Formation of high surface-area yttrium oxide by the thermal decomposition of different inorganic precursors

Abstract

Y(CH 3COO) 3 · 4H 2O, Y(NO 3) 3 · 5H 2O and Y 2(C 2O 4) 3 · 8H 2O were used as precursor compounds for the formation of Y 2O 3 at 100–700°C. Thermal events occurring during the decomposition courses were monitored by means of TG and DTA. Intermediates and final solid products were characterized using infrared spectroscopy and X-ray diffractometry. The Y 2O 3 residues thus formed were subjected to surface and texture investigations. The results indicate that Y(NO 3) 3 · 5H 2O is completely decomposed at 450°C via different unstable intermediates to give high surface area (58 m 2 g −1) Y 2O 3. Both Y(CH 3COO) 3 · 4H 2O and Y 2(C 2O 4) 3 · 8H 2O are completely decomposed at 650°C via Y 2O 2CO 3 intermediate. However, Y(CH 3COO) 3 · 4H 2O yields a higher surface-area Y 2O 3 product (55 m 2 g −1) than Y 2(C 2O 4) 3 · 8H 2O (12 m 2 g −1).