We have performed first-principles density functional theory calculations, incorporated with van der Waals interactions, to study CO2 adsorption and diffusion in nanoporous solid – OMS-2 (Octahedral Molecular Sieve). We found the charge, type, and mobility of a cation, accommodated in a porous OMS-2 material for structural stability, can affect not only the OMS-2 structural features but also CO2 sorption performance. This paper targets K+, Na+, and Ba2+ cations. First-principles energetics and electronic structure calculations indicate that Ba2+ has the strongest interaction with the OMS-2 porous surface due to valence electrons donation to the OMS-2 and molecular orbital hybridization. However, the Ba-doped OMS-2 has the worst CO2 uptake capacity. We also found evidence of sorption hysteresis in the K- and Na-doped OMS-2 materials.
This is an author-created, un-copyedited version of an article published in Journal of Physics D: Applied Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi: 10.1088/0022-3727/48/33/335304
Williamson, Izaak; Nelson, Eric B.; and Li, Lan. (2015). "Carbon Dioxide Sorption in a Nanoporous Octahedral Molecular Sieve". Journal of Physics D: Applied Physics, 48(33), 335304-1 - 335304-7. http://dx.doi.org/10.1088/0022-3727/48/33/335304