Dioxygen dissociation over man-made system at room temperature to form the active α-oxygen for methane oxidation.

ABSTRACT

Activation of dioxygen attracts enormous attention due to its potential for utilization of methane and applications in other selective oxidation reactions. We report a cleavage of dioxygen at room temperature over distant binuclear Fe(II) species stabilized in an aluminosilicate matrix. A pair of formed distant α-oxygen species [i.e., (Fe(IV)═O)2+] exhibits unique oxidation properties reflected in an outstanding activity in the oxidation of methane to methanol at room temperature. Designing a man-made system that mimicks the enzyme functionality in the dioxygen activation using both a different mechanism and structure of the active site represents a breakthrough in catalysis. Our system has an enormous practical importance as a potential industrial catalyst for methane utilization because (i) the Fe(II)/Fe(IV) cycle is reversible, (ii) the active Fe centers are stable under the reaction conditions, and (iii) methanol can be released to gas phase without the necessity of water or water-organic medium extraction.