Mn2O3 oxide with bixbyite structure for the electrochemical oxygen reduction reaction in alkaline media: Highly active if properly manipulated

We consider compositional and structural factors which can affect the activity of bixbyite ?-Mn2O3 towards oxygen reduction reaction (ORR) stability this oxide in alkaline solution. compare electrochemistry undoped, Fe Al-doped with structure braunite Mn7SiO12 having bixbyite-related crystal structure, using rotating disk electrode (RDE), ring-disk (RRDE), cyclic voltammetry (CV) techniques. All manganese oxides under study are stable potential range between ORR onset ca. 0.7 V vs. Reversible Hydrogen Electrode (RHE). It is found that any changes introduced and/or composition lead to an drop both hydrogen peroxide reactions interval. For these modifications also result a change nature rate-determining step. The obtained results confirm due its unique crystalline undoped most active (among currently available) Mn catalyst favor assumption key role (111) surface very high material ORR.