Reports

Platinum (Pt) is a highly efficient electrocatalyst for both the cathodic oxygen reduction reaction (ORR) in fuel cells (and metal-air batteries) and the hydrogen evolution reaction (HER) in alkaline electrolyzers (1– 18). However, the high cost and scarcity of Pt are key obstacles for its broad deployment in fuel cells and metal-air batteries for both stationary and portable applications. Intense research efforts have been focused on developing high-performance electrocatalysts with minimal precious metal content and cost (1–15). Specifically, alloying Pt with non-noble metals can reduce the Pt content of electrocatalysts by increasing their intrinsic activity (1–12). We demonstrated that the formation of a nano-segregated Pt(111)-Skin structure over a bulk single-crystal alloy with Pt3Ni composition enhanced the ORR activity by two orders of magni-tude (vs. Pt/C) through altered electronic structure of Pt surface atoms (1). However, these materials cannot be easily integrated into electro-chemical devices but their outstanding catalytic performance needs to b