Enhanced electrocatalytic performance of perovskite supported iron oxide nanoparticles for oxygen reduction reaction

Abstract

Perovskite oxide based materials have drawn considerable amount of attention as non-precious, non-noble cathode catalysts in oxygen reduction reactions for fuel cell and battery applications. High efficiency of perovskite catalysts often suffers due to instability and poor conductivity issues. Thus, the integration of these perovskite materials with other active catalysts is be of great interest. In this article, a series of new nanocomposites of perovskite–iron oxide with different molar ratios has been developed by hydrothermal method. We have shown that double perovskite calcium copper titanate CaCu₃Ti₄O₁₂ (CCTO) supported iron oxide (Fe₂O₃) catalysts exhibit excellent activity as cathode catalyst for oxygen reduction reactions in fuel cells. Three different composites of CaCu₃Ti₄O₁₂ (CCTO) with Fe₂O₃ were prepared and the composites were analysed by various structural and microstructural characterization methods, such as XRD and FESEM. Microstructural investigations revealed cubic shaped iron oxide nanoparticles decorated over CCTO particles. Electrochemical analysis showed that the performance of composites improved drastically with increase in the amount of CCTO. Kinetic studies by rotating ring disc electrode method revealed that the composites exhibit four electron pathway for oxygen reduction reaction and generate hydrogen peroxide as an intermediate. This work demonstrates a new type of efficient metal oxide–perovskite composite for oxygen redution catalysis.