Selective Electrochemical Oxidation of Methane to Ethanol over the Co3O4/La2O2CO3 Heterojunction Catalyst

Catalyzing methane (CH4) at room temperature to value-added products is a promising approach, but high product selectivity remains a challenge. In this study, La2CoO3 was used as a precursor to synthesize xLC (xCo(3)O(4)/La2CoO3) by adjusting the molar ratio of Co and La. When glycerol was added for hydrothermal modification, a carbon source was introduced into xLC to form an efficient heterojunction material xLC-C (xCo(3)O(4)/La2O2CO3) capable of converting CH4 to ethanol at 2.2 V (vs RHE). Moreover, 3.5LC-C was found to convert CH4 with a current density difference of up to 17.86 mA/cm(2) and ethanol yields of 627 mu mol/g(cat)/h. Density functional theory calculations indicate that the high reactivity results from an increased internal charge distribution following the introduction of La2O2CO3 into the Co3O4 system, which provides electron transport and reactive oxygen species to activate the C-H bond. Co3O4 serves as the active phase, providing a site for the adsorption and conversion of CH4. The presence of La2O2CO3 in this study reduces the reaction residence time, thus inhibiting C-C coupling reactions between intermediates such as CH4 and HCHO, impeding the formation of long-chain alcohols and achieving high product selectivity.