Gram-Scale Ammonia Synthesis via Electrochemical Nitrate Reduction Using Enzyme-Inspired Dual-Atomic Cu Catalyst

The potential application prospects of green electricity-driven electrocatalytic nitrate reduction (NO₃RR) technology for the production of valuable ammonia have garnered widespread attention. However, designing electrocatalysts with remarkable activity and stability for the NO₃RR to realize gram-level ammonia production remains a significant hurdle in terms of practical application. In nature, the synergistic effect of the dual-site copper of nitrite reductase promotes the substrate adsorption and protonation, achieving efficient conversion of nitrite. Herein, enzyme-inspired Cu dual-atomic sites are constructed on polymeric carbon nitride (PCN-Cu-DAC). Systematic investigations indicate the dual-atomic Cu sites in the catalyst exhibit stronger proton transfer and synergistic nitrate adsorption interaction, thereby reducing the energy barrier for *NO protonation. Studies have shown that the PCN-Cu-DAC catalyst presents a remarkable ammonia (NH₃) yield (467 mg h^-1 mg^-1 cat. and 102 mg h^-1 cm^-2) and achieves 11 g d^-1 NH₃ yield at 6 A of current for 360 h. This work demonstrates the concept of mimicking natural nitrite reductase toward the continuous reduction of nitrate wastewater and promotes the production of NH₃.