Membrane-separated electrodes enable high-rate low-energy electrochemical carbon capture
- Kaige Sun
- Mike Tebyetekerwa
- Hongxia Zhang
- Timothy T. Duignan
- Rizal Evans
- Lei Ge
- Yi Sun
- Yuhui Ge
- Zhuyuan Wang
- Chao Xing
- Jindi Yang
- Xiangkang Zeng
- Darren Martin
- Xiwang Zhang
2026-05-27
Electrochemical carbon dioxide (CO 2 ) capture using supercapacitive systems is a promising green technology but remains limited by low uptake rates and high energy requirement. Here, we present a membrane-integrated supercapacitor system that addresses these challenges by decoupling electrode environments with a cation exchange membrane. This configuration sustains high hydroxide concentration at the gas-facing negative electrode, generated through dynamic water dissociation within the electric double layer. The resulting localized alkaline interface enhances CO 2 capture by driving its conversion into (bi)carbonate species via a pH-swing mechanism. The system achieves a CO 2 uptake of up to 893 mmol/kg with a fast rate of 1281 mmol/kg/hour at −1.4 V under 20% CO 2 . Energy consumption as low as 32 kJ/mol is obtained at −0.8 V under 20% CO 2 together with a long lifetime over 200 hours at −1.0 V, 10% CO 2 . These findings establish a robust platform for electrochemical CO 2 capture and underscore the importance of localized chemical environments in supercapacitive swing adsorption.