Investigation of the Redox Behaviour of Double Perovskite PrBaMn2O5+δ

Abstract

A multi-analytical approach (in situ X-ray diffractometry, XRD, temperature programmed reduction TPR, thermogravimetry TGA) was used to deeply study the phase transition between the Pr0.5Ba0.5MnO3- δ (m-PBM) and the double layered perovskite PrBaMn2O5+ δ (l-PBM). m-PBM sample was prepared by an auto-combustion based citrate procedure and exposed to consecutive reduction and oxidation cycles at high temperature to understand the effect of oxidizing and reducing atmospheres on structural changes and stabilization of the layered double perovskite. XRD analysis showed the existence of a pseudo cubic structure (c-PBM), which is formed from the direct oxidation of l-PBM. TPR results confirmed the c-PBM to l-PBM reversibility to the redox processes, and the TGA characterization showed a fast transition between l-PBM to c-PBM. The oxidation of l-PBM to c-PBM seems pivotal for the stabilization of the layered reduced structure. The results are discussed in the perspective to develop versatile electrodes for SOEC/SOFC applications.