Pulse-Driven Spatiotemporal Cooperativity in a Biomimetic Nanoreactor for Efficient Ammonia Electrosynthesis from Nitrate

Inspired by compartmentalization and dynamic regulation in cellular systems, we developed a spatiotemporal cooperative strategy by coupling a biomimetic compartmentalized nanoreactor (Co@C@Cu) with a dynamic pulsed potential regime, which integrates both spatial and temporal regulation of the electrochemical nitrate reduction reaction. Spatially, the Cu shell adsorbs and stepwise deoxygenates/hydrogenates NO₃^- derived intermediates; the Co core acts as an active H* pump; and a defective carbon interlayer forms a directional H* bridge and dynamic reservoir that mediates controlled H* spillover. This spatial arrangement ensures efficient intermediate conversion by locally controlling H* delivery and preventing the loss of key intermediates. Temporally, the alternating potential pulses decouple the deoxygenation and hydrogenation steps and dynamically optimize kinetics and control H* generation and consumption, thus balancing H* supply and demand in real time. In situ spectroscopy and theoretical simulations collectively confirmed the sequential deoxygenation/hydrogenation pathway and reveal the carbon interlayer's dual H*-mediating roles. The system achieves an outstanding NH₃ Faradaic efficiency of 98.0% and a yield of 15.8 mg h^-1 mg_cat^-1, surpassing several state-of-the-art catalysts under constant potential. This work establishes a generalizable spatiotemporal synergy strategy to regulate complex cascade reactions at the electrode-electrolyte interface and provides a promising paradigm for complex multistep electrocatalytic conversion.