Improved Oxygen Reduction Activity and Durability of Dealloyed PtCo _x Catalysts for Proton Exchange Membrane Fuel Cells: Strain, Ligand, and Particle Size Effects.

ABSTRACT: The development of active and durable catalysts with reduced platinum content is essential for fuel cell commercialization. Herein we report that the dealloyed PtCo/HSC and PtCo₃/HSC nanoparticle (NP) catalysts exhibit the same levels of enhancement in oxygen reduction activity (~4-fold) and durability over pure Pt/C NPs. Surprisingly, ex situ high-angle annular dark field scanning transmission electron microscopy (HAADF STEM) shows that the bulk morphologies of the two catalysts are distinctly different: D-PtCo/HSC catalyst is dominated by NPs with solid Pt shells surrounding a single ordered PtCo core; however, the D-PtCo₃/HSC catalyst is dominated by NPs with porous Pt shells surrounding multiple disordered PtCo cores with local concentration of Co. In situ X-ray a

SUBMITTER: Jia Q 

PROVIDER: S-EPMC4578706 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature