Cascade Catalysis for CO2 Upgrading to Long-Chain Products.

Cascade catalytic conversion of CO2 has recently emerged as a transformative strategy for multilevel CO2 valorization. By integration of electrocatalytic CO2 reduction with thermocatalytic and/or biocatalytic processes, this approach enables stepwise construction of complex products from simple carbon feedstocks. The electrocatalytic stage supplies key intermediates or upstream products such as CO, formate, formaldehyde, or ethanol, which can be further converted into value-added multicarbon products including sugars, polymers, and other fine chemicals through downstream coupling. Recent demonstrations, ranging from CO2-to-sugar and CO2-to-polyketone conversions to artificial CO2-to-polymer biocatalytic pathways, have demonstrated the great potential of cascade strategies in bridging electro-, thermo-, and biochemistry. This Outlook discusses recent progress in electrochemical cascade CO2 conversion and outlines the key design goals for this field, including full-cascade performances, coupled catalyst-reaction optimizations, mechanistic understanding across complex interfaces, and integrated reactor architectures.