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Abstract: Phosphate-loaded mesoporous SBA-15 and SBA-16 materials were used as supports of novel ternary Co-Mo-W hydrodesulfurization catalysts. The effects of support morphology (SBA-15 against SBA-16) and its modification with variable amounts of phosphorus were studied. The sulfided catalysts were tested in a reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT) at 350°C and 3.1MPa of total H2 pressure. The calcined, fresh sulfided and spent catalysts were characterized by a variety of techniques (N2 adsorption–desorption isotherms, XRD, TPR, TPD-NH3, DRS UV–vis, micro-Raman spectroscopy, XPS, HRTEM and TPO/TGA). Regardless of the support, it was found that the presence of phosphorous inhibited the HDS activity, and the catalytic response of both SBA-15- and SBA-16-based systems did not depend on the support morphology. In terms of the reaction rate constants (k), both CoMoW/SBA-15 and CoMoW/SBA-16 catalysts were more active than a CoMo/Al2O3 commercial catalyst containing a small amount of phosphorous in its formulation. In general, the spent CoMoW/(x)P-SBA-16 catalysts showed a lower coke formation than their SBA-15-based counterparts because the phosphate incorporation to the SBA-16 material led to decrease in coke formation in the final catalysts, as opposite to the behavior of SBA-15-based counterparts. [Copyright &y& Elsevier]

A group of hydrodesulfurization (HDS) catalysts, based on transition metal sulfides (Co-Mo-W) and supported on mechanically-mixed mesoporous silicas (SBA-15 and SBA-16), have been synthesized and characterized by physicochemical methods (DRS-UV–vis, Micro Raman spectroscopy, XRD, SEM, HRTEM, EDS and catalytic activity). It has been demonstrated that the use of a mixture of silicas with two different porous structures has an advantage with respect to the use of the SBA-15 and SBA-16 separately for the preparation of supported catalysts for hydrodesulfurization reactions of refractory sulfur compounds, such as dibenzothiophene. This is because the presence of different porous structures has a positive effect over the diffusion processes of the precursors of the active phases on the support, and the whole result is a higher catalytic activity for the HDS reactions of dibenzothiophene, even more than that of the commercial catalyst used as a comparative model; this activity is also related with the stage of the synthesis process in which the mixture is done. [ABSTRACT FROM AUTHOR]