REMnO3 (RE = Pr, Nd, Sm, Eu, Gd) perovskite as efficient catalysts for oxygen reduction reaction

Rare earth metal based perovskite emerges as important catalytic material for energy production and storage. These ABO3 type materials are now the focus of research in the field of oxygen reduction and evolution reactions. Here, in this work we evaluated the oxygen reduction properties of thesynthesized one-dimensional REMnO3 (RE = Pr, Nd, Sm, Eu and Gd). The one-dimensional REMnO3 prepared by the hydrothermal synthesis route results in pure phase perovskite on calcinations. The perovskite was characterized with X-ray diffraction, Fourier transform-infrared (FT-IR), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The oxygen reduction reaction activities were investigated with the help of electrochemical workstation that consists of three-electrode system immersed in 0.1 mol/L KOH electrolyte solution saturated with oxygen. The Koutechy–Levich plot obtained from rotating ring disk electrode shows all the prepared catalysts follow 4e– processes during oxygen reduction. The effect of “A” site cation variation in REMnO3 on oxygen reduction reaction is discussed. SmMnO3 shows better onset potential for oxygen reduction reaction among the prepared rare earth perovskite. SmMnO3 having high RE:Mn ratio (A-site rich compositions) promotes oxygen reduction reaction (ORR) activity. All the perovskites show good oxygen reduction property with high stability and methanol tolerance.