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

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