Synergy of MoS₂‐Confined Fe and Co Atoms Enhances Hydrogen Evolution

Abstract MoS 2 has emerged as a promising low‐cost candidate for the acidic hydrogen evolution reaction (HER). However, its catalytic performance is limited by the chemical inertness of the dominating MoS 2 ‐basal plane. Herein, it is reported that the catalytic activity of MoS 2 for HER can be significantly boosted by the synergy of MoS 2 lattice‐confined Fe and Co atoms (FeCo‐MoS 2 ). The catalyst exhibits a superior activity with a low overpotential of 356 mV at an industrial‐level high current density of 1 A cm −2 , markedly surpassing those of the commercial Pt/C catalyst and previously reported MoS 2 ‐based non‐noble metal catalysts, and works stably for over 350 h. Multiple characterizations combined with theoretical calculations demonstrate that the co‐confinement of Fe and Co atoms synergistically optimizes the energy levels of valence electronic states of neighboring sulfur atoms compared with the situations of solely confining Fe or Co, thereby improving the adsorption of protons and facilitating the electron‐transfer kinetics in the Volmer and Heyrovsky steps of HER.