Porous Zr₆L₃ Metallocage with Synergetic Binding Centers for CO₂

Coordination-driven assembly has been widely successful in the synthesis of metallocages and used for many applications, such as catalysis. However, studies on CO₂ adsorption with metallocages have been rarely conducted, compared to other well-known cage-type materials, such as porous organic cages. In this study, a rational choice of ligand and metal led to the synthesis of a Zr₆L₃-type metallocage, exhibiting exceptional CO₂ adsorption properties. CO₂ adsorption experiments revealed that the metallocage shows highly selective adsorption of CO₂ over N₂ with high CO₂ binding energy. Density functional theory calculations uncovered the origin of this exceptional affinity for CO₂ over N₂.