Conversion of nitrogenous small molecules into value-added chemicals by building N–C bonds

The conversion of abundant nitrogen into various nitrogen-containing chemicals has high academic and economic values. Traditional artificial nitrogen cycle conversion requires high temperature, high pressure, and high energy consumption reaction conditions, which does not meet the requirements of energy conservation, emission reduction, and greenhouse gas control. At present, researchers in this field have developed several artificial nitrogen cycle reaction paths, including electrochemical conversion of inorganic nitrogen-containing small molecules into value-added chemicals. This review mainly focuses on electrochemical NC bond formation reactions, which cover CO2 reduction, flue gas treatment, and biomass upgrading. Specifically, the electrochemical synthesis of amines, amides, urea, amino acids, and other organic nitrogen compounds from CO2, biomass, and their derivatives are summarized. Based on the types of reactions/reactants, catalysts, and basic mechanisms, sustainable synthesis approaches of different products are classified. Additionally, to expand the range of reactions for electrochemical upgrading of inorganic nitrogen small molecules, this review also summarizes the research on electrochemical NN and NS bond formation with high economic values. This review aims to comprehensively outline the electrochemical reactions for generating high-value products from inorganic nitrogen small molecules, and presents current challenges and future development directions.