Formation of atomic fluorine anions in 12CaO·7Al2O3

摘要

The storage of atomic fluorine anions (F ? ) is an important issue in the development of emission materials that have numerous technological applications including catalysis. Using density functional theory simulations, we examine the formation of F ? ions from gaseous F 2 in the nanoporous complex oxide 12CaO·7Al 2 O 3 (C12A7). Both stoichiometric and electride forms of C12A7 strongly encapsulate fluorine atoms, and the formation of F ? ions is confirmed from the charge analysis. There is a significant enhancement in the encapsulation in the electride form of C12A7 due to the presence of electrons in its nanocages. Successive encapsulation of multiple F atoms is also energetically favorable in both forms of C12A7. The formation of molecular fluorine (F 2 ) in the nanocages of both forms is unfavorable due to the strong electronegativity of fluorine.