Modulation of the Electronic Structure of High-Entropy FeCoNiMnAl Layered Double Hydroxides Boosting Oxygen Evolution Reaction Performance

The development of efficient and durable non-precious metal electrocatalysts for the oxygen evolution reaction (OER) is critical for enabling large-scale hydrogen production. High-entropy materials have garnered a significant amount of interest due to their unique multielement compositions, synergistic effects, and entropy-driven structural stability. However, the electronic interaction mechanisms among the multiple metallic elements remain insufficiently understood. In this study, a pentametallic high-entropy LDH catalyst (FeCoNiMnAl) was in situ synthesized on nickel foam via one-step hydrothermal method. The catalyst has a three-dimensional layered microflower structure, which combines a large specific surface area and a crystalline/amorphous heterogeneous interface, which facilitates mass transport and exposes abundant active sites. Electrochemical tests show that this catalyst requires only a 242 mV overpotential to achieve a current density of 100 mA cm^-2 in 1 M KOH. Furthermore, an alkaline anion exchange membrane electrolyzer utilizing the high-entropy LDH catalyst achieves a current density of 1 A cm^-2 at a voltage of 2.02 V, with negligible performance degradation over continuous operation for 160 h. Theoretical calculations reveal that the strong orbital overlap effect between the multimetal elements adjusts the d-band center, optimizing the adsorption energy of oxygen-containing intermediates. This study confirms that a high-entropy strategy can effectively synergize the enhancement of both activity and stability of LDHs catalysts and provides a direction for advancing the industrial application of water electrolysis technology.