Breakthrough Zn(II) Catalyst for Direct Air Capture Employing CO ₂ Hydration

Direct air capture (DAC) represents a vital technology for atmospheric CO2 remediation, but few studies have tested catalysts at dilute atmospheric CO2 concentrations. Inspired by the carbonic anhydrase metalloenzyme, we report a catalytic DAC strategy employing robust zinc(II) enzyme mimics that enable efficient CO2 sequestration pathways. A catalyst-mediated CO2 hydration cycle in aqueous sorbents facilitates accelerated capture from dilute atmospheric air, thereby addressing the kinetic limitations observed in carbonate-based systems. Our developed complexes [ZnC1] and [ZnC2] enhance capture rates up to 2-fold at millimolar concentrations and improve the CO2 mass transfer by 40–60% in 1 M K2CO3 sorbent under ambient conditions. These bench-stable, earth-abundant zinc catalysts operate effectively under dilute CO2 concentrations, overcoming the kinetic limitations of conventional carbonate-based sorbents. Mechanistic studies support a biomimetic catalytic cycle that facilitates rapid CO2 conversion, demonstrating that a catalyst-assisted DAC can enable energy-efficient, scalable carbon capture technologies.