3D hollow structured Co2FeO4/MWCNT as an efficient non-precious metal electrocatalyst for oxygen reduction reaction

Abstract

A template- and surfactant-free strategy is developed to prepare a hollow structured Co₂FeO₄/MWCNT electrocatalyst, which has been successfully used as a highly efficient non-precious metal electrocatalyst for the oxygen reduction reaction (ORR) in alkaline media. The hollow structured Co₂FeO₄ particles are transformed from solid Co₂Fe nanoparticles via the Kirkendall effect, which increases their active sites and improves the contact between the electrolyte and catalyst surfaces and then enhances the electrocatalytic activity. Furthermore, the hollow structured Co₂FeO₄/MWCNT exhibits excellent long term stability and high methanol tolerance compared to commercial Pt/C. The hollow structured Co₂FeO₄/MWCNT electrocatalysts synthesized herein are promising electrode materials for fuel cell applications and the facile synthesis method could be used in low-cost and large-scale materials production, facilitating the screening of high efficiency catalysts.