Electrocatalytic Nitrate Reduction on Metallic CoNi‐Terminated Catalyst with Industrial‐Level Current Density in Neutral Medium

Abstract

AbstractGreen ammonia synthesis through electrocatalytic nitrate reduction reaction (eNO3RR) can serve as an effective alternative to the traditional energy‐intensive Haber‐Bosch process. However, achieving high Faradaic efficiency (FE) at industrially relevant current density in neutral medium poses significant challenges in eNO3RR. Herein, with the guidance of theoretical calculation, a metallic CoNi‐terminated catalyst is successfully designed and constructed on copper foam, which achieves an ammonia FE of up to 100% under industrial‐level current density and very low overpotential (−0.15 V versus reversible hydrogen electrode) in a neutral medium. Multiple characterization results have confirmed that the maintained metal atom‐terminated surface through interaction with copper atoms plays a crucial role in reducing overpotential and achieving high current density. By constructing a homemade gas stripping and absorption device, the complete conversion process for high‐purity ammonium nitrate products is demonstrated, displaying the potential for practical application. This work suggests a sustainable and promising process toward directly converting nitrate‐containing pollutant solutions into practical nitrogen fertilizers.