Synthesis of NiMo Catalysts Supported on Gallium-Containing Mesoporous Y Zeolites with Different Gallium Contents and Their High Activities in the Hydrodesulfurization of 4,6-Dimethyldibenzothiophene

Abstract

Mesoporous MY-xGa zeolites exhibiting both crystallized pore walls and narrowly dispersed mesopores with different Ga content were successfully synthesized. The synthesized samples were characterized by XRD, N 2 adsorption desorption isotherms, SEM, TEM, XPS, FTIR, 29 Si MAS NMR, 71 Ga MAS NMR, and Py-FTIR methods. The results show that the synthesized samples exhibit unique open channel like mesopore systems and outstanding crystallite natures; no nonframework Ga species were observed over the MY-xGa series samples, and their acidic properties can be modulated by varying the Ga/Al ratio in the initial synthesis gel. The corresponding NiMo/HMY-xGa catalysts were prepared via the incipient wetness coimpregnation method; the morphologies of the sulfide catalysts were characterized by HRTEM, and the covalent states of the active metals were characterized by XPS. The catalytic activities of the investigated catalysts for the 4,6-DMDBT HDS reaction were assessed, and the collected products were analyzed by GC and GC-MS methods. The catalyst NiMo/HMY-0.5Ga showed the highest catalytic activity due to the synergistic effect of modulated acidic properties, excellent morphology, highest sulfidation degree, and proper proportion of NiMoS phase. More importantly, 4-MDBT, DBT, and BP were observed and identified as the products of the 4,6-DMDBT HDS reaction, designated as the demethylation pathway (DM) for the 4,6-DMDBT HDS reaction. Finally, a reaction network including DDS, HYD, ISO, and DM pathways for the 4,6-DMDBT HDS reaction over catalyst NiMo/HMY-0.5Ga was proposed.

Synthesis of Ni-Modified ZSM-5 Zeolites and Their Catalytic Performance in n-Octane Hydroconversion

“…However, the amount of LAS (both the weak and strong acid sites) increased sharply after the introduction of 1 wt.% nickel by the impregnation method (from 22.57 to 104.5 µmol•g −1 ) and increased slightly with the further introduction of nickel to 2 wt.% (from 104.5 to 111.5 µmol•g −1 ). This result can be explained by the fact that BAS are only generated from framework Al species in the zeolites; the impregnation solution of nickel nitrate was acidic, so the process of impregnation led to dealumination from ZSM-5 zeolite frameworks and thus decreased the BAS (Fricke et al, 2000;Zhou et al, 2017b). Furthermore, some LAS can be formatted in the NiO granular (Zhou et al, 2017a).…”

Highly active P-doped sulfided NiMo/alumina HDS catalysts from Mo-blue by using saccharose as reducing agents precursor

“…Alumina and SA(0) materials had type H1 hysteresis characterizing solids with porous networks of uniform size and shape [42] where capillary condensation [43] started at ∼P/P s = 0.45. On the other hand, in SA-modified solids the hystheresis shape progressively shifted to H3 type suggesting presence of slit-shaped pores of non-uniform size and/ or shape [42] that could be provoked by pore mouth narrowing [44].…”

Selective hydrocracking of light cycle oil into high-octane gasoline over bi-functional catalysts

“…The binding energies for sulfide Mo 3d5/2 species, including Mo 6+ (MoO 3 ), Mo 5+ (oxysulfide), Mo 4+ (MoS 2 ) were 233.0 ± 0.3 eV, 230.7 ± 0.3 eV and 229.4 ± 0.3 eV, respectively. Moreover, the peak at 226.0 ± 0.3 eV could be assigned to S2s [38]. The binding energies ascribed to Mo 3d3/2 species were fixed at adding 3.1 eV based on Mo 3d5/2 species.…”