Tailored pore-confined single-site iron(III) catalyst for selective CH oxidation to CHOH or CHCOH using O.

Direct oxidation of methane to valuable oxygenates like alcohols and acetic acid under mild conditions poses a significant challenge due to high C‒H bond dissociation energy, facile overoxidation to CO and CO and the intricacy of C-H activation/C-C coupling. In this work, we develop a multifunctional iron(III) dihydroxyl catalytic species immobilized within a metal-organic framework (MOF) for selective methane oxidation into methanol or acetic acid at different reaction conditions using O. The active-site isolation of monomeric Fe(OH) species at the MOF nodes, their confinement within the porous framework, and their electron-deficient nature facilitate chemoselective C‒H oxidation, yielding methanol or acetic acid with high productivities of and , respectively. Experiments and theoretical calculations suggest that methanol formation occurs via a Fe-Fe-Fe catalytic cycle, whereas CHCOH is produced via hydrocarboxylation of in-situ generated CHOH with CO and H, and direct CH carboxylation with CO.