Convex Cube‐Shaped Pt34Fe5Ni20Cu31Mo9Ru High Entropy Alloy Catalysts toward High‐Performance Multifunctional Electrocatalysis

Abstract High entropy alloy (HEA) catalysts exhibit excellent multifunctional catalytic performance due to the synergistic effect of multi‐metal components. However, shape‐controlled synthesis of such kinds of HEA catalysts, especially those with high index facets, still faces great challenges, limiting further enhancement of their catalytic performance. Herein, one‐pot synthesis of convex cube‐shaped Pt 34 Fe 5 Ni 20 Cu 31 Mo 9 Ru HEA catalysts which possess rich (310) facets and a diagonal crystalline size of 38.5 nm is reported. Transmission electron microscopy measurements indicate cube‐shaped nanocrystals are obtained first and further selective growth of pyramid on each facet of the cube‐shaped nanocrystal results in a convex cube shape. Pt 34 Fe 5 Ni 20 Cu 31 Mo 9 Ru HEA catalysts show excellent electrocatalytic performance toward the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER), which exhibit a half‐wave potential of 0.87 V for ORR in 0.1 m HClO 4 , and overpotential of 20 and 259 mV for HER and OER at a current density of 10 mA cm −2 in an alkaline medium. A control experiment and density functional theory calculation indicate that the Ru element plays a decisive role in both the formation of the convex cube shape and also the high catalytic performance.