Electrocatalytic reactions involving aqueous nitrate and nitrite

Electrocatalytic upgrading of aqueous nitrate ( \({\rm{NO}}_{3}^{-}\) ) and nitrite ( \({\rm{NO}}_{2}^{-}\) ) represents a sustainable and increasingly important approach for producing valuable nitrogenous chemicals from abundant and hazardous feedstocks. Recent advances have demonstrated the ability to selectively convert \({\rm{NO}}_{3}^{-}\) / \({\rm{NO}}_{2}^{-}\) into products such as inorganic nitrogenous species including ammonia (NH 3 ), hydroxylamine (NH 2 OH), hydrazine (N 2 H 4 ) and organonitrogen compounds (e.g., urea, oximes and amines). However, the absence of standardized protocols has hindered reproducibility and cross-laboratory comparisons. Herein, we present a comprehensive protocol for aqueous \({\rm{NO}}_{3}^{-}/{\rm{NO}}_{2}^{-}\) -involved electrocatalytic reactions. Our protocol includes electrode preparation, electrolyzer assembly, electrolysis, product quantification and purification, in situ characterization and technoeconomic analysis. The protocol includes essential safety guidelines for toxic intermediate handling. Moreover, it remains adaptable to different levels of experimental capability. This protocol is suitable for initial screenings and mechanistic investigations spanning small-scale reactors (<30 ml) to liter-level systems and takes ~2 weeks to complete. This work is designed for researchers in green and sustainable chemistry, electrocatalysis, nanotechnology and environmental science and aims to establish reproducible workflows that accelerate the development of electrochemical \({\rm{NO}}_{3}^{-}/{\rm{NO}}_{2}^{-}\) upgrading strategies. More importantly, we hope that the protocol can motivate researchers to design catalytic strategies to upgrade renewable chemical sources beyond \({\rm{NO}}_{3}^{-}/{\rm{NO}}_{2}^{-}\) .