Metal Organic Framework Porous Liquids for Integrated CO₂ Capture and Conversion

Integrated selective capture and conversion of CO₂ to high-value products is a highly energy-efficient and realistic strategy toward a carbon-neutral future. Inspired by nature, we have rationally designed type-III Porous Liquids (PLs) using carbonic anhydrase (CA) mimicking ZIF-8 and Good's buffer-based ionic liquid (IL) for highly efficient integrated selective capture and conversion of CO₂ under practical conditions. The PLs exhibit remarkable selectivity and uptake capacity for CO₂, among the highest reported for ZIF-8 based type-III PLs. The superior capture performance is ascribed to the molecular sieving effect and retention of high porosity in PL, further aided by the fluid media enabling both physi- and chemisorption storage pathways and high mass transport. The PLs catalyse CO₂ hydration, and the pore-encapsulated CO₂ and bicarbonate are in dynamic equilibrium. The captured CO₂ is subsequently converted to CaCO₃ in high yield. As against CA, the PLs are more tolerant to reaction conditions and showed better performance. Remarkably, PLs selectively capture and convert CO₂ from simulated flue gas (15% CO₂) and ambient air (0.04% CO₂), a highly desirable yet unexplored application. The study demonstrates PLs as a modular material for integrated CO₂ capture and catalytic conversion under practical conditions for a sustainable closed loop carbon economy.