Dynamically Restructuring Nanoporous Cu–Co Electrocatalyst for Efficient Nitrate Electroreduction to Ammonia

The electrochemical nitrate (NO 3 – ) reduction reaction (NITRR) to ammonia (NH 3 ) offers an environmentally friendly alternative for NH 3 synthesis but suffers from limited NH 3 yield and low Faradaic efficiency (FE) due to the sluggish kinetics of the hydrogenation process. Herein, nanoporous Cu/CoOOH heterostructure is reported as an efficient electrocatalyst for NITRR. The catalyst achieves a high NH 3 yield rate of 275.9 μmol h –1 cm –2 (689.8 mmol h –1 g cat –1 ) and 836.8 μmol h –1 cm –2 (2092.0 mmol h –1 g cat –1 ), with corresponding FE values of 85.3 and 91.5% in 200 and 1400 ppm of NO 3 – -N electrolyte, respectively. In situ Raman spectra reveal that the Cu/CoOOH heterostructure is derived from synergistic chemical/electrochemical redox reaction between NO 3 – and the CuCo alloy during the NITRR process. Theoretical simulations indicate that Cu/CoOOH exhibits enhanced *NO 2 affinity and reduces the energy barrier in the rate-determining *NO 2 H formation step, effectively facilitating NO 3 – reduction to NH 3 .