Synthesis and characterization of PWMn/NiO/PAN nanosphere composite with superior catalytic activity for oxidative desulfurization of real fuel

A new organic-inorganic hybrid material (PWMn/NiO/PAN) was successfully synthesized based on cesium salt of mono Mn (II)-substituted phosphotungstate Cs5PW11MnO39 (PWMn), nickel oxide (NiO), and polyaniline (PAN). The samples were characterized using FT-IR, UV-vis, XRD, SEM, and EDX techniques. Taking into account the analysis results, the phosphotungstate species were highly dispersed on the metal oxide and polymer matrix. Additionally, the PWMn/NiO/PAN composite was found in a nanoscale spherical shape with the main range particle size of 50-60 nm. Oxidative desulfurization (ODS) experiments were carried out for removal of sulfur-containing compounds in gasoline and model fuels. Compared with the catalytic activity of the bulk materials, the prepared PWMn/NiO/PAN nanosphere composite showed superior performance in the ODS system. According to the designed process, the sulfur compounds were oxidized in the presence of the catalyst by oxidant and then extracted from the fuel phase by extraction solvent. The ODS results revealed that the concentration of sulfur content of typical gasoline was lowered from 4989 to 133 ppm with 97% efficiency at 35 degrees C after 1 h. Also, the PWMn/NiO/PAN hybrid catalyst could be reused for five successive runs without any appreciable loss in its catalytic activity. The current research suggests that the PWMn/NiO/PAN nanosphere composite can represent a new promising class of organic-inorganic hybrid catalysts for ODS system.