Nature – Jin et al. (2025): Direct air capture of CO₂ in an electrochemical hybrid flow cell with a spatially isolated phenazine electrode
Xinyu Jin, Shijian Jin, Lu Li, Roy G. Gordon, Pan Wang, Michael J. Aziz and Yunlong Ji, IN: Nature Energy, https://doi.org/10.1038/s41560-025-01836-3
CO₂ capture based on a pH swing driven electrically through the reversible proton-coupled electron transfer of organic molecules could be powered entirely by clean electricity. A major technical challenge is the reversible chemical oxidation of the reduced organics by atmospheric O₂, which can lower energy efficiency and capture capacity. Here the authors report the development of a hybrid phenazine flow cell system that uses a pH-swing direct air capture (DAC) process, utilizing redox-active cyclic poly(phenazine sulfide) fabricated solid electrodes. The system maintains a separation between the air and the O₂-sensitive reduced phenazine, enabling stable and effective CO₂ capture from gas mixtures containing O₂.