Enhanced electrocatalytic activity of a hierarchical CeO2 @MnO2 core-shell composite for oxygen reduction reaction.

Abstract A novel MnO 2 nanosheet-coated CeO 2 nanosphere (CeO 2 @MnO 2) core-shell composite was successfully prepared by a simple two-step hydrothermal process as efficient catalyst for oxygen reduction reaction (ORR). XRD, XPS, SEM and TEM analysis techniques were sequentially employed to evidence this CeO 2 core-MnO 2 shell structure. When utilized for ORR catalyst, such hierarchical core-shell structured CeO 2 @MnO 2 composite delivers a superior electrocatalytic activity than that of MnO 2 nanoflowers and CeO 2 nanospheres, which is in close proximity to that of commercial 20 wt% Pt/C in alkaline solution, and also exhibits an excellent durability. These properties make the composite potential as cathode catalyst for metal-air battery application. In addition, the enhanced mechanism arising from the synergetic effect of the MnO 2 and CeO 2 was preliminarily discussed. [ABSTRACT FROM AUTHOR]