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

Abstract

This article reports a novel strategy for preparing NiMo/γ-Al2O3 ultradeep hydrodesulfurization (HDS) catalysts via thermal decomposition of layered double hydroxides (LDHs). Ni–Al–[C6H4(COO)2]2–-LDHs/γ-Al2O3 (terephthalate-pillared Ni–Al-LDHs/γ-Al2O3) composites were first obtained by in situ crystallization of Ni–Al–[C6H4(COO)2]2–-LDHs on the surface of γ-Al2O3. Then Ni–Al–Mo7O24 6–-LDHs/γ-Al2O3 composites were synthesized from the above composites by the anion exchange of [C6H4(COO)2]2– with Mo7O24 6–. Finally, bimetallic Ni–Mo/γ-Al2O3 catalysts were obtained by the subsequent decomposition of Ni–Al–Mo7O24 6–-LDHs/γ-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 light on the industrial preparation and application of NiMo/γ-Al2O3 catalysts.

A Highly Active NiMoAl Catalyst Prepared by a Solvothermal Method for the Hydrogenation of Methyl Acrylate

“…In addition, flake-flower architectures formed under a high content amount of nickel (49-52 wt.%) when the MoO 3 content was below 7 wt.%, and the Mo-Ni/ASA catalyst displayed a two times higher yield than a commercial NiMoP/Al 2 O 3 due to the higher Ni dispersion [16]. Lv et al demonstrated that the Ni-Mo/γ-Al 2 O 3 catalyst prepared by the thermal decomposition of the layered double hydroxides Ni-Al-[C 6 H 4 (COO) 2 ] 2− -LDHs/γ-Al 2 O 3 showed a better dispersion of the NiO and MoO 3 on the alumina surface, and the yield of the catalyst increased by 20% more than the catalyst prepared by an impregnation method, while the preparation process was complicated and required a long time [17]. Past research has demonstrated that the dispersion of the active species can be improved by optimizing the catalyst preparation method.…”

High Metal–Acid Balance and Selective Hydrogenation Activity Catalysts for Hydrocracking of 1-Methylnaphthalene to Benzene, Toluene, and Xylene

“…Many studies have aimed at exploring highly dispersed metal catalysts. Several methods, such as deposition–precipitation, − equilibrium deposition filtration, − and chemical vapor deposition, and sonochemical, , have been developed. However, the well dispersed metal catalyst has a major drawback.…”

Sacrificial carbonaceous coating over alumina supported Ni–MoS2 catalyst for hydrodesulfurization

“…[8][9][10] However, the conventional alumina interact strongly with metal oxide precursors to form species that are hard to be reduced or sulded. [11][12][13] Towards this, various new support materials are introduced for HDS catalysts. Those carbon-based materials, such as active carbon or graphene with hierarchical structures and high surface area, seem to be promising support materials in hydrotreating reactions of heavy crude oil.…”