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Trimetallic NiCoMo catalysts supported on γ-alumina (γ-Al2O3), amorphous silicon dioxide (SiO2), and mesostructured silicate (SBA-15) with equal surface concentration of active components were synthesized, and their physicochemical characteristics, including the morphology of the active phase particles, were studied. The performance of the synthesized catalysts in target hydrotreating reactions at different concentrations of an organic nitrogen-containing inhibitor, quinoline (0–1000 ppmw nitrogen), was determined. The inhibiting effect of quinoline on the hydrodesulfurization and hydrogenation reactions occurring on the synthesized catalysts and the influence of the kind and properties of the support on this effect were evaluated.

Demetallization of a mixture of vacuum gas oil with heavy coker gas oil on CoMo/γ-Al2O3 catalysts with different pore structures was studied, and the influence of the catalyst pore structure on the process results was demonstrated. For the demetallization catalysts to be effective, their pore size should be restricted not only from below but also from above. When using samples with broad pores, effects of the hydrodesulfurization and hydrodemetallization inhibition can arise owing to adsorption of supramolecular structures of heavy residues, in particular, of asphaltenes.

The effect of quinoline on the hydrodesulfurization and hydrogenation activities of bi- and trimetallic NiMo(W)/Al2O3 hydrotreating catalysts obtained using Keggin heteropoly acids H4SiMo3W9O40, H4SiMo12O40, and H4SiW12O40 (denoted as SiMo3W9, SiMo12, and SiW12, respectively) and a mixture of two monometallic heteropoly acids (SiMo12 and SiW12) was studied. The catalytic properties were determined in a fixed-bed microreactor in hydrotreating of model feedstock containing dibenzothiophene and naphthalene and of the same feedstock with the addition of quinoline. The trimetallic NiMoW/Al2O3 sample based on the mixed SiMo3W9 heteropoly acid exhibited 1.5 times higher catalytic activity in all the reactions studied compared to its analog prepared from a mixture of SiMo12 and SiW12 heteropoly acids with the same metal ratio. The trimetallic NiMoW/Al2O3 catalyst based on the mixed SiMo3W9 heteropoly acid surpassed in the activity the NiMo/Al2O3 sample and was more resistant to the inhibiting effect of quinoline than its analog prepared from a mixture of the two heteropoly acids. The correlations of the inhibiting effect of quinoline with the morphology of the active phase particles and the content of promoted active sites Ni(Mo)WS in the bi- and trimetallic NiMo(W)/Al2O3 catalysts were found.

СоМоS/Sup catalysts were prepared from 12-molybdophosphoric heteropoly acid and cobalt citrate, with Al2O3, SiO2, TiO2, and ZrO2 used as supports (Sup). The synthesized catalysts were studied by low-temperature nitrogen adsorption, X-ray diffraction, temperature-programmed ammonia desorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The catalytic properties of the catalysts were studied in a flow-through installation at 260 and 340°С, pressure of 3.0 MPa, feed space velocity of 80 h–1, and Н2/feed ratio of 500 Ln.c. L–1. The guaiacol hydrodeoxygenation rate increases with a decrease in the mean length of the active phase particles, irrespective of the kind of the oxide support. As for the support effect, the catalyst activity decreases in the order SiO2 > Al2O3 > ZrO2 ~ TiO2. On the other hand, the catalysts supported on ZrO2 and Al2O3 exhibit the highest stability. The causes of the observed trends and the possible relationships between the characteristics of the catalysts and active phase nanoparticles are discussed.

Trimetallic NiMoW/Al2O3 catalyst was prepared using mixed H4SiMo3W9O40 heteropoly acid of Keggin structure and nickel citrate. Bimetallic NiMo/Al2O3 and NiW/Al2O3 catalysts based on H4SiMo12O40 and H4SiW12O40, respectively, were synthesized as reference samples. The use of mixed H4SiMo3W9O40 heteropoly acid as an oxide precursor allows the tungsten sulfidation degree and the degree of promotion of active phase particles to be increased. The hydrodesulfurization activity is enhanced as compared to NiW/Al2O3 catalyst. The synergistic enhancement of the activity of the NiMo3W9/Al2O3 catalyst relative to the bimetallic analogs is probably caused by formation of new mixed promoted active sites for direct desulfurization.