The catalytically active sites of isomorphous substituted MFI structures have been characterized by infrared spectroscopy and microcalorimetric measurements using ammonia and acetonitrile as probe. Due to decreasing heats of NH3 adsorption, the NH3 TPD peak positions, the positions of the IR OH stretching frequencies and their shifts upon adsorption of acetonitrile the Brønsted acid site strength of the modified MFI decreases from Al>Fe> In>> silicalite. In addition to those strong sites weaker Lewis centres due to the non-framework material have been found. For TS-1 comparatively low heats of adsorption due to coordinatively bonded ammonia have been detected. The amounts of adsorption with heats higher than found for silicalite correlates with the amount of Ti in the sample.
|Name||Studies in Surface Science and Catalysis|
|Conference||conference; ZEOCAT ; 11 (Szombathely) : 1995.07.09-13; 1995-07-09; 1995-07-13|
|Period||9/07/95 → 13/07/95|
|Other||ZEOCAT ; 11 (Szombathely) : 1995.07.09-13|