Hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene over NiMo supported on yolk-shell silica catalysts with adjustable shell thickness and yolk size

Ke Yu, Weimin Kong, Zhen Zhao, Aijun Duan, Lian Kong, Xilong Wang

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Mesoporous yolk-shell silica spheres with different shell thicknesses and yolk sizes (YxSy) were synthesized by incubating mesostructured silica nanospheres with water. Al-modified YxSy-supported NiMo catalysts were prepared and applied to hydrodesulfurization (HDS) of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The shell thickness and yolk size have a large effect on the HDS activities. Among the as-made catalysts, NiMo/Al-Y30S13 catalyst with relatively low shell thickness (13 nm), yolk size (30 nm) and proper structural stability exhibit the highest activities for HDS of DBT and 4,6-DMDBT at the weight time of 1.39–13.76 g min mol−1, of which its DBT conversion at 1.39 g min mol−1 (50.4%) is 1.5 times as that of the reference NiMo/Al2O3 (33.6%), four times as that of NiMo/Al-Y83S28 (12.3%) and what's more, the HDS conversion of Al-Y30S13 could reach 99.5% at 13.76 g min mol−1 (about 2.5 ppm S remained). Its 4,6-DMDBT conversion at 1.39 g min mol−1 (27.1%) is almost 2 times as that over NiMo/Al2O3 (13.8%), and 2.7 times as that over NiMo/Al-Y83S28 (9.9%). Additionally, the 95.7% HDS conversion (about 16.6 ppm S remained) of Al-Y30S13 could be obtained at 13.76 g min mol−1. The good HDS performance of the NiMo/Al-Y30S13 catalyst could be derived from the synergistic effect of moderate shell thickness and relatively small yolk size, proper structural stability, appropriate acidity, moderate metal-support interaction (MSI), suitable dispersion and desirable stacking morphology of the Ni and Mo species. DBT HDS over the NiMo/Al-Y30S13 catalyst shows the lowest direct desulfurization (DDS)/hydrodesulfurization (HYD) ratio (2.70), demonstrating that the increase of HYD proportion could improve the ability of ultra-deep desulfurization of catalysts. 4,6-DMDBT HDS over the NiMo/Al-Y30S13 catalyst shows the highest selectivity of isomerization (ISO) route (69%), illustrating that the ISO route is the dominant pathway. Furthermore, the mechanisms of DBT and 4,6-DMDBT HDS are proposed over NiMo/Al-YxSy materials.
Original languageEnglish (US)
Pages (from-to)128-143
Number of pages16
JournalJournal of Catalysis
Volume410
DOIs
StatePublished - Apr 27 2022

Bibliographical note

KAUST Repository Item: Exported on 2022-05-13
Acknowledgements: Financial supports from the National Science Foundation of China (U1908204, 91845201, and 22002093), Scientific Research Project of Education Department of Liaoning Province (LQN202006) and King Abdullah University of Science and Technology (KAUST).

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry

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