Electrocatalytic and Photocatalytic C─N Coupling From Small Molecules

Electrocatalytic/photocatalytic C─N coupling from small carboncontaining (such as CO₂ and CH₃OH) and nitrogen-containing species (such as N₂, NO₃ ^-, and NH₃) enables the synthesis of value-added organonitrogen compounds, including urea, amides, and amino acids. This approach, ideally driven by renewable energy, holds great promise for sustainable developments and has thus been attracting increasing research interest in recent years. To enhance the C─N coupling under mild reaction conditions, it is necessary to activate different substrate molecules effectively and balance the adsorption and desorption of various C- and N-containing intermediates and/or radicals, thereby realizing different value-added organonitrogen compounds. In this review, the recent advances in electrocatalytic/photocatalytic C─N coupling reactions targeting those three types of products, i.e., urea, amides, and amino acids is aimed to summarized. The rational designs of active sites for synergistic catalysis are discussed, including their types, compositions, spatial arrangements, crystal facets, heterostructures, and local environments. Different reactant molecules and catalytic mechanisms for the electrocatalytic/photocatalytic C─N coupling reactions, as well as the methods of C─N coupling products detection, are also described. Finally, the existing challenges in this field are summarized, and the potential research perspectives are also proposed.