Chemically Modified HKUST-1(Cu) for Gas Adsorption and Separation: Mixed-Metal and Hierarchical Porosity.

The archetypical metal-organic framework (MOF), HKUST-1, has been systematically modified in both its organic and inorganic building blocks to introduce diversity in the metal centers and create defects within the network, achieving a variety of bimetallic hierarchical structures. These modifications changed the affinity of the MOFs for acid gases. The introduction of bimetallic sites mostly affects CO adsorption, while the hierarchical structure generates an increase in SO uptake capacity, allowing better performance in the separation of binary mixtures of these gases near room temperature. Notably, the synthesized HH-Cu material exhibited an exceptionally high IAST SO/CO (10:90) selectivity of 3420 at 298 K, outperforming benchmark MOFs with open metal sites.