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

Capture and conversion of CO 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 reduction (COR) cell to capture and convert CO 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 at an electrochemical energy consumption of 155.4 kJ mol or 0.98 kWh kg of CO and a CO capture efficiency of 71%. The direct coupled, vapor-fed COR cell yields a total Faradaic efficiency of up to 95% for electrochemical CO reduction to CO. The proof-of-concept system provides a unique technological pathway for CO capture and conversion from oceanwater with only electrochemical processes.