Chemically Modified\nHKUST-1(Cu) for Gas Adsorption\nand Separation: Mixed-Metal and Hierarchical Porosity

The archetypical metal–organic framework (MOF),\nHKUST-1,\nhas been systematically modified in both its organic and inorganic\nbuilding blocks to introduce diversity in the metal centers and create\ndefects within the network, achieving a variety of bimetallic hierarchical\nstructures. These modifications changed the affinity of the MOFs for\nacid gases. The introduction of bimetallic sites mostly affects CO<sub>2</sub> adsorption, while the hierarchical structure generates an\nincrease in SO<sub>2</sub> uptake capacity, allowing better performance\nin the separation of binary mixtures of these gases near room temperature.\nNotably, the synthesized HH-Cu<sub>100</sub> material exhibited an\nexceptionally high IAST SO<sub>2</sub>/CO<sub>2</sub> (10:90) selectivity\nof 3420 at 298 K, outperforming benchmark MOFs with open metal sites.