Oxidative Coupling Of Methanol With Molecularly Adsorbed Oxygen On Au Surface To Methyl Formate

Supported Au catalysts efficiently catalyze the oxidative coupling of methanol with O-2 to methyl formate, in which the atomic O species (O(a)) formed via O-2 dissociation on the Au surface has been considered as the active oxygen species. Herein we report for the first time that the oxidative coupling of methanol can occur facilely with molecularly adsorbed O-2 species (O-2 (a)) on a Au(997) surface at temperatures as low as around 125 K, while that with O(a) occurs at around 175 K. Both experimental and theoretical calculation results demonstrate a novel reaction mechanism of oxidative coupling of CH3OH with O-2 (a) via a dioxymethylene (H2COO) intermediate, resulting in the production of both HCOOCH3 and HCOOCH3 . These results reveal the unique reactivity of molecularly adsorbed O-2 species on Au surfaces for low-temperature oxidation reactions.