Ce0.9(Mg,Ni)0.1O2: Composite or Solid Solution

Abstract

Samples of the composition Ce0.9(Mg1 – xNix)0.1O2 (0 ≤ x ≤ 1, step x = 0.1) have been obtained by gel combustion followed by hydrothermal treatment. X-ray powder diffraction data have showed that after gel combustion and annealing at 1100°C, composite CeO2 (fluorite structure)/solid solution Mg1 – xNixO (halite structure) is formed, and additional hydrothermal treatment followed by annealing promotes the formation of limited solid solution Ce0.9(Mg1 – xNix)0.1O2. According to the results of IR spectroscopy, the CeO2/Mg1 – xNixO composite does not adsorb CO2 even in the presence of water vapor, which is also confirmed by diffuse reflectance spectra in the UV-visible region. On the contrary, the Ce0.9(Mg1 – xNix)0.1O2 solid solution absorbs CO2, as evidenced by the results of IR spectroscopy and thermogravimetric analysis.