First-principles study of carbon capture and storage properties of porous MnO ₂ octahedral molecular sieve OMS-5

Based on the experimentally determined framework structure of porous MnO ₂ octahedral molecular sieve (OMS)-5, we used density functional theory-based calculations to evaluate the effect of Na ⁺ cation on pore dimensionality and structural stability, and the interaction between CO ₂ and OMS-5. We quantified the formation energy of one CO ₂ /unit tunnel and two CO ₂ /unit tunnel, and projected the electronic density of states on the OMS-5 framework, CO ₂ molecules, and Na ⁺ cations to reveal their individual contributions and bonding nature. Partial charge densities were also calculated to investigate CO ₂ adsorption behavior in the OMS-5. Our studies predict the initial stage and driving force for the adsorption of CO ₂ in the OMS-5, guiding the OMS material design for carbon capture and storage applications.