Precursor Of Active Component Research Articles

Sulfide catalysts supported on Al2O3: VI. Synthesis of catalysts with the use of binuclear molybdenum(V) complexes with sulfur-containing ligands

A new method was developed for the preparation of sulfide catalysts supported on aluminum oxide. The surface assembling of a direct precursor of the active component was used in this method. The method consists in the sequential immobilization of binuclear molybdenum complexes with S-containing ligands on the support surface followed by the immobilization of nickel (cobalt) compounds at the surface molybdenum complexes. The complexation and structure of the resulting complexes in solution and the structure of surface complexes were studied by 95Mo and 17O NMR, IR, and EXAFS spectroscopy. The surface assembling of a direct precursor of the active component of sulfide hydrodesulfurization catalysts was demonstrated using IR and EXAFS spectroscopy. The activity of the resulting catalysts in a model reaction of thiophene hydrogenolysis was comparable to the activity of sulfide catalysts of the metal complex origin and was much higher than the activity of commercial catalysts and catalysts prepared by impregnation.

Advanced Metal/Ceramic Catalysts for Hydrogen Generation by Steam Reforming of Hydrocarbons

ABSTRACTThe main features of porous metal/ceramic catalysts for hydrocarbons steam reforming their formation via hydrothermal treatment of the powdered aluminum and lanthanum nickelate mixture in the confined space are elucidated. For catalysts obtained via this route, their polymodal pore structure was found to approach the optimum level. The phase composition of the active component precursor was shown to have a great impact on the specific catalytic activity of catalysts.

Preparation and Evaluation of Skeletal Cobalt-Molybdenum Hydrodesulfurization Catalysts

Preparation of skeletal Co-Mo catalysts by controlled impregnation of aluminosilicate skeletons containing deposited gamma-alumina with aqueous solutions of active component precursors has been investigated. The activity of the laboratory catalysts in gas oil hydrodesulfurization has been determined. Kinetics of impregnation of skeletal supports, the effect of their type, and the dependence of catalyst activity on the content of cobalt and molybdenum sulfides are reported. HDS skeletal catalysts prepared were compared with the extruded types. It was found that skeletal HDS catalysts show the higher activity (related to the content of alumina and Co-Mo sulfides) than the extruded ones due to the less significant effect of internal diffusion. However, if the activity is related to the same volume of catalyst bed, the activity of skeletal catalysts is only one fourth of that of the extruded types.