A PEROVSKITE-BASED OXIDE FOR OXYGEN STORAGE AND A METHOD FOR PREPARATION THEREOF

摘要

A method for preparation of a perovskite-based oxide of the chemical formula: BaLnMn 2 O 5+´ , where Ln represents at least one element selected from the group consisting of: Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu or a mixture of elements from the group consisting of: Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y, the method comprising synthesizing a perovskite precursor by a sol-gel method comprising the steps of: dissolving nitrates of respective elements in water, evaporating water to obtain a perovskite precursor, decompose excessive nitrates and oxidize carbon residues, grinding the perovskite precursor to a powdered perovskite precursor, annealing the powdered perovskite precursor in an atmosphere of 1vol.% of H 2 in Ar, at a temperature range from 1000 to 1100°C and cooling the obtained perovskite of the formula BaLaMn 2 O 5+´ . The method further comprises the following steps: high energy milling of the obtained perovskite of the formula BaLaMn 2 O 5+´ for 5 to 30 minutes, and activating of the material by consecutive isothermal oxidation/reduction at the temperature of 500°C in a reducing atmosphere of H 2 in Ar and in an oxidizing atmosphere of air.