Medium/High‐Entropy Amalgamated Core/Shell Nanoplate Achieves Efficient Formic Acid Catalysis for Direct Formic Acid Fuel Cell

Abstract High‐entropy alloys (HEAs) have been attracting extensive research interests in designing advanced nanomaterials, while their precise control is still in the infancy stage. Herein, we have reported a well‐defined PtBiPbNiCo hexagonal nanoplates (HEA HPs) as high‐performance electrocatalysts. Structure analysis decodes that the HEA HP is constructed with PtBiPb medium‐entropy core and PtBiNiCo high‐entropy shell. Significantly, the HEA HPs can reach the specific and mass activities of 27.2 mA cm −2 and 7.1 A mg Pt −1 for formic acid oxidation reaction (FAOR), being the record catalyst ever achieved in Pt‐based catalysts, and can realize the membrane electrode assembly (MEA) power density (321.2 mW cm −2 ) in fuel cell. Further experimental and theoretical analyses collectively evidence that the hexagonal intermetallic core/atomic layer shell structure and multi‐element synergy greatly promote the direct dehydrogenation pathway of formic acid molecule and suppress the formation of CO*.