Magnetic Properties\nand Electrocatalytic Oxygen Evolution\nPerformance of a Medium-Entropy Metal Nitride

The advancement of highly efficient and durable electrocatalysts\nfor the oxygen evolution reaction (OER) is essential for advancing\nsustainable hydrogen energy technologies. In this study, we synthesized\na novel medium-entropy metal nitride (MEMN), FeCoNiZnN, with an antiperovskite\nstructure through a solid-phase reaction method. FeCoNiZnN displays\nferromagnetism above 350 K and demonstrates exceptional OER performance\nwith a specific activity 141 times greater than that of Co<sub>3</sub>ZnN, with an overpotential of only 301 mV at 10 mA cm<sup>–2</sup>, comparable to that of commercial RuO<sub>2</sub> catalysts, and\nexhibits superior durability. Density functional theory (DFT) calculations\nreveal that the enhanced catalytic performance is due to optimized\nelectronic properties and improved <i>d</i>-band centers,\nwhich enhance the adsorption of oxygen intermediates and reduce the\nfree energy barriers at the rate-determining step. This study highlights\nthe potential of MEMNs in developing advanced magnetic materials and\nnovel electrocatalysts.