Ni/Cu Regulating Nitrogen‐Doped Porous Carbon as Electrocatalyst for Oxygen Reduction Reaction

Abstract Transition metal and nitrogen co‐doped carbon materials have been widely investigated as promising electrocatalysts for oxygen reduction reaction (ORR). Incorporating two different metals in N‐doped carbon may synergistically improve the catalytic activity. Herein, Ni/Cu incorporated N‐doped porous carbon materials (Ni 1‐x Cu x ‐N−C) with different Ni/Cu ratios were prepared by a direct carbonization of the metal‐organic complexes which were obtained via a NaOH‐mediated organometallic reaction of metal ions and benzimidazole. It is found that the Ni/Cu ratio significantly alters the Ni 1‐x Cu x particle sizes, the surface morphology, the specific surface area, and the pore structure of the catalysts, eventually affecting the ORR activities. Ni 0.7 Cu 0.3 ‐N−C exhibits the best ORR activity among the studied Ni 1‐x Cu x ‐N−C catalysts with a half‐wave potential of 0.783 V and a limiting current density of 4.85 mA cm −2 in alkaline medium. Density functional theory calculations confirm that the synergistic effect of bimetallic Ni/Cu can optimize the adsorption/desorption features and promote the ORR catalytic activities.