We report the use of MIL-120 as a water-stable and cost-effective metal-organic framework (MOF) for selectively capturing CO₂ from wet flue gas. Synthesized using inexpensive and environmentally benign reagents in water, MIL-120 possesses one-dimensional pores decorated with hydroxyl-bridged Al(III) ions and benzene rings with an interstitial spacing of 4.78 Å....