Oxidative desulfurization of fuels at room temperature using ordered meso/macroporous H3PW12O40/SiO2 catalyst with high specific surface areas

Abstract

Ordered meso/macroporous H3PW12O40/SiO2 nanocomposites with high specific surface areas were prepared using cationic surfactant and monodispersed polystyrene spheres (PS) as dual-template. The characterization results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, and small-angle XRD patterns confirmed the existence of ordered meso/macroporous structure and the wide-angle XRD patterns, Fourier transform infrared spectroscopy (FTIR), X-ray photoemission spectroscopy (XPS) measurements suggested the high dispersivity of the Keggin-type heteropolyacid (HPA) on silica matrix. There was an optimum value of cationic surfactant usage and proper calcination temperature of ordered meso/macroporous H3PW12O40/SiO2 catalyst leading to ultra-high specific surface areas. Furthermore, the ordered meso/macroporous H3PW12O40/SiO2 catalyst was evaluated for ultra-deep oxidative desulfurization (ODS) of cyclic sulphur-containing compounds using hydrogen peroxide (H2O2) as oxidant. Under optimum reaction conditions, dibenzothiophene (DBT) could be removed within 100 min at 30 °C by meso/macroporous H3PW12O40/SiO2 catalyst. The excellent catalytic activity should be attributed to the combination of ordered meso/macroporous architecture and high surface area of H3PW12O40/SiO2 catalyst which promoted the mass transport of reactants and products in the pore channel and provided more accessible catalytic active sites. In addition, the meso/macroporous H3PW12O40/SiO2 catalyst showed good stability with only 1.9% efficiency decreased after 6 cycles. Keywords: Ordered meso/macroporous structure, Phosphotungstic acid, Oxidative desulfurization, Room temperature