Tuning Lewis acid in nickel-containing polyoxometalates for enhanced ethanol selectivity of methane electrooxidation reactions

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,…