A coordinatively unsaturated single iron site confined in a graphene matrix shows an ultrahigh activity for catalytic oxidation.

Graphene-confined single Fe atoms, screened out from a series of 3d transition metals (Mn, Fe, Co, Ni, and Cu), were used as an efficient non-precious catalyst to directly convert methane to C1 oxygenated products at room temperature. The unique O-FeN 4 -O structure formed in graphene can readily activate the C-H bond of methane along a radical pathway with a low reaction energy barrier.