Tunable Multimetallic Single‐Atom Catalysts for Efficient Hydrogen Evolution Reaction

Abstract Designing single‐atom catalysts (SACs) with various metal atoms can significantly expand their range of applications. In this study, a scalable strategy is developed to synthesize a series of transition metal (TM = Mn, Fe, Co, Ni, and Cu) SACs with widely tunable compositions, progressing from unitary to binary (CoNi), ternary (MnCoNi), quaternary (MnFeCoNi), and quinary (MnFeCoNiCu) atoms. High loadings of TM atoms (>10 wt%) are successfully embedded in porous N‐doped carbon nanoparticle supports derived from pyrolyzed zeolitic imidazole frameworks (ZIF‐8). All SACs feature a TM–N 4 coordination structure. Among them, the MnCoNi ternary composition exhibited the greatest synergistic effect, enhancing electrocatalytic activity toward the alkaline hydrogen evolution reaction (HER). Ex situ X‐ray absorption fine structure data indicate that the multicomponent SACs facilitates more efficient electrolyte adsorption, thereby accelerating the HER kinetics.