Enhancing oxygen reduction catalysis: Microwave-assisted sol–gel synthesis of highly active LaNi0.5Co0.5O3 electrocatalyst

Although metal–air batteries emerge as a highly promising class of fuel cells, improved efficiency is required for the oxygen reduction reaction (ORR) at the air–electrode cathode. Perovskite-type oxides, such as Co-doped LaNiO 3 , can serve as low-cost alternatives to conventional precious-metal-based oxygen electrocatalysts. However, achieving high specific surface areas and oxygen reduction activities necessitates the optimization of the synthesis process. In this study, LaNi 0.5 Co 0.5 O 3 (MV-LNCO), a high-performance perovskite ORR catalyst, is synthesized via an innovative sol–gel method combined with microwave heating. This approach involves the use of polyvinylpyrrolidone as a complexing agent and activated carbon as a pore-forming agent. Notably, the specific surface area of MV-LNCO (50.78 m 2 g −1 ) is nearly twice as large as that of the corresponding catalyst synthesized using the traditional method. Moreover, electrochemical tests revealed that MV-LNCO achieves an improved onset potential (0.87 V), half-wave potential (0.68 V), and limiting current density (5.57 mA cm −2 ) for ORR. In addition to its excellent catalytic activity in ORR, MV-LNCO demonstrates no notable decrease in current output over 8 h, indicating excellent stability. Thus, the developed synthesis method has the potential to provide novel high-performance catalysts for metal–air batteries.