Home – Home – Jornals – Chemistry for Sustainable Development 2018 number 2

High-silica ZSM-5-type zeolite with silica module of 40 was produced by hydrothermal synthesis using hexamethylenediamine as a structure-forming additive. Its belonging to the pentasyl family and crystallization degree were determined by IR spectroscopy and X-ray phase analysis. Metal-containing zeolite catalysts were prepared by mechanical mixing of zeolite with powders of nickel and zirconium with medium particle size of 50 nm and those of rhenium with that of 770 nm in terms of 0.5 mass %. The specific surface area of samples and parameters of their porous structure were determined by BET according to low-temperature nitrogen adsorption, acidic characteristics - by temperature-programmed ammonia desorption. It was demonstrated that the introduction of metals into zeolite reduced its specific surface area and acidity. Catalytic activity of metal-containing zeolites was studied during transformation of propane-butane fraction and n -heptane. It was found that during their joint transformation over unmodified zeolite, the yield of the liquid product and the content of isoalkanes therein were higher than in case of conversion of only n -heptane. The addition of metals to zeolite led to a decrease in the concentration of n -alkanes, arenes, and alkenes in the resulting liquid products over catalysts and to a simultaneous increase in the fraction of iso- and cycloalkanes therein. Modification of zeolite with rhenium and zirconium increased formation selectivity of isoalkanes, while the introduction of nickel - that of aromatic hydrocarbons. The resulting zeolites might be used as the main component of catalysts for gentrification of the straight-run gasoline fraction of oil and during its joint conversion with hydrocarbon gases.