Abstract
The direct electrochemical conversion of carbon capture solutions into multi-carbon (C(2+)) products offers a sustainable alternative to decarbonize chemical manufacturing, bypassing energy-intensive CO(2) regeneration and purification steps in conventional CO(2) conversion technologies. However, it faces persistent challenges in selectivity and operational stability. Here, this study demonstrates that bicarbonate, an inherent component of carbon capture media, stabilizes Cu(2)O/Cu heterointerfaces in laminate oxide-derived Cu (LOD-Cu) catalysts, enabling long-term ethylene (C(2)H(4)) production. In a zero-gap membrane electrode assembly (MEA) electrolyzer, bicarbonate electrolytes support a C(2)H(4) Faradaic efficiency of ≈54% at 200 mA cm(-2) over 80 h of continuous operation. In situ spectroscopic analysis reveals that bicarbonate mitigates the full reduction of Cu(2)O, preserving interfacial motifs that are critical for C─C coupling. This work uncovers bicarbonate's role in stabilizing Cu(2)O/Cu heterointerfaces, thereby preserving catalytically active motifs and enabling efficient, durable C(2)H(4) production. It provides a practical strategy for integrating carbon capture with renewable C(2)H(4) chemical synthesis.