Insight of 1D γ-Al2O3 nanorods decoration by NiWS nanoslabs in ultra-deep hydrodesulfurization catalyst

• Published in: Journal of catalysis 2015-01, Vol.321, p.51-61
• Main Authors: Díaz de León, J.N., Zepeda, T.A., Alonso-Nuñez, G., Galván, D.H., Pawelec, B., Fuentes, S.
• Format: Article
• Language: English
• Subjects: 1D materials; 4,6′Dimethyl-dibenzothiophene; Alumina; Hydrodesulfurization; Nanorods; NiWS; Refining; Ultra-low sulfur diesel
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2014.11.001

[Display omitted] •1D-γ-Al2O3 nanorods were used to prepare a NiW hydrodesulfurization catalyst.•Highly distributed NiWS phases were located all over the alumina nanorods.•Ni-W-S sites could rather act as C–S bond hydrogenolysis.•NiWS type II nanoslabs in a tilted orientation were suggested. Novel 1D-γ-Al2O3 nanorods were used to prepare a NiW hydrodesulfurization catalyst. Acid/base measurements of the NiW/Al-catalyst revealed a mainly weak and lower acidity and a great quantity of Lewis sites in oxide/sulfided forms. HRTEM exposed a homogeneously distributed active phase all over the surface of the Al-nR supported catalyst. Marked differences on the stacking degree and slabs length were observed when compared both materials. The activity for NiW/Al-nR resulted higher than that obtained for NiWP/γ-Al2O3 catalyst. Even when both materials showed almost the same specific hydrogenation rate, the main change was the higher hydrogenolysis on the NiW/Al-nR catalyst. Theoretical calculations showed that 1T-S-W-S cluster with Ni on the top resulted with less metallic character than when Ni was modeled in a corner of a 2H-S-W-S 3D crystal. For that reason, it was proposed that Ni-W-S sites on small slabs could act rather as hydrogenolysis sites than as hydrogenation sites.