Single-Step Combustion Synthesis of Cerium Aluminate in the Presence of Copper

Cerium aluminate, CeAlO₃, was prepared in the presence of copper in a single-step combustion synthesis without the need for post-synthesis calcination. The prepared material was investigated using x-ray diffraction followed by whole powder pattern decomposition, scanning electron microscopy, energy-dispersive x-ray spectroscopy, Fourier-transformed infrared spectroscopy, UV–Vis spectroscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis. It was established that if the amount of copper was at least 1 mol.%, the combustion process was enhanced enough to result in the appearance of CeAlO₃ as the dominant phase. If the amount of copper was less than 1 mol.%, CeO₂ forms instead of CeAlO₃. The share of CeAlO₃ increases with the amount of copper, but this effect becomes negligible at 3 mol.%. Samples with CeO₂ as the main phase display a sponge-like morphology, while samples with CeAlO₃ as the main phase are dendritic. CeAlO₃ decomposes to CeO₂ and γ-Al₂O₃ between 600 and 800 °C yielding sample mass gain due to binding of additional oxygen in course of Ce³⁺-to-Ce⁴⁺ oxidation.