Martian Redox Chemistry: Oxygen Reduction in Low-Temperature Magnesium Perchlorate Brines

NASA has a mandate to send humans to Mars by 2033. Recent discoveries regarding Mars include the likely presence of low-temperature liquid brines on the planet’s surface. This work investigates redox chemistry in near saturated aqueous 2.8 M Mg­(ClO₄)₂ at temperatures as low as −34 °C. These conditions are comparable to those thought to be found on the Martian surface. In particular, electro-reduction of oxygen is studied, and the diffusion coefficient and solubility of this important redox species are established.