Scale‐up of electrochemical flow cell towards industrial CO<sub>2</sub> reduction to potassium formate
Arthur G. Fink, Fabiola Navarro‐Pardo, Jason R. Tavares, Ulrich Legrand
Abstract
Abstract The CO 2 electroreduction reaction (CO2RR) presents a pathway to decarbonize the manufacturing industry by using clean electricity and CO 2 as feedstocks instead of relying on fossil fuels. Although known for over 100 years, this technology has yet only been developed at bench‐top scale (1–100 cm 2 ). In this manuscript, we report CO 2 electroreduction to potassium formate (HCOOK) in a stack of two 1526‐cm 2 three‐compartments electrochemical cells with gas diffusion electrode (GDE) cathodes. In this stack, we achieved over 60 % current selectivity towards HCOOK at current densities of 200 mA cm −2 and under cell voltages of ~4.0 V. We reached these performance metrics by tuning electrolyte composition and cell architecture. We also show that a minimum of +10‐14 kPa of pressure difference must be applied between gaseous and catholyte compartments to enable the CO2RR to take place. We emphasize the challenges associated with scaling‐up a CO 2 electrochemical cell, specifically by demonstrating that optimal operation parameters are strongly correlated to cell architecture. This study demonstrates the feasibility of developing CO2RR electrochemical cells to an industrial scale.