Microstructure of La-modified Al₂O₃ support with LaAlO₃ nano-particles

Abstract

Lanthanum modified γ-alumina support that embedded highly dispersed LaAlO₃ nano-particles in γ-alumina matrix were prepared by an impregnation process using aqueous lanthanum (III) nitrate. 5 mol% La added alumina was heated in the temperature range of 600-1200°C and characterized by surface area measurement, X-ray powder diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The added lanthanum should react with γ-Al₂O₃ to form LaAlO₃ nano-particles in the secondary particle of alumina. LaAlO₃ nano-particles with an average crystallite size of about 11 nm were found after heat treatment at 800°C, and the crystallite size of LaAlO₃ nano-particles increased with the rise of heat treatment temperature.