The year of 2020 is definitely memorable. We are forced to adapt to the covid-19 pandemic as an on-going challenge. Oxygen gas becomes a “strategic” commodity during the covid-19 pandemic which is essential to the medical therapy. The indispensability of oxygen also lies in future colony on Mars. Considering the fact that the main contents of atmosphere and soil of Mars are CO2 and oxide ores, the isolation of oxygen from the oxides ores and atmospheric CO2 is a cherished wish and an imperative task as a stargazer on Mars. We recently integrate the electrochemical reduction of CO2 and Fe2O3 in molten salts to produce advanced Fe3C-based electrocatalyst and oxygen with a current efficiency higher than 90%. The obtained Fe3C-based electrocatalyst outperforms the-state-of-art RuO2 towards the oxygen evolution reaction. The above results are now accepted for publication in Angew. Chem. Int. Ed. as a VIP.