Thermal stability and properties of Pd/CeAlO.sub.3 catalyst prepared by combustion synthesis

Synthesis and properties of cerium aluminate catalyst were investigated. The catalyst was prepared via combustion synthesis involving aluminum and cerium nitrates and glycine in the presence of palladium chloride. The obtained material was investigated using X-ray diffraction, Fourier transformed infra-red spectroscopy, differential thermal and thermo-gravimetric analysis, N.sub.2 adsorption, Raman spectroscopy, scanning electron microscopy, energy dispersion X-ray spectroscopy and X-ray photoelectron spectroscopy. Catalytic activity was tested for the toluene oxidation process. The direct product of combustion synthesis was CeAlO.sub.3 which remained stable even after thermal treatment at 400 °C for 2 h in static air, while temperature treatment at 800 °C for 2 h resulted in the decomposition of CeAlO.sub.3 into CeO.sub.2 and [gamma]-Al.sub.2O.sub.3. Both thermal treatment products had sponge-like microstructure, but relatively small specific surface areas. Nevertheless, CeO.sub.2 prepared at 800 °C was nanocrystalline. Palladium was present as oxide homogeneously dispersed throughout the catalyst. The prepared catalyst proved to be highly active for the toluene oxidation process.