The kinetics of enzymatic CO2 desorption reveal the potential of catalyzed solvent regeneration

Carbonic anhydrase (CA) speeds up the transfer of CO 2 into aqueous sorbents, sparking strong interest in enzyme-assisted carbon capture technologies. Many fundamental and applied studies have revealed CA's potential to accelerate CO 2 absorption and the underlying molecular mechanisms. However, CA-catalyzed desorption during solvent regeneration remains underexplored, particularly in quantitative analyses, leaving its benefits uncertain. Here, we present a systematic kinetic study of CA-catalyzed desorption of CO 2 captured in aqueous carbonate. We observed significant enzymatic acceleration of desorption, with enhancement factors comparable to those seen for absorption. This was important because it implied that enzyme catalysis could enable lower solvent regeneration temperatures. Specifically, we found that at 50°C, the rate of CO 2 desorption from bicarbonate supplemented with 5 µM thermostable CA matched the enzyme-free rate at 80°C. Additionally, enzyme-accelerationwas particularly noticeable in solvents that were partially loaded with CO 2 . These findings highlight that enzyme-catalyzed desorption could be a valuable approach for developing energy-efficient CO 2 scrubbing. Mechanistic analysis indicated that the enzyme's effect on desorption rates was confined to local catalysis near the gas-liquid interface, while reaction dynamics deeper in the aqueous bulk remained unaffected by CA.