Modulating the active phase structure of NiMo/Al₂O₃ by La modification for ultra‐deep hydrodesulfurization of diesel

Abstract

Herein, a series of mesoporous NiMo/LaAlO x with various La contents were constructed through a solvent evaporation-induced self-assembly protocol, and their catalytic activities were investigated for hydrodesulfurization (HDS) of 4,6-DMDBT.It has been confirmed that the incorporation of La influences the electronic structure and morphology of NiMoS active phase. The lower amount of La (x ≤ 1.0 wt.%) could facilitate the formation of "Type II" NiMoS phase by weakening the interaction of Mo-O-Al leakage and promoting the sulfidation of both Mo and Ni species as well as increasing the ratio of "Type II" NiMoS phase, thereafter boosting the HDS performances. Further increasing La incorporation, however, leads to the generation of inactive NiS x phase and decrease of NiMoS active phase proportion, the HDS activities of corresponding catalysts were suppressed. NiMo/LaAlO x -1.0 exhibits the highest activity for 4,6-DMDBT HDS because of its moderate metal-support interaction, optimal morphology and the largest proportion of "Type II" NiMoS active phase.

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

“…Wherein, the peak centered at ∼420 °C is associated with the reduction of MoO 3 to MoO 2 , while the peak located at ∼750 °C is attributed to the reduction of MoO 2 to Mo. 10,13 Noticeably, compared to the NiMo/Al 2 O 3 powder catalyst, the H 2 consumption peak at high temperature reflecting the strong MSI shifts toward the lower temperature for the 3D-NiMo/ Al 2 O 3 sample. It further confirms the weaker MSI on 3D-NiMo/Al 2 O 3 than that of NiMo/Al 2 O 3 , which matches well with NH 3 -TPD and in situ DRIFTS analyses.…”

“…Hitherto, Ni­(Co)­Mo­(W)/γ-Al 2 O 3 is still the commercially and widespread employed HDS catalyst by virtue of its relatively high catalytic HDS activity, low price, outstanding stability, and peerless mechanical property. − However, it requires more stringent conditions, for instance, high operation temperature and H 2 pressure, for this kind of HDS catalysts to realize ultra-deep removal of intractable aromatic hydrocarbon compounds, such as 4,6-dimethyldibenzothiophene (4,6-DMDBT), and produce ultra-clean fuels conforming with the strict regulations and/or specifications of diesel quality from increasingly lower quality raw petroleum feed-stocks. − Accordingly, the design and construction of more efficient HDS catalyst is regarded as the straightforward yet desirable choice for the oil refining enterprises. Nowadays, there are mainly three strategies, involving reaction condition adjustment, − active phase modulation, − and support regulation, − reported in literature to enhance HDS performance of Ni­(Co)­Mo­(W)/γ-Al 2 O 3 .…”

3D Printing Technique Fortifies the Ultradeep Hydrodesulfurization Process of Diesel: A Journey of NiMo/Al2O3-MMT

“…Furthermore, based on the information presented in 3 shows that pristine NiMo/Al 2 O 3 , similar to NiMo/Al 2 O 3 -MMT, presents two H 2 consumption peaks over the entire temperature range, which are attributed to the reduction of MoO 3 species to MoO 2 and, thereafter, the MoO 2 reduction to Mo. 23,38 In sharp contrast, with the introduction of MMT to NiMo/Al 2 O 3 , the higher reduction peak at above 700 °C on 3D-NiMo/Al 2 O 3 -MMT shifts noticeably toward the lower temperature (710 °C), notably lower than those of NiMo/Al 2 O 3 -MMT and NiMo/ Al 2 O 3 catalysts. It indicates a weaker MSI on it compared to that of the latter one.…”

Single Mo Atoms Stabilized on High-Entropy Perovskite Oxide: A Frontier for Aerobic Oxidative Desulfurization

“…In the past few years, sulfoxides (SO x ) originating from combustion of sulfur containing compounds in fossil fuels have caused severe environmental issues, which seriously affect the normal life and health of people. , Accordingly, strict laws and regulations have been issued by governments around the world to the regulate the sulfur contents in diesel . Nowadays, hydrodesulfurization (HDS) is the commercial and widely employed technology in industries to remove and/or convert the sulfur compounds, especially thiophene and mercaptan in the fuel product under both a high operating temperature (∼350 °C) and pressure (∼6 MPa). − However, it requires more stringent conditions to achieve ultra-deep removal of aromatic sulfides [dibenzothiophene (DBT) and its derivatives], which is cost ineffective to the manufacturing enterprise.…”