Pulsed-potential electrolysis enhances nitrate reduction and C–N coupling upgrading

Converting harmful nitrate waste into value-added chemicals represents a promising alternative for achieving the electrocatalytic upgrading of NO3- and maintaining the global nitrogen balance. Nonetheless, improving the electrochemical performance and revealing reaction mechanisms still requires further investigation to meet the practical application requirements. Herein, we summarize the development of electrochemical NO3- reduction reaction (NO3RR) and C-N coupling reaction under pulsed-potential conditions. In the section on NO3RR, the electrocatalytic reaction systems for direct conversion of NO3- to NH3 are summarized. In the section on coupling, the C-N coupling reactions of NO3- with CO2 for urea synthesis, and with organic molecules for amino compounds synthesis are reviewed. The corresponding reaction mechanisms for different reaction systems are compared with the aid of theoretical calculations. Finally, the challenges and future perspectives are proposed. The pulsed-potential electrolysis for nitrate reduction not only increases the concentration of the local NO3-, key reactant, and intermediate species, but also restores the oxidation state of the active sites, providing guidance and reference for a nitrogen economy.