Self-assembled meso/macroporous phosphotungstic acid/TiO2 as an efficient catalyst for oxidative desulfurization of fuels

Hierarchically meso/macroporous phosphotungstic acid/TiO2 (HPW/TiO2) have been successfully synthesized by evaporation induced self-assembly method with polystyrene microspheres and block copolymer P123 as templates. The as-synthesized meso/macroporous HPW/TiO2 catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, nitrogen adsorption–desorption isotherms, Fourier transform infrared spectra and diffuse reflectance UV–Vis spectra. The results indicate that the catalysts possess disordered macropores and highly ordered mesopores, with Keggin type HPW embedded in the porous framework. The meso/macroporous catalysts exhibit excellent catalytic activity in oxidative desulfurization (ODS) of fuels. The catalytic performance of the meso/macroporous catalyst is markedly enhanced compared with that of pure mesoporous analogue under the same conditions. The high performance of the meso/macroporous catalyst should be attributed to the structural characteristics of meso/macopores, which improve the mass transfer and increase the accessible surface area of the catalyst. Moreover, the catalyst shows good recyclability, which makes it a promising catalyst in ODS process.