Glutathione-Mediated Biomimetic NO Activation with Coordination Capsules for NH₃ and α-Amino Acid Electrosynthesis

The conversion of nitrogen oxides into nitrogen-containing chemicals is critical to the global nitrogen cycle, but utilizing resources derived from NO_x gas presents significant challenges. Herein we report a biomimetic strategy to incorporate a catalytic partner into coordination capsules for efficient N-O bond cleavage and α-amino acid synthesis. This strategy includes the generation of NO adducts via glutathione-mediated NO binding and enzymatic NO activation via the formation of substrate-involved intermediates. The metal centers interact with the NO adducts, anodically shifting the redox potential up to -0.34 V_NHE. Under the optimized conditions, the enzymatic manifold facilitates an ammonia conversion rate of 182.16 μmol·h^-1·cm^-1 and a Faradaic efficiency (FE) of 87.1% with the lowest overpotential of -0.3 V_RHE, surpassing the performance of most reported electrocatalysts. When both the α-keto acid and the NO adduct were incorporated within the capsules, efficient electrocatalytic conversion of NO into amino acids was achieved with a high FE of 55.2%, providing an attractive way to elucidate enzyme-like activation dynamics.