One-Pot Three-Dimensional Printing of a Hierarchical NiMo/Al₂O₃ Monolithic Catalyst for 4,6-Dimethyldibenzothiophene...

The development of a competitive-cost and high-efficiency NiMo/Al₂O₃ hydrodesulfurization (HDS) catalyst remains challenging in the field of petrochemical industry. Herein, a highly efficient NiMo/Al₂O₃ monolithic HDS catalyst was elaborately designed and successfully fabricated via a one-pot three-dimensional (3D) printing strategy, and its HDS activity was examined for 4,6-dimethyldibenzothiophene conversion. The results unveil that the NiMo/Al₂O₃ monolithic catalyst prepared by the 3D printing strategy (3D-NiMo/Al₂O₃) exhibits hierarchical structure due to the combustion of hydroxymethyl cellulose serving as adhesive, which endows the weaker metal-support-interaction between Mo oxides and Al₂O₃, remarkably promoting sulfidation of both Mo and Ni species and the formation of "Type II" NiMoS active phase, thereby reducing the apparent activation energy (E_a = 109.2 kJ·mol^-1) and increasing the catalytic activity (TOF = 4.0 h^-1) and thereafter dramatically boosting the HDS performance of 3D-NiMo/Al₂O₃ compared with that of NiMo/Al₂O₃ (E_a = 150.6 kJ·mol^-1 and TOF = 2.1 h^-1) counterpart synthesized by conventional method with P123 serving as the mesoporous template. Therefore, this study offers a facile and straightforward strategy to fabricate an efficient HDS catalyst with hierarchical structures.