One-Step Synthesis of Supported High-Index Faceted Platinum-Cobalt Nanocatalysts for an Enhanced Oxygen Reduction Reaction

The slow rate of the oxygen reduction reaction (ORR) is the main barrier limiting the commercialization of proton exchange membrane fuel cells on an industrial scale. Here, we report a one-step synthetic strategy of a class of carbon-supported Pt-Co alloy concave nanocubes (NCs) with {hk0} high-index facets with a high ORR activity. The concave degree of the Pt-Co alloy is tunable through adjusting the amount of short carbon-chain capping agent-n-butylamine. In the growth process, carbon black serves as a dispersant to avoid the nanoparticle aggregation and thus favor the generation of concave NCs in addition to the function as the support for Pt-Co nanoparticles. The carbon-supported Pt-Co concave NCs with 22% Pt-Co by weight deliver a specific activity of 2.34 mA cm(-2) and mass activity of 0.26 A mg(-1) Pt toward ORR, representing 6.5-fold and two-fold enhancement, respectively, relative to the state-of-the-art commercial Pt/C. After 5000 cycles of the accelerated durability test, the mass activity of carbon-supported Pt-Co concave NCs is still higher than that of pristine commercial Pt/C.