Well-dispersed Co3Fe7 alloy nanoparticles wrapped in N-doped defect-rich carbon nanosheets as a highly efficient and methanol-resistant catalyst for oxygen-reduction reaction

Abstract To explore alkaline fuel cells in practice, searching low-cost and efficient alternatives to Pt-based catalysts is urgent yet challenging for oxygen reduction reaction (ORR). Herein, Co3Fe7 alloy nanoparticles wrapped in N-doped defect-rich carbon nanosheets (Co3Fe7/CNs) were synthesized at 800 °C by a one-step pyrolysis of the mixture (dicyandiamide, iron (II) phthalocyanine (FePc), cobalt (II) phthalocyanine (CoPc) and Fe2O3), defined as Co3Fe7/CNs-800 for simplicity. The pyrolysis temperature and the dosages of dicyandiamide closely correlated to the ORR performance of the resultant catalysts in 0.1 M KOH solution. Significantly, the optimized Co3Fe7/CNs-800 exhibited encouraging onset potential (Eonset = 0.97 V) and half-wave potential (E1/2 = 0.85 V) in the alkaline media, surpassing commercial Pt/C (50 wt%, Eonset = 0.96 V, E1/2 = 0.84 V). This work provides a feasible strategy for developing efficient non-noble metal ORR electrocatalysts in the alkaline condition.