Enhanced thermal stability and red-ox activity of PrBaMn2-xFexO6–δ oxides

Abstract

The design of new oxygen storage materials remains the key factor for intensive progress in technologies of air-free hydrocarbons combustion. The influence of the iron concentration on the oxygen storage characteristics of solid solutions PrBaMn2–xFexO6–δ is discussed. The complex oxides are synthesized via combined glycine-glycerol-nitrate precursor route. Dependence of unit cell parameters on iron content is estimated by X-ray powder diffraction at heating and an extended solid solution is shown to be formed up to x = 1.00. The temperature increase, as well as iron doping, is shown to be favorable factors for the crystallization of highly symmetric perovskites. Thermogravimetry with differential scanning calorimetry is used to demonstrate a phase stability of iron doped materials at elevated temperatures in air. Solid solutions exhibit large oxygen storage capacity and excellent reversibility of exchange under switching gas phase between air ↔ 5% H2 in Ar. With the increase of iron concentration, the kinetics of redox processes are shown to decline which caused by suppression in anisotropy of thermal expansion under doping.