Electrocatalytic Performance of MOF-Derived Cu-Co Bimetallic Electrode for Nitrate Reduction

The massive anthropogenic discharge of nitrate into aquatic environments disrupts the nitrogen cycle, posing threats to both ecosystems and human health. Electrocatalytic nitrate reduction to ammonia (ENRA) enables both nitrate removal and the production of high value-added NH3. Developing highly efficient and stable electrode materials, along with overcoming the rate-limiting step of nitrite accumulation, is crucial for enhancing the catalytic reduction of nitrate. In this study, by employing Cu as the core metal, a MOF-derived Cu-Co bimetallic catalytic electrode was fabricated as the cathode for converting nitrate to ammonia, while simultaneously resolving the issue of nitrite accumulation. The preparation parameters of the catalytic electrode were optimized, and the effects of current, initial pH, metal loading sequence, and other factors on ENRA performance were investigated. Experimental results demonstrate that the MOF-derived Cu-Co catalytic electrode achieved NO3− removal and NH4+ generation efficiencies of 94.26% and 90.58%, respectively, under a current density of 20 mA cm−2 for 150 min, with a marked suppression of NO2− accumulation. This study provides experimental evidence and technical support for the Cu-catalyzed electroreduction of nitrate to ammonia.