Understanding carbon dioxide capture on metal-organic frameworks from first-principles theory: The case of MIL-53(X), with X = Fe3+, Al3+, and Cu2

Giane B Damas; Luciano T Costa; Rajeev Ahuja; C Moyses Araujo

doi:10.1063/5.0054874

Understanding carbon dioxide capture on metal-organic frameworks from first-principles theory: The case of MIL-53(X), with X = Fe³⁺, Al³⁺, and Cu²

J Chem Phys. 2021 Jul 14;155(2):024701. doi: 10.1063/5.0054874.

Authors

Giane B Damas¹, Luciano T Costa², Rajeev Ahuja¹, C Moyses Araujo¹

Affiliations

¹ Materials Theory Division, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden.
² MolMod-CS- Department of Physical-Chemistry, Campus Valonguinho, Institute of Chemistry, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.

PMID: 34266252
DOI: 10.1063/5.0054874

Abstract

Metal-organic frameworks (MOFs) constitute a class of three-dimensional porous materials that have shown applicability for carbon dioxide capture at low pressures, which is particularly advantageous in dealing with the well-known environmental problem related to the carbon dioxide emissions into the atmosphere. In this work, the effect of changing the metallic center in the inorganic counterpart of MIL-53 (X), where X = Fe³⁺, Al³⁺, and Cu²⁺, has been assessed over the ability of the porous material to adsorb carbon dioxide by means of first-principles theory. In general, the non-spin polarized computational method has led to adsorption energies in fair agreement with the experimental outcomes, where the carbon dioxide stabilizes at the pore center through long-range interactions via oxygen atoms with the axial hydroxyl groups in the inorganic counterpart. However, spin-polarization effects in connection with the Hubbard corrections, on Fe 3d and Cu 3d states, were needed to properly describe the metal orbital occupancy in the open-shell systems (Fe- and Cu-based MOFs). This methodology gave rise to a coherent high-spin configuration, with five unpaired electrons, for Fe atoms leading to a better agreement with the experimental results. Within the GGA+U level of theory, the binding energy for the Cu-based MOF is found to be E_b = -35.85 kJ/mol, which is within the desirable values for gas capture applications. Moreover, it has been verified that the adsorption energetics is dominated by the gas-framework and internal weak interactions.