Low‐Coordination Indium Single‐Atom Sites Anchored on a Metal‐Organic Framework Single‐Layer Boosts Electroreduction of CO 2 Into Formic Acid

, 100% purity) free of electrolyte contamination, achieving a concentration 1.5-fold higher than the current state-of-the-art. Mechanistic investigations identify dual enhancement mechanisms: i) the low-coordinated In(III) single-atom sites facilitate dual *HCOO intermediate binding, enhancing reaction kinetics beyond conventional single-intermediate adsorption on high-coordination metal centers; and ii) the single-layer MOF configuration optimizes active site exposure, synergistically maximizing catalytic efficiency.