Microbubble-activated CO2 regeneration in scalable microporous liquids enabled by contact electrocatalysis.

Conventional carbon dioxide (CO2) capture systems are constrained by limited uptake capacity and energy-intensive regeneration. Here, we formulate a microporous carbon capture solution (MCCS) by dispersing a permanent-porosity framework (ZIF-67) in a liquid absorbent, coupling solvent-excluded physisorption with chemical uptake and boosting the CO2 capture capacity by ∼45%. Instead of bulk thermal stripping, we implement interfacial, microbubble-activated regeneration (MAR) with a decreased monoethanolamine (MEA) loss rate by ∼38%. Microbubble activation refreshes gas-liquid-solid contact to liberate 100% physiosorbed CO2, whereas microbubble-collapse events that mechanically trigger contact electrocatalysis (CEC), enabling interfacial hydroxyl radicals (•OH) that cleave carbamates under mild conditions and regenerates a substantial additional 37 to 55% of chemically absorbed CO2. Theoretical analyses reveal that •OH is the key species governing CO2 regeneration in the CEC-MAR process through oxidative carbon-nitrogen bond cleavage, followed by •H-assisted intermediate reduction to regenerate the amine. To approach engineering relevance, we realize kilogram-scale zeolitic imidazolate framework (ZIF) synthesis under ambient conditions using simple mechanical stirring, providing scalable MCCS inventory to enable (i) continuous delivery of high-purity CO2 (1437 millimoles over 200 minutes) from a laboratory-scale integrated system and (ii) direct electroreduction to carbon monoxide (CO) with a faradaic efficiency (FECO) of 51% without CO2 supply. More broadly, it establishes a porous-liquid, interfacial-regeneration paradigm that decouples capacity from stoichiometry and enables electrified, continuous CO2 capture, regeneration, and utilization under scalable, low-temperature conditions.