The electrocatalytic oxidation of methane (CH₄) facilitates the direct conversion of abundant natural gas into value-added chemicals utilizing renewable electricity. However, the high dissociation energy of the C-H bond and the presence of multiple competing reaction pathways lead to poor product selectivity. We synthesized a Ni-based polyoxometalate (Ni-POM-VO) through cluster-nucleus co-assembly and introduced rich oxygen vacancies using N₂ cold plasma etching. The optimized catalyst attained a Faradaic efficiency of 88.4% for ethanol at 1.7 V versus the reversible hydrogen electrode (RHE). Notably, the oxygen vacancies in Ni-POM-VO create Lewis acid sites that enhance methane adsorption and activation, thereby facilitating its conversion into *CH2 and *CH₂OH intermediates. The subsequent adsorption of these intermediates onto the polyoxometalate (POM) framework promotes C-C coupling, resulting in ethanol production. This work provides a new method for adjusting the Lewis acid content on the catalyst surface through oxygen vacancies, improving the selectivity of methane electro oxidation to ethanol.
Liu et al. (2026) studied this question.