Mercapto‐Carboxyl Jointly Coordinated Frameworks for Elucidating Heterometallic Synergy in Oxygen Evolution Electrocatalysis

Deciphering heterometallic synergy in the oxygen evolution reaction (OER) remains a challenge due to the structural complexity of traditional catalysts. We report a series of fluorinated metal–organic frameworks, M‐dfdmt (M = Fe, Co, Ni), featuring a “mercapto‐carboxyl” (mercarb) coordination motif that marries electrical conductivity with catalytic site accessibility. Within this architecture, soft thiolate groups establish deep M–S orbital hybridization for continuous charge transport, while labile [MO 6 ] units serve as primary active sites. While homoleptic Ni‐dfdmt exhibits high intrinsic conductivity (7.34 × 10 −4 S cm −1 ), the heterometallic NiFe‐dfdmt achieves superior OER activity. Theoretical charge population analyses, corroborated by X‐ray photoelectron spectroscopic binding energy shifts, reveal that coupling Ni and Fe induces a directed electron density shift and establishes local electric‐field gradients between heterometallic centers, which optimizes the electronic environment for intermediate adsorption. Kinetic studies, including a reaction order of 1.04 with respect to OH − , further support a lattice oxygen mechanism (LOM). By isolating heterometallic crosstalk within a crystallographically precise lattice, this work clarifies how electronically rewired coordination environments can modulate intermediate binding and facilitate charge transfer in molecularly defined electrocatalysts.