Microfluidic reactor for the electrochemical reduction of carbon dioxide: The effect of pH

This article reports the development and characterization of a microfluidic reactor for the electrochemical reduction of carbon dioxide. The use of gas diffusion electrodes enables better control of the three-phase interface where the reactions take place. Furthermore, the versatility of the microfluidic reactor enables rapid evaluation of catalysts under different operating conditions. Several catalysts as well as the effects of electrolyte pH on reactor efficiency for reduction of CO₂ to formic acid were tested. Operating at acidic pH resulted in a significant increase in performance: faradaic and energetic efficiencies of 89 and 45%, respectively, and current density of ∼100 mA/ cm².