Orthogonal Control of Lattice Oxygen Activation and Oxygen Evolution Reaction Suppression via “Molecular Gates” for High‐Efficiency Nitrile Electrosynthesis

A fundamental barrier to industrial electrosynthesis is the inescapable trade-off between activity and selectivity at high current densities, where parasitic reactions overwhelm the desired interfacial chemistry. Here, we introduce a bioinspired interfacial decoupling strategy using hexamethylphosphoramide (HMPA) to resolve this challenge for nitrile electrosysthesis. The activation of lattice oxygen for substrate dehydrogenation via metal-ligand charge redistribution, and the suppression of OH^--driven oxygen evolution reaction (OER) via electrostatic shielding by hydrophobic alkyl chains are concurrently controlled. As a result, we achieved simultaneously high activity (1.37 V @300 mA cm^-2), near-unity selectivity (93.3% Faradaic efficiency (FE)), and pharmaceutical-grade purity for propionitrile production. Further reinforced by exceptional stability (>300 h at industrially relevant current densities), a record production rate (143.86 mg cm^-2 h^-1), and ∼30% energy reduction, the system significantly outperforms state-of-the-art benchmarks. Furthermore, this electrolyte-catalyst co-optimization strategy proves universal across primary/secondary amines, offering a blueprint for sustainable chemical manufacturing beyond fossil-fueled processes.