Using density functional theory to study shape-reactivity relationships in Keggin Al-nanoclusters

作者：Corum Katie W; Mason Sara E

来源：Water Research, 2016, 102: 413-420.

DOI：10.1016/j.watres.2016.06.043

• Al Keggins
• Al polycations
• DFT
• Al-30
• Reactivity
• Adsorption

Keggin-based aluminum nanoclusters have been shown to be efficient sorbents for the removal of arsenic from water. Obtaining a molecular-level understanding of the adsorption processes associated with these molecules is of fundamental importance, and could pave the way for rational design strategies for water treatment. Due to their size and the availability of experimental crystal structures, Al nano clusters are computationally tractable at the density functional theory (DFT) level. Here, we compare the reactivity of three aluminum polycations: [Al13O4(OH)(24)(H2O)(12)](7+) (Al-13), [Al30O8(OH)(56)(H2O)(26)](18+), (Al-30), and [Al32O8(OH)(60)(H2O)(30)](20+) (Al-32). We use DFT calculations to determine reactivity as a function of particle topography, using sulfate and chloride as adsorption probes. Our comparative modeling of outer-sphere adsorption of Cl- and SO42- on Al-13, Al-30, and Al-32 supports that the unique "hourglass" shape characteristic to Al-30 gives rise to relatively strong adsorption in the molecular beltway, as well as a wide range of reaction energies as a function of particle topography.

• 出版日期2016-10-1