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A high acid mesoporous USY zeolite prepared by alumination

Ma J., Kang Y., Ma N., Hao W., Wang Y.

Materials Science Poland

2013

Vol. 31, No. 1

19-24

A high-acidity HUSY zeolite with mesoporous structure was prepared by alumination with a dilute aqueous NaAlO2 solution and characterized by XRD, N2 adsorption, IR framework vibration and 29Si MAS NMR methods. The results indicated the extra-framework aluminum was reinserted into the tetrahedral framework through isomorphic substitution of framework Si (0Al) sites by Al ions, whereas the crystal and micropore structure were unaltered. FTIR spectra of hydroxyl vibrations and pyridine adsorbed on realuminated zeolites showed that the number of Brfinsted acid sites and strong Lewis acid sites increased whereas weak Lewis acid sites decreased twice. The mesoporous structure composed of inter-and intra-crystalline pores in the aluminated HUSY increased the external surface area of the zeolite, improving accessibility of molecules to the active sites and enhancing its catalytic ability. The realuminated HUSY zeolite supported with Ru catalyst exhibited a higher catalytic activity for benzene hydrogenation than the parent HUSY zeolite; the reaction rate in comparison to the mesozeolite increased by 5.5 times.

Catalytic hydrogenation in the process of 2-((1-benzylpiperidin-4-yl) methyl)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride synthesis I. Catalyst screening and finding the optimal reaction conditions

Samardzic Z. M., Zrncevic S.

Polish Journal of Chemical Technology

2012

Vol. 14, nr 3

38-47

Catalytic hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl)methylene)-5,6-dimethoxy-2,3-dihydroinden- 1-one hydrochloride () to 2-((1-benzylpiperidin-4-yl)methyl)-5,6-dimethoxy-2,3-dihydroinden- 1-one hydrochloride (2) was investigated in the batch-slurry reactor. The 5% Pt/C catalyst was chosen to search the optimal reaction conditions because of its higher catalytic activity compared to other catalysts used in the work. To investigate the catalyst activity, selectivity and stability, the effect of agitation speed, catalyst loading, solvent, temperature, hydrogen pressure and catalyst reuse were studied. The initial rate of hydrogenation increases with the increase of catalyst loading, with the temperature and solvent polarity, if alcohols were used as solvents. The hydrogenation rate decreases with higher hydrogen pressure and that was explained by competitive adsorption of both reactants. The results also indicate that 5% Pt/C is a promising catalyst for 1 hydrogenation because at relatively mild reaction conditions selectivity towards main product was high (98%) and catalyst maintains its activity during successive runs.