Mesoporous manganese oxides using hydrothermal method with non-ionic surfactant for oxygen reduction reaction

초록

Currently, tremendous researches have been investigated in electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for fuel cells and water splitting. Platinum is considered as the electrocatalyst for the highest activity in ORR. However, use of Pt as electrode for ORR is limited due to high price and low abundance. Therefore, non-precious metal catalysts for ORR have attracted enormous interest as an alternative to platinum. Especially, manganese oxides showed enhanced electrocatalytic activity for ORR owing to redox properties. In this study, mesoporous manganese oxide was successfully fabricated via hydrothermal method with non-ionic surfactant such as F127. Crystallinities of the synthesized manganese oxides were investigated by X-ray diffraction (XRD), and the surface composition was measured by X-ray photoelectron spectroscopy (XPS). The porous structure and surface morphology of the samples were also obtained by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Brunauer-Emmer-Teller (BET) was used to determine surface area of porous manganese oxide. Rotating disk electrode (RDE) was utilized to investigate the electrocatayltic activity for ORR.