Fe³⁺ in a tetrahedral position determined the electrocatalytic properties in FeMn₂O₄

Abstract

Inspired by the flexibility of cation exchange and valence state variation in spinel ferrite, a high activity OER catalyst FeMn2O4 has been observed without inducing the change of composition, morphology, and atomic doping.

Enhanced Electrochemical Performance of MnCo1.5Fe0.5O4Spinel for Oxygen Evolution Reaction through Heat Treatment

“…Qi et al prepared FeMn 2 O 4 spinel nanoparticles using coprecipitation and postannealing at varying temperatures, allowing modulation of the cationic oxidation states and optimization of the OER performance. 19 Increasing the postannealing temperature led to the changes in the spinel internal structure, with higher Fe 2+ /Fe 3+ and slightly increased Mn 3+ /Mn 2+ ratios, which were favorable for the OER performance. Under alkaline conditions, the material produced at 500 °C exhibited the best OER activity.…”

“…The XPS results revealed a higher cobalt content on the surface of nonheated samples compared to those treated to 900 °C, which was attributed to the enhanced catalytic activity in the unannealed samples. Qi et al prepared FeMn 2 O 4 spinel nanoparticles using coprecipitation and postannealing at varying temperatures, allowing modulation of the cationic oxidation states and optimization of the OER performance . Increasing the postannealing temperature led to the changes in the spinel internal structure, with higher Fe 2+ /Fe 3+ and slightly increased Mn 3+ /Mn 2+ ratios, which were favorable for the OER performance.…”