Oxygen Reduction Activity on a Nanosized Perovskite Type Oxide Prepared by Polyvinyl Pyrrolidone Method

Abstract

A nanosized perovskitetype oxide supported on carbon black (perovskite/C) was prepared by the polyvinyl pyrrolidone (PVP) addition method and subsequent mechanical milling with carbon black. Transmission electron microscope (TEM) observation and scanning transmission electron microscope (STEM)–energy dispersive Xray (EDX) mapping clearly revealed that the oxide prepared by the PVP method was small (ca. 20 nm) and highly dispersed on the carbon support. The oxygen reduction reaction (ORR) activity on the perovskite/C catalyst was investigated with rotating ringdisk electrode (RRDE) measurement in an alkaline solution at 25 آ°C. The prepared perovskite/C catalyst showed enhanced activity compared to catalysts obtained by the conventional solid state reaction and citrate process; i.e., a positive shift of the onset potential and increased ORR current at a disk electrode. The present catalyst was also associated with decreased ring current.