Investigation of cell components for increasing ethylene production in integrated CO2 electrolysis

Abstract

Sustainable chemical manufacturing relies on closing the carbon cycle by transforming CO2 into useful products such as ethylene. Integrated CO2 electrolysis enables direct use of CO2‐rich absorbents, whereby efficient operation requires optimization of process conditions and cell design. This publication investigates the influence of flow field design, gas diffusion layer properties, catalyst loading, gas diffusion electrode compression, and membrane thickness on ethylene formation in a zero‐gap membrane electrode assembly electrolyzer using CO2‐saturated potassium bicarbonate which is the CO2‐loaded absorbent in the commercial potassium carbonate CO2 scrubbing process. The results show that a flat, uniformly thin copper layer about 2 µm‐thick, placed next to a thin 20 µm anion exchange membrane, creates an enhancing microenvironment for C2+ product formation with a maximum FE of 31% to ethylene at a current density of 50 mA cm-2 and a cell voltage of 5.2 V. These findings highlight the critical role of catalyst layer architecture and membrane selection in the effective conversion of CO2 to C2+ products. By focusing on the interplay between cell components and local reaction environments, this work advances the design of integrated CO2 electrolyzers for efficient ethylene production, supporting the development of scalable, and sustainable carbon utilization.