Synergistic effects of metallic IrCo for promoted nitrate reduction in industrial-relevant wastewater level

Electrochemically converting nitrate in wastewater as underleveraged nitrogen source into ammonia is a sustainable strategy for simultaneously valorizing wastewater and alleviating environmental contamination. However, it remains challenging for conversion of environmentally relevant nitrate in complex environments. Herein, a versatile IrCo alloy on N-doping carbon is presented with 93.3 % Faradaic efficiency and 21 mg h −1 mg cat −1 ammonia yield. Furthermore, we first achieve nearly complete nitrate removal (>99 %) under different pH conditions, from typical industrial wastewater concentrations (40 mM) to a drinking water standard (NO 3 – -N < 5 μg ml −1 ). Afterwards, high-value struvite (NH 4 MgPO 4 ·6H 2 O) products were obtained from the produced ammonia on a gram scale. DFT calculation reveals that optimized Co structure modulates the adsorption of intermediate *NH and facilitates further hydrogenation steps (*NH → *NH 2 ), whereas, limited on isolate Co sites due to weak H 2 O affinity and over-strong *H adsorption. The work gives effective insights into progressive ammonia production and environmental wastewater utilization.