In situ atomic-scale observation of oxygen-driven core-shell formation in Pt₃Co nanoparticles.

ABSTRACT: The catalytic performance of core-shell platinum alloy nanoparticles is typically superior to that of pure platinum nanoparticles for the oxygen reduction reaction in fuel cell cathodes. Thorough understanding of core-shell formation is critical for atomic-scale design and control of the platinum shell, which is known to be the structural feature responsible for the enhancement. Here we reveal details of a counter-intuitive core-shell formation process in platinum-cobalt nanoparticles at elevated temperature under oxygen at atmospheric pressure, by using advanced in situ electron microscopy. Initial segregation of a thin platinum, rather than cobalt oxide, surface layer occurs concurrently with ordering of the intermetallic core, followed by the layer-by-layer growth of a platinum shell vi

SUBMITTER: Dai S 

PROVIDER: S-EPMC5547122 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature