“Nanowire catalysts for ultra-deep hydro-desulfurization and aromatic hydrogenation”

• Used single crystal ZnO nanowire powders as catalyst support for nickel.
• The catalysts exhibited high activity towards ultra-deep hydro-desulfurization.
• The catalysts showed high activities of both ultra-deep hydro-desulfurization and aromatic hydrogenation.
• The high resolution TEM, XRD and X-ray Photoelectron Spectroscopy results suggest sulfur is associated with Zn.
• Efficient transfer of sulfur from active Ni rich NixZny clusters to ZnO nanowires.

Here, we report high performance catalysts designed using nanowire supports. Specifically, nickel clusters supported on Zinc Oxide (ZnO) nanowires and γ-alumina found to be highly active for ultra-deep desulfurization and aromatic hydrogenation of diesel. They were also found to be highly active for ultra-deep desulfurization of gasoline and kerosene. The catalysts reduced sulfur from diesel, gasoline, and kerosene fuels containing sulfur as high as approximately 200 ppm to less than 1 ppm with sustained activity over testing periods of 100–150 h. The feed contained some of the most difficult to remove sulfur compounds such as 4-methyldibenzothiophene (MDBT), 4,6-dimethyldibenzothiophene (DMDBT). In addition to activity towards ultra-deep desulfurization, these catalysts have shown to be active towards saturate/hydrogenate aromatics in diesel at moderate reaction conditions (30 bar, 290 °C, and LHSV 2.2 h−1). The active catalytic site was determined to be a super Ni rich NixZny phase which seemed to remain essentially sulfur free during the reaction. The regenerated catalyst showed reasonable activity toward desulfurization of gasoline.

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