LaNi(1−x)FexO3 perovskite catalysts prepared by high-energy ball milling for efficient air cathodes in alkaline fuel cells

Abstract

The LaNi_(1−x)Fe_xO₃ (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) perovskite powder was prepared using a conventional mixed-oxide method through high-energy ball milling and calcination at 800 °C. The powders were then sintered at 1000 °C for 2 hours with a heating/cooling rate of 5 °C min⁻¹. The LaNi_(1−x)Fe_xO₃ powders were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and cyclic voltammetry (CV). From the experimental results, it was found that the SEM micrograph of the LaNi_0.6Fe_0.4O₃ powder shows that the calcined LaNi_0.6Fe_0.4O₃ powder has a particle size ranging from approximately 30 to 400 nm. In comparison, the sintered powder at 1000 °C has an average particle size ranging from 50 to 600 nm. The LaNi_0.6Fe_0.4O₃ powder exhibits a rhombohedral phase structure. The LaNi_0.6Fe_0.4O₃ catalyst, when used in a 0.1 M local sorbitol solution and 0.1 M KOH, can be effectively utilized as a catalyst for electro-oxidation electrode materials in the oxygen reduction reaction.