Electrochemical Oxidation Strategy for Integrated CO₂ Capture and Conversion

The sequential CO₂ capture and conversion suffer from substantial energy penalties associated with CO₂ recovery. While direct electrochemical (bi)carbonate reduction circumvents this energy-intensive step, it still faces several limitations, including low carbon utilization efficiency, cumbersome product separation, and reliance on the anodic oxygen evolution reaction─a process hampered by slow kinetics and limited economic value. Herein, we present an electrochemical oxidation strategy that directly employs a CO₂-captured NaOH solution─rich in (bi)carbonate ions─as the electrolyte. In this system, (bi)carbonate-mediated two-electron water oxidation reaction takes place, enabling the in situ generation of H₂O₂. Following electrolysis, Na₂CO₃·1.5H₂O₂, a solid crystalline adduct of Na₂CO₃ and H₂O₂, was readily separated from the electrolyte, thereby fixing CO₂ into a storable and value-added product. This integrated approach eliminates the need for energy-intensive CO₂ recovery, offering a streamlined route to convert captured CO₂ into easily isolable, high-value chemicals.