High-efficiency electrochemical methane conversion using Fe₂O₃-based catalysts assisted by thermochemical active oxygen

Direct methane-alcohol conversion is urgently needed not only for efficient use of methane but also for a sustainable environment. Here, we present hybrid electrochemical methane oxidation with thermochemical generation of active oxygen by employing an Fe₂O₃-based catalyst with a CO₃^2- oxygen source. A mechanistic study, including an electrochemical analysis, elucidates the reaction pathway in which the CO₃^2- activates methane by supplying O* through thermal dissociation over the Fe₂O₃ catalyst, while an electrochemical potential applied to the Fe₂O₃ catalyst promotes the subsequent methane–ethanol conversion. We demonstrate that doping the catalyst with oxophilic Zr into the catalyst enhances ethanol conversion by stabilizing the hydroxyl-containing intermediates. In room-temperature electrochemical methane conversion, we achieve an ethanol production rate of 1677 μmol/g_cat/hr (the total production rate for oxygenates is 1831 μmol/g_cat/hr) with a selectivity of 91 % and an 87 % Faraday efficiency conversion.