A Tailor-Made Interpenetrated MOF with Exceptional Carbon-Capture Performance from Flue Gas

Summary

Metal-organic frameworks (MOFs) have attracted significant attention as sorbents for low-energy separation of CO₂ from flue gas. Herein, we report the use of an interpenetration approach to developing a fluorinated MOF with the appropriate pore system to enable the efficient capture of CO₂ from flue gas at 298 K. The MOF, dptz-CuTiF₆, exhibits excellent volumetric and gravimetric CO₂ uptakes at 10% CO₂ and 298 K, which are superior to those of the reference aqueous amine technique, with significantly lower energy input for regeneration (38 kJ mol⁻¹ versus 105 kJ mol⁻¹). In cyclic breakthrough experiments, dptz-CuTiF₆ achieves complete CO₂ desorption at 298 K under inert gas purging. Single-crystal X-ray diffraction studies demonstrate that the exceptional CO₂ adsorption capacity, moderate CO₂ heat of adsorption, and high CO₂-N₂ selectivity are due to the optimal packing of the CO₂ molecules within the MOF as well as the favorable thermodynamics and kinetics from cooperative host-guest interactions.