Influence of Fuel Type on Ultrasonic-assisted Combustion Synthesis of NiMo/Al2O3 Catalyst for Hydrodesulfurization of Thiophene

Various organic fuels, including citric acid, ethylene glycol, glycine and urea, were used to synthesize alumina-supported NiMo catalysts via the solution combustion method and applied in thiophene hydrodesulfurization at atmospheric pressure. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDX), Nitrogen adsorption/desorption, and Temperature program reduction (TPR). The results showed that the type of organic fuel has a considerable effect on the phase structure, surface morphology and reducibility potential due to the different amounts of heat and gaseous products released during the combustion reaction. Also, a relatively homogeneous distribution of the metals over support was obtained in all samples. The highest activity was obtained over a sample synthesized with citric acid as fuel due to its significant proper-ties, such as high surface area, considerable surface pore structure, and weakened metal-support interaction, compared with other fuel additives. Activity assessment of the prepared catalyst by ethylene glycol and glycine demonstrated that 100% abatement of thiophene was achieved at 105 °C and 30 min.