A Perspective on Copper-Based Catalysts for Nitrate-to-Ammonia Electrochemical Reduction

Nitrate widely exists in industrial wastewater and polluted groundwater as an environmental pollutant, resulting in severe environmental risks. The nitrate-to-ammonia electrochemical reduction reaction (NO3RR) is recognized as the most compelling solution for reducing environmental pollutants (NO) into the value-added product ammonia (NH3) due to compatibility with renewable energy. In recent years, copper-based electrocatalysts have emerged as one of the most promising methods for NO3RR owing to their relatively high catalytic activity and cost-effectiveness, also minimizing environmental impact. From this perspective, we summarize the function of copper-based catalysts in NO3RR. We also provide an overview of the current achievements of different copper-based catalysts for NO3RR. Furthermore, this perspective raises future challenges in designing highly effective and long-term stable catalysts for industrial-scale applications as well as in clarifying reaction pathways by theoretical and experimental characterization tools.