Selective Electrochemical Oxidation of Methane to Ethanol over the CoO/LaOCO Heterojunction Catalyst.

Catalyzing methane (CH) at room temperature to value-added products is a promising approach, but high product selectivity remains a challenge. In this study, LaCoO was used as a precursor to synthesize LC (CoO/LaCoO) by adjusting the molar ratio of Co and La. When glycerol was added for hydrothermal modification, a carbon source was introduced into LC to form an efficient heterojunction material LC-C (CoO/LaOCO) capable of converting CH to ethanol at 2.2 V (vs RHE). Moreover, 3.5LC-C was found to convert CH with a current density difference of up to 17.86 mA/cm and ethanol yields of 627 μmol/g/h. Density functional theory calculations indicate that the high reactivity results from an increased internal charge distribution following the introduction of LaOCO into the CoO system, which provides electron transport and reactive oxygen species to activate the C-H bond. CoO serves as the active phase, providing a site for the adsorption and conversion of CH. The presence of LaOCO in this study reduces the reaction residence time, thus inhibiting C-C coupling reactions between intermediates such as CH and HCHO, impeding the formation of long-chain alcohols and achieving high product selectivity.