Low-Temperature Conversion of Methane to Methanol on CeO_<i>x</i>/Cu₂O Catalysts: Water Controlled Activation of the C–H Bond

Abstract

An inverse CeO₂/Cu₂O/Cu(111) catalyst is able to activate methane at room temperature producing C, CH_x fragments and CO_x species on the oxide surface. The addition of water to the system leads to a drastic change in the selectivity of methane activation yielding only adsorbed CH_x fragments. At a temperature of 450 K, in the presence of water, a CH₄ → CH₃OH catalytic transformation occurs with a high selectivity. OH groups formed by the dissociation of water saturate the catalyst surface, removing sites that could decompose CH_x fragments, and generating centers on which methane can directly interact to yield methanol.