FORMATION OF HIGH-SURFACE-AREA YTTRIUM-OXIDE BY THE THERMAL-DECOMPOSITION OF DIFFERENT INORGANIC PRECURSORS

Y(CH3COO)(3) . 4K(2)O, Y(NO3)(3) . 5H(2)O and Y-2(C2O4)(3) . 8H(2)O we re used as precursor compounds for the formation of Y2O3 at 100-700 de grees C. Thermal events occurring during the decomposition courses wer e monitored by means of TG and DTA. Intermediates and final solid prod ucts were characterized using infrared spectroscopy and X-ray diffract ometry. The Y2O3 residues thus formed were subjected to surface and te xture investigations. The results indicate that Y(NO3)(3) . 5H(2)O is completely decomposed at 450 degrees C via different unstable intermed iates to give high surface area (58 m(2) g(-1)) Y2O3. Both Y(CH3COO)(3 ) . 4H(2)O and Y-2(C2O4)(3) . 8H(2)O are completely decomposed at 650 degrees C via Y2O2CO3 intermediate. However, Y(CH3COO)3 . 4H(2)O yield s a higher surface-area Y2O3 product (55 m(2) g(-1)) than Y-2(C2O4)(3) . 8H(2)O (12 m(2) g(-1)).