Preparation and thermal stability of La2O3–Al2O3 aerogels from chemically modified Al-alkoxide

Abstract

La-doped Al₂O₃ aerogels (containing 0.5–10 mol% La₂O₃) were prepared using Al-alkoxide chemically modified with ethyl acetoacetate. The specific surface area of non-doped Al₂O₃ aerogels heat-treated at 1000 to 1200 °C was greatly increased by doping a small amount of La₂O₃ . X-Ray diffraction measurements showed that the crystalline phase of La-doped Al₂O₃ aerogels containing 1 mol% La₂O₃ heat-treated at 1200 °C for 2 h was θ-Al₂O₃ , while that of non-doped Al₂O₃ aerogels was α-Al₂O₃ . The La₂O₃–Al₂O₃ aerogels heat-treated at 1000–1200 °C showed the largest specific surface area at the composition of 1 mol% La₂O₃ with the presence of the θ-Al₂O₃ phase.