Layered Double Hydroxide Method for Preparing Ni-Mo/γ-Al2O3 Ultradeep Hydrodesulfurization Catalysts

This article reports a novel strategy for preparing NiMo/gamma-Al2O3 ultra-deep hydrodesulfurization (HDS) catalysts via thermal decomposition of layered double hydroxides (LDHs). Ni-Al-[C6H4(COO)(2)](2-)-LDHs/gamma-Al2O3 (terephthalate-pillared Ni-Al-LDHs/gamma-Al2O3) composites were first obtained by in-situ crystallization of Ni-Al-[C6H4(COO)(2)](2-)-LDHs on the surface of gamma-Al2O3. And then Ni-Al-Mo7O246--LDHs/gamma-Al2O3 composites were synthesized from the above composites by the anion exchange of [C6H4(COO)(2)](2-) with Mo7O246-. Finally, bimetallic Ni-Mo/gamma-Al2O3 catalysts were obtained by the subsequent decomposition of Ni-Al-Mo7O246--LDHs/gamma-Al2O3. The LDHs strategy imposes significant effects on improving the Ni/Mo dispersion with weak interaction of active metal and support, and thereby greatly improves the HDS properties of the resulting catalysts. The HDS assessment results revealed that the catalyst obtained by LDHs procedure exhibits outstanding HDS activities for 4,6-dimethyldibenzothiophene and Dagang FCC diesel. The novel strategy employed in this article sheds a light on the industrial preparation and application of NiMo/gamma-Al2O3 catalysts.