Electrocatalytic CO₂ Reduction to C₂₊ Products in Flow Cells

Electrocatalytic CO₂ reduction into value-added fuels and chemicals by renewable electric energy is one of the important strategies to address global energy shortage and carbon emission. Though the classical H-type electrolytic cell can quickly screen high-efficiency catalysts, the low current density and limited CO₂ mass transfer process essentially impede its industrial applications. The electrolytic cells based on electrolyte flow system (flow cells) have shown great potential for industrial devices, due to higher current density, improved local CO₂ concentration, and better mass transfer efficiency. The design and optimization of flow cells are of great significance to further accelerate the industrialization of electrocatalytic CO₂ reduction reaction (CO₂ RR). In this review, the progress of flow cells for CO₂ RR to C₂₊ products is concerned. Firstly, the main events in the development of the flow cells for CO₂ RR are outlined. Second, the main design principles of CO₂ RR to C₂₊ products, the architectures, and types of flow cells are summarized. Third, the main strategies for optimizing flow cells to generate C₂₊ products are reviewed in detail, including cathode, anode, ion exchange membrane, and electrolyte. Finally, the preliminary attempts, challenges, and the research prospects of flow cells for industrial CO₂ RR toward C₂₊ products are discussed.