Carbonate-Based Zeolitic Imidazolate Framework for Highly Selective CO₂ Capture

In this study, we report the formation of a new crystal structure, ZIF-CO₃-1, which results from the reaction of Zn²⁺, 2-methylimidazole, and carbonate. ZIF-CO₃-1 can be synthesized solvothermally in N,N-dimethylformamide (DMF)/water (H₂O) or by utilizing of CO₂ gas at various temperatures in DMF/H₂O or H₂O. This reaction selectively consumes CO₂ because CO₂ is incorporated in the ZIF as carbonate. CO₂ can be quantitatively released by acidifying the ZIF. Powder X-ray diffraction, single-crystal X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, elemental analysis, and thermogravimetric analysis were used to characterize the ZIF structure. ZIF-CO₃-1 (chemical formula C₉H₁₀N₄O₃Zn₂), crystallizes in the orthorhombic crystal system with noncentrosymmetric space group Pba2.