Cascade CO ₍₂₎ electroreduction and downstream reactions for carbon product upgrading

Using renewable electricity to electrochemically reduce CO₂/CO (eCO₍₂₎R) into value-added chemicals offers a promising pathway for sustainable fuel production. Although advances in catalyst design and system engineering have enabled CO₂/CO electroreduction to achieve high current densities for producing hydrocarbons and oxygenates, the products remain largely limited to small carbon molecules (C₁–C₃). Recently, significant progress has been made in cascading eCO₍₂₎R and downstream reactions to synthesize a broader spectrum of polymeric or higher-value carbon products. However, comprehensive summaries and perspectives on these cascade systems are still scarce in the eCO₍₂₎R literature. This review systematically summarizes recent developments in cascade eCO₍₂₎R and downstream conversion. The advantages brought by integrating eCO₍₂₎R with additional reaction steps are analyzed, followed by the discussion of representative systems that couple eCO₍₂₎R with thermocatalytic, biological, and electrochemical processes. Finally, the key challenges facing this emerging field are highlighted, along with perspectives on future research directions.