Vector‐Reversal Strategy: Redirecting In Situ Generated CO ₂ for Low‐Voltage Bicarbonate Reduction

ABSTRACT The direct electrochemical reduction of liquid CO ₂ capture media, such as bicarbonate, presents a viable pathway to enhance economic competitiveness by obviating the need for CO ₂ desorption. However, a critical challenge in bicarbonate reduction systems arises from the in situ generation of CO ₂ at the membrane interface, which forces CO ₂ and ions to share transport pathways, inevitably leading to elevated cell voltages. Herein, we suggest a CO ₂ vector‐reversal strategy utilizing a perforated architecture to effectively mitigate the issue of high cell polarization by spatially decoupling these transport pathways. At a high current density of 400 mA cm ⁻² , the perforated configuration (PE+PI) maintained a drastically lower and stable cell voltage of 3.65 V, whereas the conventional non‐perforated system (NPE+NPI) experienced severe polarization, surging to 5.12 V. Furthermore, this optimized diffusion environment led to a notable improvement in Faradaic efficiency for CO production (> 10%) and effectively prevented the surge in ionic resistance even under vigorous gas evolution. The optimized system also demonstrated excellent long‐term operational reliability without structural deterioration for 16 h at 50 mA cm ⁻² . Consequently, this vector‐reversal strategy offers a highly practical engineering framework for the future advancement of high‐efficiency bicarbonate reduction systems.