11　Shortening the time and saving the energy of Fe/N/Ketjenblack catalyst preparation and improving the oxygen reduction ability by a microwave method

Abstract

Fe/N/C oxygen reduction catalysts have problems with low oxygen reduction reaction (ORR) activity and durability, as well as a considerable consumption of time and energy during synthesis. The objective of this study is to improve the activity and the energy efficiency of Fe/N/C catalysts in the synthesis process through the application of microwave synthesis. The precursors were prepared using microwave irradiation as an alternative to heat under reflux, followed by subsequent heat-treatments. The ORR current and 4e⁻ efficiency for the catalysts prepared by a microwave method were 1.2 and 1.1 times higher than those prepared by the reflux method, respectively. It is suggested that the microwave method increased active sites and improved activity of catalyst. The time required for synthesis of the Fe/N/C catalysts was reduced to one-third by the microwave method.