A combinatorial approach towards water-stable metal-organic frameworks for highly efficient carbon dioxide separation.

A library of 20 UiO-66-derived metal-organic frameworks (MOFs) is synthesized in a combinatorial approach involving mixed ligand copolymerization and two post-synthetic modifications (PSMs) in tandem. Mixed ligand co-polymerization of benzene-1,4-dicarboxylic acid (BDC) and sodium 2-sulfoterephthalate (SS-BDC) with zirconium tetrachloride (ZrCl4) was used to prepare 5 groups of MOFs with the same UiO-66 topology but differing amounts of sulfate groups. These MOFs exhibit excellent water stabilities in a pH range of 1 to 12, together with high CO2 uptake capacities and selectivities.