Effect of the order of deposition of the active components on the structure, phase composition, and activity of aluminum-nickel-molybdenum catalysts

Raman spectroscopy, diffuse reflection electron spectroscopy, and x-ray photoelectron spectroscopy were used to study the effect of the impregnation method and roasting temperature on the nature of the compounds formed in aluminum-nickel-molybdenum catalysts and the distribution of elements in the catalyst granule. Impregnation of the support by salts of hydrogenating metals largely gives surface molybdenum poly compounds with the inclusion of nickel, which interact weakly with the support. Upon an increase in the roasting temperature, the interaction of molybdenum and nickel with the support becomes more significant. The order of the deposition of the hydrogenating metals affects the distribution of elements in the catalyst granule and the composition of the surface nickel and molybdenum compounds.