A Scalable Robust Microporous Al-MOF for Post-Combustion Carbon Capture

Herein, a robust microporous aluminum tetracarboxylate framework, MIL-120(Al)-AP, (MIL, AP: Institute Lavoisier and Ambient Pressure synthesis, respectively) is reported, which exhibits high CO₂ uptake (1.9 mmol g^-1 at 0.1 bar, 298 K). In situ Synchrotron X-ray diffraction measurements together with Monte Carlo simulations reveal that this structure offers a favorable CO₂ capture configuration with the pores being decorated with a high density of µ₂-OH groups and accessible aromatic rings. Meanwhile, based on calculations and experimental evidence, moderate host-guest interactions Q_st (CO₂) value of MIL-120(Al)-AP (-40 kJ mol^-1) is deduced, suggesting a relatively low energy penalty for full regeneration. Moreover, an environmentally friendly ambient pressure green route, relying on inexpensive raw materials, is developed to prepare MIL-120(Al)-AP at the kilogram scale with a high yield while the Metal- Organic Framework (MOF) is further shaped with inorganic binders as millimeter-sized mechanically stable beads. First evidences of its efficient CO₂/N₂ separation ability are validated by breakthrough experiments while operando IR experiments indicate a kinetically favorable CO₂ adsorption over water. Finally, a techno-economic analysis gives an estimated production cost of ≈ 13 $ kg^-1, significantly lower than for other benchmark MOFs. These advancements make MIL-120(Al)-AP an excellent candidate as an adsorbent for industrial-scale CO₂ capture processes.