J.N. Díaz de León

Formation of Co-Promoted MoS2 Fullerene-Like Nanostructures on SBA-15 as Effective Hydrodesulfurization Catalyst

Cobalt-promoted MoS2 particles were synthesized on mesoporous SBA-15 and on a heteroatom (Al or Ti)-modified SBA-15 materials. The structural features of the materials were analyzed using X-ray diffraction (XRD), N2 adsorption–desorption measurements, UV–vis diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared (FTIR) spectroscopy of adsorbed NO, and high-resolution transmission electron microscopy (HRTEM). The formation of very well dispersed MoO3 nanoparticles over the walls of the modified SBA-15 nanostructure leads after sulfidation to MoS2 nano-slabs with a characteristic bent morphology, mostly fullerene-like. Moreover, results show that addition of Ti or even more of Al to the SBA-15 matrix allows stabilizing more dispersed Co-promoted MoS2 particles inside the mesoporous network. Combined, the stabilization effect induced by Ti or Al enhancing dispersion and the formation of curved morphologies lead to superior catalytic properties regarding activity and selectivity during the hydrodesulfurization of dibenzothiophene.Graphical Abstract

Oxidative dehydrogenation of n-octane over Mg-containing SBA-15 material

Abstract In this study, it is proposed the incorporation of MgO into of SBA-15 via the direct synthesis different atomic ratios of Si/Mg (20, 40 and 80). Although the incorporation of Mg did not affect the mesoporous character of SBA-based materials, it was found dramatic changes in the SBA-15 characteristic honeycomb structure even after the incorporation of small amount of Mg. The creation of more basic sites in SBA-15, because of the addition of Mg, improved ODH conversion of n-octane with respect to SBA-15, used as reference. Sample with a Si/Mg molar ratio of 20 showed the best catalytic performance in the oxidative dehydrogenation of n-octane, while the sample with a Si/Mg molar ratio of 40 achieve the highest productions of olefins.