Nanosized Pt-La alloy electrocatalysts with high activity and stability for the oxygen reduction reaction

Abstract

Although alloying with late transition metals such as Ni, Co, and Fe significantly enhances the oxygen reduction reaction (ORR) activity, stability issues have inhibited further performance improvements of fuel cells. Acidic media (pH < 1) at high electrochemical potential (>0.7 V-RHE) induced metal dissolution and also affected the catalytic activity. In terms of the stability issues of alloy nanoparticles, we focused on the early-transition-metal alloy system (Pt-La) as a promising candidate to realize both high activity and stability. The high activity and stability were attributed to electronic perturbations, which were the changes in the filling of the d band and the heat of alloy formation, as confirmed by experimental results. (C) 2014 Elsevier B.V. All rights reserved.