Tandem engineering for CO₂ electrolysis toward multicarbon products

Electrocatalysis of CO₂ toward multicarbon (C₂₊) products have multifaceted applications in the energy and chemical industries, offers an attractive route to mitigate carbon emissions and abate the depletion of fossil fuels. However, the productivity of CO₂-to-C₂₊ products suffers from a low selectivity and reaction rate owing to the difficulty in C–C coupling and the multiple electron-proton transfer steps. Recently, numerous tandem catalysts have been developed to improve the selectivity and formation rate of CO₂-to-C₂₊ products via coupled multiple reaction steps, exhibiting high industrial practicability. This review summarized recent progresses in the formation of C₂₊ products from CO₂ electrolysis on tandem catalysts. In this review, we highlight the cooperative regulation strategy of tandem catalysts formed by introducing different types of new components and reveal the relationships between *CO intermediate mass transport and the selectivity of C₂₊ products. Moreover, theoretical insight into the tandem catalytic mechanisms underlying the enhanced C₂₊ selectivity is also provided. Finally, the remaining challenges and opportunities for the electrocatalytic CO₂ toward C₂₊ products are discussed.