Estudo dos parâmetros de síntese na obtenção da fase La2Ce2O7 para aplicação em células a combustível

Abstract

Ceramic materials composed of rare earth elements have properties that arouse interest for applications in different areas. In hydrogen production, these materials can be used as electrolytes in fuel cells, but as thermal barriers, they can be used in the coating of components exposed to high temperatures. Given these possibilities, this study aims to obtain La2Ce2O7 via hydrothermal synthesis with variation in the synthesis parameters in order to evaluate its influence on the production of the desired material. The materials produced were evaluated through: X-Ray Diffraction, X-Ray Fluorescence, Scanning Electron Microscopy, X-Ray Dispersive Energy Spectroscopy and Raman Spectroscopy. These characterization techniques allowed the identification of the crystalline phases, concentration of the elements present in the samples, chemical mapping, morphology and presence of oxygen vacancies in the catalysts. The results point to the formation of lanthanum and cerium oxides and absence of the desired phase. Sodium was found as a residual element of the synthesis process on the surface of the material. The lanthanum, Cerium and sodium elements are homogeneously distributed in all the samples and the presence of oxygen vacancies in three of the four materials produced, reveal their catalytic potential in the evaluated synthesis conditions.