High index surface-exposed and composition-graded PtCu3@Pt3Cu@Pt nanodendrites for high-performance oxygen reduction

Alloying and nanostructuring are two strategies used to facilitate the efficient electrocatalysis of oxygen reduction reaction (ORR) by Pt, where high index surfaces (HISs) Pt exhibit superior activity for ORR. Here, we report fabrication PtCu3 nanodendrites possessing rich spiny branches exposing n(111) × (110) HISs. The dendrites were formed through an etching-modulated seeding growing strategy. Specifically, oxidative atmosphere was initially applied form concaved nanocubes Pt-Cu seeds, which then switched inert promote explosive growth dendrites. Separately, or failed produce this hyperbranched structure. Electrochemical dealloying produced Pt3Cu shells with Pt-rich HIS-exposed dendrite structures maintained. resulting PtCu3@Pt3[email protected] in 0.1 M HClO4 exhibited excellent mass area specific activities ORR, 14 24 times higher than that commercial Pt/C, respectively. DFT calculations revealed Cu alloying HISs both contributed significantly enhanced binding energy on step sites approached optimal value achieve a near peak-top ORR activity.