A direct coupled electrochemical system for capture and conversion of CO2 from oceanwater

Capture and conversion of CO 2 from oceanwater can lead to net-negative emissions and can provide carbon source for synthetic fuels and chemical feedstocks at the gigaton per year scale. Here, we report a direct coupled, proof-of-concept electrochemical system that uses a bipolar membrane electrodialysis (BPMED) cell and a vapor-fed CO 2 reduction (CO 2 R) cell to capture and convert CO 2 from oceanwater. The BPMED cell replaces the commonly used water-splitting reaction with one-electron, reversible redox couples at the electrodes and demonstrates the ability to capture CO 2 at an electrochemical energy consumption of 155.4 kJ mol −1 or 0.98 kWh kg −1 of CO 2 and a CO 2 capture efficiency of 71%. The direct coupled, vapor-fed CO 2 R cell yields a total Faradaic efficiency of up to 95% for electrochemical CO 2 reduction to CO. The proof-of-concept system provides a unique technological pathway for CO 2 capture and conversion from oceanwater with only electrochemical processes. Isolating CO 2 to use in electrochemical CO 2 reduction systems is an ongoing issue. Here, the authors present a proof-of-concept integrated system combining a bipolar membrane electrodialysis cell with a vapor-fed CO 2 reduction cell for capture and conversion of CO 2 from oceanwater.