Catalyst H-ZSM 5 in Amines addition on Carbonyl Compounds α, β-unsaturated catalyzed by H-ZSM 5

Background Zeolites are crystallized aluminum silicates. Their structure consists of an arrangement of TO4 tetrahedral (T = Si, Al ...), creating a regular nonporous system made up of channels with a diameter of less than 1 nm and cages (the channel intersections). These materials were discovered by the mineralogist in 1756. These porous materials are used in the paper industry, in jewelry, and in other fields. Certain applications require pure materials with specific properties, hence the need to develop their synthesis. Zeolites are obtained hydrothermally at temperatures below 200°C. The dimensions of the pores are of the order of a nanometer, close to the dimensions of certain organic molecules which make these zeolitic materials find applications in various fields, separation by molecular sieving, purification by adsorption, cation exchange and catalysis. Result We are successful in the reaction of addition the series of amines to unsaturated alkenes, catalyzed by zeolite H-ZSM-5, the results show good products obtained with excellent yields, in short time, pure products can be obtained after filtering the catalyst and then removing the excess amines, the catalyst is recoverable, reactivated and reused several times for other addition reactions, the products were defined by 1 H NMR spectroscopy. Conclusion According to the results obtained. It can be said that the addition of various aliphatic or aromatic amines reacted successfully with alkenes, in the presence of the catalyst H-ZSM-5, to give the corresponding adducts with excellent yields in time and in perfect conditions, solvent-free and room temperature, so our H-ZSM-5 catalyst is effective, can meet our goal of adding amines to unsaturated carbonyl components.

Effects of Framework Disruption of Ga and Ba Containing Zeolitic Materials by Thermal Treatment

The effect of the thermal treatment of some zeolitic materials was studied on oxidative dehydrogenation (ODH) of n-octane. Gallium containing faujasite catalysts were synthesized using isomorphic substitution, specifically, a galosilicalite (Ga-BaY(Sil)) and an aluminosilicalite substituted with gallium (Ga-BaY(IS)), with constant Si/M ratio. The catalysts were thermally treated at different temperatures (250, 550, and 750 °C) before catalytic testing. The quantification of total and strength of acid sites by FT-IR (O-H region), pyridine-IR, and NH3-temperature-programmed desorption (TPD) confirmed a decrease in the number of Brønsted acid sites and an increase in the number of Lewis acid sites upon increasing the calcination temperature. Isothermal n-octane conversion also decreased with the catalysts’ calcination temperature, whereas octene selectivity showed the opposite trend (also at iso-conversion). The COx selectivity showed a decrease over the catalysts calcined from 250 to 550 °C and then an increase over the 750 °C calcined catalysts, which was due to the strong adsorption of products to strong Lewis acid sites on the catalysts leading to the deep oxidation of the products. Only olefinic-cracked products were observed over the 750 °C calcined catalysts. This suggested that the thermal treatment increases Lewis acid sites, which activate n-octane using a bimolecular mechanism, instead of a monomolecular mechanism.