Ab initio free energy calculations for gas adsorption and separation in nanoporous systems
ChE-605 - Highlights in Energy Research seminar series
EPFL Valais Wallis
Metal-organic frameworks (MOFs) are promising materials for gas storage, e.g. storage of energy carriers such as H2, and gas separation processes, e.g. removal of CO2 from CH4. The rational design of new adsorbents with enhanced separation performance at optimized separation conditions requires reliable predictions of adsorption isotherms and co-adsorption selectivities with no other input than the atomic position. This we achieve with Grand Canonical Monte Carlo (GCMC) simulations on a lattice of adsorption sites. The Hamiltonian is defined by Gibbs free energies of adsorption on individual sites and lateral interaction energies (adsorbate-adsorbate) calculated, both obtained with quantum chemical ab initiocalculations.
Currently, co-adsorption isotherms are almost exclusively obtained from single component isotherms using the Ideal Adsorbed Solution Theory (IAST). Based on our ab initio calculation we analyse the underlying approximations and propose an improved model for systems with strong lateral interactions.
- Institute of Chemistry, Humboldt University, Berlin, Germany
Art der Veranstaltung: Vortrag/Konferenz