Carbothermal Shock Synthesis of Lattice Oxygen-Mediated High-Entropy FeCoNiCuMo-O Electrocatalyst with a Fast Kinetic, High Efficiency, and Stable Oxygen Evolution Reaction

Efficient oxygen evolution reaction (OER) catalysts with fast kinetics, high efficiency, and stability are essential for scalable green production of hydrogen. The rational design and fabrication of catalysts play a decisive role in their catalytic behavior. This work presents a high-entropy catalyst, FeCoNiCuMo-O, synthesized via carbothermal shock. Synergistic optimization of the adsorption evolution mechanism (AEM) and lattice oxygen mechanism (LOM) was realized and demonstrated through the combination of <i>in situ</i> spectra/mass spectrometry and chemical probe analysis in FeCoNiCuMo-O. Furthermore, the robust stability is reinforced by the inherent properties conferred by the high-entropy design. The catalyst exhibits outstanding performance metrics, featuring an exceptionally low Tafel slope of 41 mV dec^-1, a low overpotential of 272 mV at 10 mA cm^-2, and a commendable endurance (a mere 2.2% voltage decline after a 240-h continuous chronopotentiometry test at 10 mA cm^-2). This study advances the development of efficient, durable OER electrocatalysts for sustainable hydrogen production.