(173a) Electrochemical Carbon Dioxide Capture By Redox-Active Polymer

Electrochemical CO₂ capture for point sources in natural gas combined cycle (NGCC) power plants offers significant potential due to its high energy efficiency and adaptability across various application scenarios. However, electrochemically mediated carbon capture using quinones has been limited by the lack of reliable sorbents with high solubility, processability, stability against impurities, and—most critically—tolerance to O₂. In this study, we introduce a redox-active polymer integrated into a membrane-electrode-assembly-based system designed for efficient and stable CO₂ capture in O₂-containing environments. By manipulating electron distribution within the polymer structure, we suppress side reactions caused by O₂ exposure in flue gas. The resulting adsorbent demonstrates a low energy consumption (~4.8 GJ/ton), robust operational stability over 600 continuous hours, a high CO₂ capture ratio of up to 95%, and a coulombic efficiency of 45.7%. These performance metrics are attributed to the polymer’s tailored electronic properties that confer O₂ insensitivity, effectively mitigating energy losses from parasitic reactions. This work presents a feasible, cost-effective, and sustainable strategy for CO₂ capture in NGCC power plants.