LaFe1−xNixO3 perovskites in the catalytic reaction of high-temperature decomposition of nitrous oxide

Abstract

The catalytic performance of LaFe_1−xNi_xO₃ perovskites prepared by the Pechini method was studied in the high-temperature decomposition reaction of nitrous oxide at temperatures of 750–900 °C. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), adsorption (S_bet) and hydrogen thermo-programmed reduction (H₂-TPR) methods. The prepared single-phase solids with specific surface areas of 4.7–8.4 m² g⁻¹ are porous particles (aggregates) of 10–100 μm composed of microblock crystallites. The surface of all samples is enriched with lanthanum. Increasing the Ni content increases the normalized per m² catalytic activity of LaFe_1−xNi_xO₃ perovskites, their reducibility in hydrogen, the ratio of Fe + Ni/La and the content of low bond oxygen forms on the sample surface. The correlation of activity and low bond oxygen forms was revealed, which is consistent with the mechanism of reaction of nitrous oxide decomposition. For future industrial applications the LaFe_0.4Ni_0.6O₃ perovskite is proposed due to its higher stability in the reaction medium as compared with samples with x > 0.6.