Precise Anchoring of Fe Sites by Regulating Crystallinity of Novel Binuclear Ni‐MOF for Revealing Mechanism of Electrocatalytic Oxygen Evolution

Abstract Bimetallic metal‐organic framework (BMOF) exhibits better electrocatalytic performance than mono‐MOF, but deciphering the precise anchoring of foreign atoms and revealing the underlying mechanisms at the atomic level remains a major challenge. Herein, a novel binuclear NiFe‐MOF with precise anchoring of Fe sites is synthesized. The low‐crystallinity (LC)‐NiFe 0.33 ‐MOF exhibited abundant unsaturated active sites and demonstrated excellent electrocatalytic oxygen evolution reaction (OER) performance. It achieved an ultralow overpotential of 230 mV at 10 mA cm −2 and a Tafel slope of 41 mV dec −1 . Using a combination of modulating crystallinity, X‐ray absorption spectroscopy, and theoretical calculations, the accurate metal sequence of BMOF and the synergistic effect of the active sites are identified, revealing that the adjacent active site plays a significant role in regulating the catalytic performance of the endmost active site. The proposed model of BMOF electrocatalysts facilitates the investigation of efficient OER electrocatalysts and the related catalytic mechanisms.