Acidic sites and deep desulfurization performance of nickel supported mesoporous AlMCM-41 sorbents

Nickel particles supported on mesoporous MCM-41 or AlMCM-41 (SiO2/Al2O3 = 30, 50) sorbents were prepared by an incipient wetness impregnation (IWI) of nickel nitrate and the ultra-deep desulfurization properties for model fuels or diesel were evaluated under ambient conditions. Among the tested sorbents, 15%Ni-AlMCM-41 (30) presented the highest sulfur adsorption capacity toward thiophene, benzothiophene and commercial diesel. The pore structure, acidic sites and surface features of the sorbents were characterized by means of BET, XRD, NH3-TPD, Py-FT-IR and XPS techniques, it revealed that Lewis acidic sites played important role in the removal of organic sulfur compounds over reduced 15%Ni-AlMCM-41 (30). After regeneration of used sorbent, approximately 100% of organic sulfur adsorption capacity was recovered.

► NH3-TPD and Py-FT-IR spectra verified that the addition of nickel and aluminum enhanced remarkably Lewis acid sites.
► Higher breakthrough sulfur capacity correlated with more acidic sites.
► Presence of aromatic compounds in diesel reduced the adsorption of thiophene and derivatives.