Highly efficient Fe–Cu dual-site nanoparticles supported on black pearls 2000 (carbon black) as oxygen reduction reaction catalysts for Al–air batteries

Abstract

Acquiring cost-effective, high-performance, non-precious metal catalysts is crucial for substituting precious metal catalysts in the oxygen reduction reaction (ORR) to ensure sustainable energy conversion. Herein, we present a preparation strategy for a high-performance Cu–Fe–CN-3 electrocatalyst characterized via X-ray diffraction (XRD), Raman spectroscopy, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. The results demonstrated that the incorporation of Cu and Fe into Black Pearls' carbon black (BP2000) and the strong synergistic effect between Fe and Cu contributed to the enhancement of active sites for the ORR. Electrochemical characterization revealed that the Cu–Fe–CN-3 catalyst synthesized by mixing Cu and Fe in a molar ratio of 3 : 1 exhibits superior catalytic activity for the ORR. The ORR performance of the Cu–Fe–CN-3 catalyst in an alkaline electrolyte (E_1/2 0.867 V vs. RHE) surpassed that of Pt/C (E_1/2 0.841 V vs. RHE), and the assembled aluminum–air battery demonstrated superior voltage stability compared to Pt/C under the same current density. After 2000 cycles, the E_1/2 of the Cu–Fe–CN-3 catalyst exhibited a slight negative shift by 5 mV, which was better than the activity loss of the Pt/C catalyst (12 mV). At the same current density, the average discharge platform of Al–air batteries with the Cu–Fe–CN-3 catalyst was better than that of the commercial Pt/C catalyst. Therefore, the prepared Cu–Fe–CN-3 electrocatalyst exhibits great potential as an efficient ORR catalyst in fuel cells.