Hybrid plasma-sono-coprecipitation dispersion of NiMo nanocatalyst over functionalized multiwall carbon nanotube used in hydrodesulfurization of thiophene

To evaluate the effect of non-thermal plasma and ultrasound treatment on the catalytic physicochemical properties and hydrodesulfurization activity, a series of NiMoW/FMWCNT nanocatalysts (4%NiO, 12%MoO₃, and 6% WO₃) were prepared via co-precipitation method. The co-precipitated and treated by ultrasound or plasma-ultrasound nanocatalysts were characterized using XRD, FESEM, EDX dot-mapping, BET and FTIR techniques. The XRD data confirmed the formation of NiO, WO_3, and Mo₂C as the crystalline phase on carbon support. The results indicated ultrasound irradiation and non-thermal plasma treatment have significant influences on phase structure, morphology, and surface area. The optimum amount of applied voltage of plasma was found to be 500?V in which the maximum surface area and well-dispersion of the active phase were found. Further applied plasma voltage led to a decrease in catalytic activity due to the higher support-metal interaction and unpleasant distribution of the particles on nanocatalyst surface. The plasma–ultrasound hybrid synthesis method was able to eliminate 100% of sulfur in the initial solution of thiophene during hydrodesulfurization process.