Critical Assessment of Pulsed Current Strategies for Electrochemical CO ₂ Reduction in Gas Diffusion Electrode Flow Cells

ABSTRACT

The electrochemical reduction of () to multi‐carbon (C ₂₊ ) products holds great promise for sustainable chemical and fuel production. While pulsed electrolysis has been reported to enhance selectivity and suppress hydrogen evolution in laboratory scale systems by modulating local reaction environments and surface states, its applicability to gas‐fed flow reactors at industrially relevant current densities remains unclear. In this study, we present a targeted evaluation of pulsed current strategies, including symmetric, asymmetric and anodic pulse profiles, for the in a gas‐fed flow cell equipped with CuO‐based gas diffusion electrodes (GDEs). The influence of pulse parameters on Faradaic efficiencies, product distribution, operational stability and energy efficiency is evaluated at high current densities. Within the investigated pulse‐duration range of 0.05–1 s and the selected current profiles, pulsed operation did not enhance C ₂₊ selectivity. Instead, longer pulse durations promoted CO formation. Symmetric pulsing yielded results comparable to steady‐state operation, whereas asymmetric pulsing induced significant salt precipitation within the GDE, limiting transport and increasing hydrogen evolution. The application of an anodic current did not mitigate these effects and further suppressed carbon‐based product formation. These results show that the investigated pulsed electrolysis strategies established in H‐type cells did not translate directly to the gas‐fed flow reactor under the studied conditions. Instead, transport limitations and precipitation phenomena emerged as dominant constraints, emphasizing the need for pulse strategies specifically adapted to scalable electrolysis systems.