RESUMO
Nanocrystalline Fe2O3-NiO composite catalysts were prepared using a sonication-assisted green preparation method. The prepared catalysts were characterized using different techniques, including thermal analyses (TGA/DTA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, surface area measurements (SBET), and scanning electron microscopy (SEM). The surface basicity of the prepared catalysts was measured using the temperature-programmed desorption of CO2 (CO2-TPD) as a highly acidic probe molecule. The catalytic activity of all the prepared catalysts was tested at a temperature range of 250-325 °C towards the dehydrogenation of 2-butanol to methyl-ethyl ketone (MEK), which is considered a promising fossil fuel alternative and has several industrial applications. The composite catalysts showed better catalytic activity compared to the pure oxides (i.e., Fe2O3 and NiO) due to the strong synergetic effect between the two oxides. Fe2O3 prevented the coke formation over the surface of NiO by the oxygen-scavenging effect of Fe, which promotes the oxidation of the carbonaceous species and increases the catalyst's resistance to deactivation. The effect of weight hourly space velocity (WHSV) on the catalytic activity was tested over a selected catalyst. In addition, the stability and durability of the catalyst were tested across four successive reaction cycles, demonstrating remarkable performance throughout all the reaction cycles.