Electrocatalytic Methane Oxidation to Ethanol via Rh/ZnO Nanosheets

The direct conversion of methane to value-added chemicals at ambient conditions is a long-awaited perspective, and the electrocatalytic methane oxidation reaction (CH4OR) offers the potential of utilizing abundant natural gas and renewable energy sources. However, due to the competition of water oxidation and the overoxidation of methane, CH4OR has remained as a significant challenge. In this work, we developed Rh/ZnO nanosheets as an effective catalyst for electrochemical conversion of methane into ethanol. The highly dispersed rhodium nanoparticles provided surface sites for methane adsorption, and ZnO allowed presentation of abundant active oxygen species for methane activation. With a 0.6% Rh doping ratio, the Rh/ZnO nanosheets demonstrated an excellent ethanol production rate of 789 μmol·gcat –1·h–1 at 2.2 V versus reversible hydrogen electrode, corresponding to a Faradaic efficiency of 22.5% and an ethanol production selectivity of 85%, suggesting a promising means for methane utilization at ambient conditions.