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Meso/microporous composite material KIT-5/Beta (KB) with a cubic Fm3m mesoporous structure and BEA microporous structure was successfully synthesized by an in situ assembly method. And the corresponding NiW/KB catalysts were prepared for the hydrodenitrification (HDN) reactions of quinoline. The supports and catalysts were characterized using XRD, FTIR, N2-adsorption, TEM, SEM, pyridine-FTIR, XPS and HRTEM techniques. The results revealed that the textural and acidic properties of the composite materials were dramatically improved in comparison to those of pure silica KIT-5. NiW/KB-3 displayed the highest HDN activity (97.44%) among all the catalysts, which was attributed to the synergistic effects of the open channel structure, excellent textural properties, suitable acidity, the best sulfidation and dispersion of active species, implying that KB-3 has potential application in HDN reactions. Moreover, the quinoline HDN reaction networks of the NiW/KB-x series are proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The interaction between copper and support was the strongest on the 10Cu/TS (Cl) catalyst. • The 10Cu/TS (Cl) catalyst obtained the most surface Cu+ species and the largest S Cu(I). • The conversion of methanol was proportional to the amount of all acid sites on the catalyst surface. • The carbonylation of methanol to MA on Cu/TS catalyst is a structure-sensitive reaction. In the present study, three kinds of copper/titania-silica mixed oxides (Cu/TS) catalysts were prepared using copper chloride, copper nitrate, and copper acetate as copper precursors by the sol-gel method. The catalytic performance was tested in the vapor phase carbonylation of methanol free of halide. The characterization results showed that the interaction between copper and support was the strongest on the 10Cu/TS (Cl) catalyst, leading to the highest copper dispersion and the most surface Cu+ species. As a result, the 10Cu/TS (Cl) catalyst obtained the largest absorption capacity of CO and the maximum amount of Lewis acid sites. The catalytic performance results showed that the space time yield (STY) of methyl acetate (MA) was positively correlated with the content of surface Cu+ species and the specific surface area of the Cu+ cations (S Cu(I)). Therefore, the 10Cu/TS (Cl) catalyst obtained the highest STY MA of 1.619 mol/h.kg cat. Moreover, the STY MA per Cu+ site was inversely proportional to the copper particle size, indicating that the carbonylation of methanol to MA is a structure-sensitive reaction. And the methanol conversion was positively correlated with the amount of surface acid sites. Furthermore, the active sites for the synthesis of methyl formate and dimethyl ether were also studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ring opening of decalin was studied over Ni-W catalysts with different pretreatment. • The catalyst activity has relation with the metal sites, the amount of the strong Brönsted acid sites and the surface area on the catalyst. Besides these, the catalysts deactivation also has the close relation with the coke produced on the catalyst during the reaction. • The sulfide catalyst might be more suitable for the industry because of its high reaction activity and stability. The bimetallic Ni-W oxide catalyst supported on USY- Al 2 O 3 has been prepared and converted into Ni-W sulfide, carbide and nitride catalysts. These four types of catalysts have been characterized by surface area measurements, pulsed CO chemisorption, thermogravimetric analysis, X-ray diffraction, temperature-programmed reduction and pyridine infrared spectroscopy. The initial decalin reaction activity of the catalysts decreases in the order of carbide catalyst > oxide catalyst > sulfide catalyst >> nitride catalysts. The catalysts deactivation decreases in the order of: sulfide catalyst > carbide catalyst >> nitride catalyst > oxide catalyst. The initial ring-opening activity decreases in the order of carbide catalyst > oxide catalyst ∼sulfide catalyst >> nitride catalyst. The catalyst activity has relation with the metal sites, the amount of the strong Brönsted acid sites and the surface area on the catalyst. Besides these, the catalyst deactivation also has the close relation with the coke produced on the catalyst during the reaction. [ABSTRACT FROM AUTHOR]

Pure KIT-5 and a series of Al-KT-X materials modified by different amounts of aluminum were synthesized by a direct hydrothermal method and acted as supports for the catalysts of a quinoline hydrodenitrification reaction with the NiW active phases supported. The results of X-ray diffraction (XRD), N2 isotherm absorption-desorption, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) for the supports indicated that Al species were embedded into the framework of the KIT-5 materials with a large pore size, pore volume, and specific surface area. The Pyridine-Fourier transform infrared spectroscopy (Py-IR) result of the catalysts demonstrated that the addition of aluminum atoms enhanced the acidity of the catalysts. The results of the high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectra (XPS) characterizations for the sulfide catalysts indicated that the embedded Al species could facilitate the dispersion of active metals and the formation of the active phases. Among all the catalysts, NiW/Al-KT-40 showed the maximal hydrodenitrogenation conversion (HDNC) due to its open three-dimensional pore structure, appropriate acidity, and good dispersion of active metals. [ABSTRACT FROM AUTHOR]