Periodic DFT calculations of the stability of mononuclear and oligonuclear Ga-oxo cations in mordenite (MOR) have been carried out. Independent of the aluminium distribution in the zeolite framework the stability of cyclic Ga(2)O(2)(2+) ions is much higher than that of the isolated GaO(+) (gallyl) ions in a high-silica mordenite (Si/Al = 23) model. As to the location of such dimers, favorable t...

in this research different types of al2o3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. these supports were al2o3 from merck, axen and gamma al2o3 synthesized from al(oh)3. sn/pt/al2o3 catalysts were prepared by sequential impregnation, at first pt and then sn was deposited. characterization of catalysts was performed by x-ray powder diffraction (xrd)...

Cu-SAPO-34 (Cu-CZC) and Fe-mordenite (Fe-MOR) their mechanical mixture (50 : 50) have been exhaustively investigated by means of operando X-ray absorption spectroscopy under NH3-SCR conditions.

Framework-associated aluminum is demonstrated to facilitate a reversible switch between Lewis and Brønsted acidity in zeolites with the acid sites preferentially populating side-pockets case of mordenite.