A cost-effective preparation method of Ba-hexaaluminate nanoparticles for catalytic combustion of methane

The rod-like hexaaluminate nanoparticles have been prepared by using the alumina sol as the (NH4)2CO3 co-precipitation precursor and supercritical drying (SCD) method. Formation of the final hexaaluminate likely occurs via diffusion of the Ba2+ ions into the δ-Al2O3 matrix. Only Ba-hexaaluminate phase (alumina-rich phase) is observed in the hexaaluminate products. Since the network of the aerogel has a higher stability than that formed by using aluminum nitrate, leading to the decrease in the mobility of aluminum at high calcination temperature, which plays a significant role in maintaining high surface area and pore structure.