Highly efficient electrocatalysts with CoO/CoFe2O4 composites embedded within N-doped porous carbon materials prepared by hard-template method for oxygen reduction reaction

Abstract

Low-cost dual transition metal (Fe and Co) based non-noble metal electrocatalysts (NNMEs) have been explored to enhance the oxygen reduction reaction (ORR) performance in both alkaline and acidic solution. In this work, novel NNMEs derived from iron, cobalt and N-doped porous carbon materials (FeCo/NPC) were fabricated with magnesium oxide (MgO) as the hard-template. By optimizing the pyrolysis temperature (600 to 1000 °C) and the molar ratio of Fe to Co (Co, FeCo₃, FeCo, Fe₃Co, Fe), the highly active electrocatalyst FeCo/NPC (900) for ORR in alkaline solution was prepared, which possessed a large surface area of 958 m² g⁻¹. The onset potential (E_onset) and half-wave potential (E_1/2) of FeCo/NPC (900) were 0.934 V and 0.865 V, respectively, comparable to the best values of NNMEs reported so far in ORR tests under alkaline conditions. Additionally, FeCo/NPC (900) exhibited better electrocatalytic properties than commercial Pt/C in terms of durability and the tolerance to methanol in alkaline media.