Effects of pH and chelating agent on the NiWS phase formation in NiW/γ-Al2O3 HDS catalysts

Ni‐W Catalysts Supported on HZSM‐5/HMS for the Hydrogenation Reaction of Aromatic Compounds: Effect of Ni/W Ratio on Activity, Stability, and Kinetics

“…The band around 250 nm are ascribed to an absorption associated with a charge transfer transition of O 2− –Ni 2+ and O 2 –W 6+ for NiO and polytungstate species, respectively. A shoulder at above 300 nm is observed that it is associated with the d–d transitions of Ni 2+ and probably the bulk WO 3 phase and part of the octahedral coordinated tungsten species . The changes in the intensities of the bands in the supported Ni and Ni‐W oxide catalysts' spectra may be due to the differences in the interaction strength of species and their population on the supports.…”

Structure and Quantification of Edge Sites of WS2/Al2O3 Catalysts Coupling IR/CO Spectroscopy and DFT Calculations

“…The CoMo and NiMo/Al 2 O 3 catalysts have been extensively studied, meanwhile NiW catalysts have remained less investigated . The importance of NiW/Al 2 O 3 sulfide catalysts is given by their excellent performance in hydrogenation reactions for deep HDS, providing a high potential for the conversion of alkyl‐dibenzothiophenes (alkyl‐DBTs) . HDS catalysts have been the subject of numerous characterization studies, and presently there is a general agreement that the sulfide phase MoS 2 (WS 2 ) presents a lamellar structure, formed by layers of MS 2 (M=W, Mo).…”

“…[1] The importance of NiW/Al 2 O 3 sulfide catalysts is given by their excellent performance in hydrogenation reactions for deep HDS, providing a high potential for the conversion of alkyl-dibenzothiophenes (alkyl-DBTs). [2,3] HDS catalysts have been the subject of numerous characterization studies, [4] and presently there is a general agreement that the sulfide phase MoS 2 (WS 2 ) presents a lamellar structure, formed by layers of MS 2 (M=W, Mo). The 2D morphology of these layers, their average stacking (~2 to 4) and their average size (~3 to 6 nm) depends on the sulfidation conditions, the metal loading among other parameters.…”

Facile fabrication, characterization and catalytic activity of a NiMo/Al2O3 nanocatalyst via a solution combustion method used in a low temperature hydrodesulfurization process: the effect of fuel to oxidant ratio

“…5,6 Generally, hydrotreating reactions are catalyzed by molybdenum/tungsten disulde and promoted with cobalt/ nickel, which is placed at the edge of MoS 2 /WS 2 slabs. [10][11][12] Numerous substances have been applied as support in the HDS process, including gamma-alumina, zeolites, metal oxides, carbon-based material, silica and their composite. [13][14][15][16] Among of them, gamma-alumina has considered the most commonly used because of low cost, moderate acidsites, considerable mechanical properties and adequate porosity.…”