Selective Oxidation of Methane to Methanol over Au/H-MOR

Selectiveoxidation of methane to methanol by dioxygen (O-2) is anappealing route for upgrading abundant methane resource andrepresents one of the most challenging reactions in chemistry dueto the overwhelmingly higher reactivity of the product (methanol)versus the reactant (methane). Here, we report that gold nanoparticlesdispersed on mordenite efficiently catalyze the selective oxidationof methane to methanol by molecular oxygen in aqueous medium in thepresence of carbon monoxide. The methanol productivity reaches 1300 mu mol g(cat) (-1) h(-1) or 280 mmol g(Au) (-1) h(-1) with 75% selectivity at 150 degrees C, outperforming most catalystsreported under comparable conditions. Both hydroxyl radicals and hydroperoxidespecies participate in the activation and conversion of methane, whileit is shown that the lower affinity of methanol on gold mainly accountsfor higher methanol selectivity.