Fe binuclear sites convert methane to acetic acid with ultrahigh selectivity

Summary The direct conversion of methane to C2 oxygenates with high selectivity under mild conditions has attracted wide attention but still remains a great challenge. Herein, we report the conversion of methane to acetic acid (CH 3 COOH) with ultrahigh selectivity for oxygenated products by the direct coupling of CH 4 , CO, and H 2 O 2 over ZSM-5-supported Fe binuclear sites under 30°C. The unexpected ultrahigh selectivity toward CH 3 COOH was attributed to the unique Fe binuclear site structure of [Fe(III)–( μ O) 2 –Fe(III)–(OH) 2 ], which was evidenced by advanced spectroscopic techniques and density functional theory (DFT) calculations. It was suggested that the lower energy barriers for the direct coupling of methyl radicals (·CH 3 ) and adsorbed CO∗ and OH∗ species to form CH 3 COOH, compared with the oxidation of CH 4 by OH∗ to form CH 3 OH, benefited the CH 3 COOH formation.