Mn2O3 doping induced the improvement of catalytic performance for oxygen reduction of MnO

In this study, the catalyst of reduced graphene oxide (rGO) supported Mn2O3 doped MnO for oxygen reduction reaction (ORR) has been successfully synthesized. The structures and morphology of the Mn2O3 doped MnO were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). XRD tests reveal that the Mn2O3 is successfully doped to MnO. The cyclic voltammetry, Tafel, linear scanning voltammetry and current-time chronoamperometric tests prove that the Mn2O3 doped MnO has a better catalytic performance and stronger stability than pure MnO for oxygen reduction. Both the rotating disc electrode and rotating ring disc electrode tests approve that the ORR happens mainly through 4-electron reaction mechanism on Mn2O3 doped MnO. The ORR happens mainly through 2-electron reaction mechanism with the catalysis of pure MnO. The coexistence of manganese ions with different valent promotes the catalytic performance of metal oxide for oxygen reduction.