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

Abstract:

The pure MnO and Mn₂O₃ doped MnO catalysts for oxygen reduction were synthesized by reducing maganese oxide under ammonia and hydrogen atmosphere seperately. X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy tests ascertained the synthesis of the two kinds of catalysts. The cyclic voltammetry, tafel, linear scanning voltammetry and current-time chronoamperometric tests proved that the potential of peak current of oxygen redcution located in the rage of -0.5 to -0.1V. The doping of Mn₂O₃ enhanced the peak potential of oxygen reduction. Both the rotate disc electrode and rotate ring disc electrode tests confirmed that the ORR were major happened through 4-electron reaction style under the catalysis of Mn₂O₃ doped MnO, thus, through 2-electron style onder the catalysis of pure MnO. It is approved that the doping of Mn₂O₃ improved the catalysis of MnO. The coexistence of ions with different valents can promote the promote the catalytic activity.