Reducibility and catalytic behavior of La0.25Sr1.75MnO4 Ruddlesden- Popper phase prepared by a modified Pechini method

Abstract

Few studies have been reported concerning the use of manganite compounds (La,Sr)2MnO4 of Ruddlesden-Popper structure type as Solid Oxide Fuel Cells (SOFCs) electrode materials; in particular, on the anode side. In the present work La0.25Sr1.75MnO4 compound was synthesized by a modified Pechini method. This prepared manganite was characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and its structure was analyzed into detail by refinement of recorded XRD profiles. La0.25Sr1.75MnO4 was also subjected to a reducibility study through Temperature Programmed Reduction (TPR) and the catalytic properties for total and/or partial oxidation of methane were evaluated. Estimated values of lattice parameters in the refinement are in good agreement with those reported in the literature for various neighbored compositions of the series. The reduction of the material in diluted H2 occurs in several stages and the decomposition starts above 800°C. In the catalytic studies, the material acts as a catalyst for total oxidation of methane even in oxygen deficient atmospheres.

Keywords

• SOFC
• anode
• manganite
• XRD
• TPR
• catalytic oxidation