First-principles Studies of Carbon Dioxide Adsorption in Cryptomelane/Hollandite-Type Manganese Dioxide
Lan Li, Eric J. Cockayne, Laura Espinal, Winnie Wong-Ng
Carbon capture with porous solid state materials requires temperature and/or pressure cycles to absorb and then desorb carbon dioxide (CO2). A critical challenge in developing engineered materials for low-energy-cost carbon capture and storage applications is to understand the fundamentals of adsorption, particularly when the material exhibits hysteretic sorption behavior, where the path to adsorption of CO2 molecules differs from that of desorption. We have used first-principles total energy calculations, based on density functional theory and combined with experiments to explore CO2 sorption behavior in a nanoporous solid: cryptomelane-type manganese dioxide OMS-2. Cations present in the large tunnels of this material not only stabilize its porous structure, but also tailor the interaction of CO2 with the pores. We found that the concentration, type and charge of cations have significant effects on CO2 adsorption, diffusion, and predicted hysteresis behavior. In particular, OMS-2 with lower-charge cations such as K+ (Cryptomelane) is predicted to exhibit less hysteresis than OMS-2 with higher-charge cations such as Ba2+ (Hollandite).
, Cockayne, E.
, Espinal, L.
and Wong-Ng, W.
First-principles Studies of Carbon Dioxide Adsorption in Cryptomelane/Hollandite-Type Manganese Dioxide, Chemical Physics Letters
(Accessed December 2, 2023)