Effect of temperature and precursor concentration on the morphology of Cu/γ-Al2O3 prepared via urea combustion method

Abstract

Mesoporous gamma alumina (γ-Al2O3) was successfully prepared via urea route synthesis. Different urea concentration effects were investigated toward the material’s characterization. Calcination was done at 500 °C for 3 h to obtain γ-Al2O3. Fourier transform infrared spectroscopy (FTIR) analysis showed that the urea was decomposed completely after calcination. The amorphous gamma phase of alumina was transformed completely into crystalline alpha phase, accompanied by a lower surface area of alumina at a higher concentration of urea. Copper was added by wet impregnation and the γ-Al2O3 was then calcined at different temperatures to study the effect on the material’s properties. X-ray diffractometer (XRD) characterization showed peaks that belong to CuO and CuAl2O4. As the calcination temperature rose, the peak intensity of the CuAl2O4 became higher. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that CuO nanoparticles covered the surface of the γ-Al2O3. The absence of a γ-Al2O3 diffraction peak was due to its low crystallinity.