Formation of featured nano-structure in thermal stable La-doped alumina composite catalyst

Nanometer-order structural changes of lanthanum-modified γ-alumina at elevated temperature were examined for application toward heat-stable catalytic support. The composite powder was prepared by aqueous process using lanthanum (III) nitrate and alumina. The La added aluminas were heated in the temperature range of 600–1200 °C, and then characterized by surface area measurement, X-ray powder diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The solid-state reaction between lanthanum oxide and alumina lead to the nano-structure where the nanometer-size particles of LaAlO3 are dispersed in the secondary particles of alumina. The tailored microstructure provides a new nano-structured catalyst of La-alumina, which is stable catalytic support at high temperatures.