608Co103 models with Pt-skin and solid solution configurations are compared. The stability of Pt608Co103 at the operation temperature is discussed on the basis of excess energy and configuration entropy. The interatomic distances in the nanoparticle is analyzed for Pt608Co103 and Pt711 nanoparticle models as well as Pt bulk model.