Electrochemical conversion of CO₂ via C−X bond formation: recent progress and perspective

With the depletion of traditional energy sources and growing environmental concerns, it is becoming increasingly urgent to develop green, low-emission renewable energy technologies to replace fossil fuel-driven methods that emit carbon dioxide (CO₂). Currently, the electrochemical production of high-value-added chemicals and fuels from CO₂ has aroused great interest from scientists. However, to make full use of CO₂ for the preparation of chemicals, it is necessary to expand the range of electrosynthesis methods, in particular by expanding reaction pathways through the reaction of CO₂ with different substrates. In general, CO₂ can form new covalent bonds with substrate molecules through the formation of C−X bonds, including C−H, C−C, C−N, C−O, and C−S bonds, which would expand the range of possible products by diversifying the reaction pathway. In this review, we focus on the research progress in electrochemical conversion of CO₂ through C−X bond formation. We start by examining fundamentals of the reactions and summarizing the reaction modes. Next, we discuss the electrosynthesis of C−X bonds (C−H, C−C, C−N, C−O, C−S) using CO₂ and different substrate molecules. Finally, (i) strategies for the design and activity optimization of catalyst materials and (ii) the future development of forming five types of bonds from CO₂ and small molecules are discussed, along with an outlook on their future research prospects.