Carbon-supported La1-xCaxMn1-yFe yO3 nanoparticles were synthesized, and their oxygen reduction activities and electronic states were investigated. A reverse micelle method using KMnO4 as a source of high valence state Mn successfully yielded carbon-supported La1-xCaxMn1-yFe yO3 nanoparticles even when calcined under a reducing atmosphere. The oxygen reduction activity of carbon-supported La 1-xCaxMn1-yFeyO3 exceeded that of carbon-supported Pt nanoparticles when the Ca composition was limited to the range of 0.4 to 0.8. X-ray photoelectron spectroscopy (XPS) measurements of La1-xCaxMn1-yFeyO3 particle surfaces revealed the existence of Mn4+, which is important in the oxygen reduction activity. Depth analysis of La1-xCa xMn1-yFeyO3 nanoparticles by XPS revealed the formation of a CaCO3 impurity and an A-site deficient perovskite-type oxide containing a high surface concentration of Mn 4+.
!!!All Science Journal Classification (ASJC) codes
- 化学 (全般)