Efficient Direct Air Capture in Industrial Cooling Towers Mediated by Electrochemical CO₂ Release

Direct air capture (DAC) is a promising technology for mitigating global climate change but suffers from low efficiency, small scale, and high cost due to the dilute atmospheric CO₂, limited size of air contactors, and heat-driven CO₂ release. Here, we propose combining DAC with widely used industrial cooling towers to extract CO₂ from the air and using electrolysis to release the captured CO₂ at room temperature. We first prepare a buffered absorbent solution consisting of sodium glycinate, glycine, and sodium chloride for effective CO₂ capture from the air, solving the incompatibility problem of the cooling towers with conventional absorbents. Next, we employ a three-chamber electrolyzer for efficient release (≥95 %) of the captured CO₂ with high purity (≥98 %) by constant current electrolysis at room temperature, bypassing the conventional energy-intensive heating process. The entire DAC system can operate stably for multiple cycles, and the mechanism for consecutive CO₂ capture and release is uncovered. This work reveals the great potential of running DAC in industrial cooling towers coupled with electrochemically-driven CO₂ release, opening up new avenues for curbing the increasingly severe climate change.