Promoting the Electrochemical Reduction of Carbon Dioxide by a Specially Designed Biomimetic Electrochemical Cell

To overcome the difficulties arising from the slow dissolution of CO2 and the depletion of electrolyte in the anodic area, so as to obtain higher space time yield for electrochemical reduction of carbon dioxide to formic acid (ERCO2F), we have designed a biomimetic electrochemical cell (BEC). The BEC has two gas diffusion electrodes separated by a flowing electrolyte regulator, which forces the electrolyte to flow from one electrode to the other, and a formic acid separator in the upstream of the circulating electrolyte. Here, the cathode is a piece of Sn-electroplated Cu foam, and the anode is a piece of pure Ni foam. The results show that the space time yield is 290 μmol h–1 cm–2 at −1.8 V vs Ag/AgCl, respectively, while the Faradaic efficiency remains at 92%, which is 2 times of that in an undivided electrochemical cell (143 μmol h–1 cm–2 at −1.8 V vs Ag/AgCl). Consequently, the BEC successfully speeds up the ERCO2F.