Synthesis of YFeO_3-δ and LaFeO_3-δ Perovskites with High Catalytic Activity in Carbon Oxidation Reactions

Abstract

YFeO3-δ (δ = 0.26) and LaFeO3-δ (δ = 0.5) perovskites with a high specific surface and oxygen non-stoichiometry was firstly synthesized by pyrolysis of polymer-salt compositions. It was shown that the catalytic oxidation of carbon in the presence of these complex oxide systems proceeds in the range of 400 - 700 °С, with a maximum temperature at 556 °С for YFeO3-δ; and 380 - 620 °С ,with a maximum temperature at 501 °С for LaFeO3-δ, in one-stage mode for both. By means of thermal analysis and diffractometry, it was shown that there is no contribution to the soot oxidation mechanism by cyclic perovskite surface transformations, due to the reduction of metal oxides by the soot and their subsequent reoxidation. It has been established that the basis of the catalytic reaction mechanism for both perovskites is the presence of oxygen vacancies on the surface of complex oxides.