Non-precious Co_3O_4 nano-rod electrocatalyst for oxygen reduction reaction in anion-exchange membrane fuel cells

摘要

We report preparation of carbon-supported Co_3O_4 electrocatalysts with nano-rods and spherical structures by the solvent-mediated morphological control method. The catalytic properties of the prepared catalysts for the oxygen reduction reaction (ORR) in alkaline media are investigated. We show that the ORR catalytic activity of the prepared catalysts is sensitive to the number and activity of surface-exposed Co~(3+) ions that can be tailored by the morphology of cobalt oxides. In particular, we demonstrate that the non-precious Co_3O_4 electrocatalyst with the nano-rod structure (~ 12 nm in length and ~5.1 nm in diameter) prepared in the mixed solvent of water to dimethylformamide ratio of 1 : 1 exhibits a higher current density than a much more expensive palladium-based catalyst does at the low potential region.