Splitting dioxygen over distant binuclear transition metal cationic sites in zeolites. Effect of the transition metal cation.

Splitting dioxygen to yield highly active oxygen species attracts enormous attention due to its potential in direct oxidation reactions, mainly in transformation of methane into valuable products. Distant binuclear cationic Fe(II) centers in Fe‐ferrierite have recently been shown to be active in splitting dioxygen at room temperature to form very active oxygen species able to oxidize methane to methanol at room temperature as well. Computational models of the distant binuclear transition metal cationic sites (Co(II), Mn(II), and Fe(II)) stabilized in the ferrierite matrix were investigated by periodic density‐functional theory calculations including molecular dynamics simulations. The results reveal that the M(II) cations capable of the M(II) → M(IV) redox cycle with the M...M distance of ca 7.4 Å stabilized in two adjacent β sites of ferrierite can split dioxygen. Our study opens the possibility of developing tunable zeolite‐based systems for the activation of dioxygen employed for direct oxidations. [ABSTRACT FROM AUTHOR]