Boosting the Productivity of Electrochemical CO₂ Reduction to Multi-Carbon Products by Enhancing CO₂ Diffusion through a Porous Organic Cage

Electroreduction of CO₂ into valuable fuels and feedstocks offers a promising way for CO₂ utilization. However, the commercialization is limited by the low productivity. Here, we report a strategy to enhance the productivity of CO₂ electroreduction by improving diffusion of CO₂ to the surface of catalysts using porous organic cages (POCs) as an additive. It was noted that the Faradaic efficiency (FE) of C2+ products could reach 76.1 % with a current density of 1.7 A cm⁻² when Cu-nanorod(nr)/CC3 (one of the POCs) was used, which were much higher than that using Cu-nr. Detailed studies demonstrated that the hydrophobic pores of CC3 can adsorb a large amount of CO₂ for the reaction, and the diffusion of CO₂ in the CC3 to the nanocatalyst surface is easier than that in the liquid electrolyte. Thus, more CO₂ molecules make contact with the nanocatalysts in the presence of CC3, enhancing CO₂ reduction and inhibiting generation of H₂.