Hydrodesulfurization of 4,6-DMDBT on a multi-metallic sulfide catalyst with layered structure

Hydrodesulfurization of 4,6-DMDBT on a Multi-metallic Sulfide Catalyst with Layered StructureA multi-metallic NiAlMoW catalyst with layered structure was prepared by surfactant-assisted co-precipitation method using NiAl-layered double hydroxide (NiAl-LDH) as the structure-directing template. By carefully tuning the composition of the layered structure and the synthesis conditions, we have prepared a series of Ni(m)Al(n)MoW catalysts. For the HDS of 4,6-DMDBT. NiAl(3)MoW-5 shows two times higher intrinsic catalytic activity (based on weight of active metals) compared to that of the commercial CoNiMoW/Al(2)O(3) catalyst. The sulfur content in the model compound could be reduced from 500 ppm to less than 20 ppm using this catalyst under the operation conditions of 3.0 MPa, 300 degrees C, a WHSV (weight hourly space velocity) of 9 h(-1), and H(2)/oil ratio of 800 Nm(3)/m(3). The synthesized catalysts were characterized by SEM. TEM, XRD, TG/DSC, nitrogen adsorption/desorption isotherms and XRF. This NiAlMoW catalyst has retained the unique layered structure of NiAl-LDH, which can facilitate uniform dispersion of the active species on both the surface and the edge of the layer. It was found that the layered structure has a great impact on the catalytic activity of the HDS reactions. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved