Gas–liquid–solid reaction system for <scp>CO<sub>2</sub></scp> electroreduction to formate without using supporting electrolyte
Guillermo Díaz‐Sainz, Manuel Álvarez-Guerra, José Solla‐Gullón, Leticia García‐Cruz, Vicente Montiel, Ángel Irabien
Abstract
Abstract The use of bismuth‐based catalysts is promising for formate production by the electroreduction of CO 2 captured from waste streams. However, compared to the extensive research on catalysts, only a few studies have focused on electrochemical reactor performance. Hence, this work studied a continuous‐mode gas–liquid–solid reaction system for investigating CO 2 electroreduction to formate using Bi‐catalyst‐coated membrane electrodes as cathodes. The experimental setup was designed to analyze products obtained in both liquid and gas phases. The influence of relevant variables (e.g., temperature and input water flow) was analyzed, with the thickness of the liquid film formed over the cathode surface being a key parameter affecting system performance. Promising results, including a high formate concentration of 34 g/L with faradaic efficiency for formate of 72%, were achieved.